fixes for 2nd practical

AGENTS.md

@@ -1,18 +0,0 @@
-# AGENTS.md
-
-## Build/Test Commands
-- Build: `./gradlew build`
-- Test all: `./gradlew test`
-- Run single test: `./gradlew test --tests "FreightIntegrationTest.getByIdReturnsEntity"`
-- Run app: `./gradlew bootRun`
-
-## Code Style Guidelines
-- Package structure: `ua.com.dxrkness.{controller,service,repository,model}`
-- Use Spring Boot annotations (@RestController, @Service, etc.)
-- Records for models with Jackson @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
-- Constructor injection for dependencies
-- JSpecify annotations (@NullMarked, @Nullable) for null safety
-- Integration tests with @SpringBootTest and parameterized tests
-- REST controllers support both JSON and XML media types
-- Use ResponseEntity for HTTP responses with proper status codes
-- OpenAPI documentation with Swagger annotations on controllers

src/main/java/ua/com/dxrkness/client/ApplicationClient.java

@@ -5,8 +5,13 @@ import org.apache.http.entity.StringEntity;
 import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.apache.http.util.EntityUtils;
+import org.springframework.http.HttpMethod;
+import org.springframework.http.HttpStatus;
 import tools.jackson.databind.ObjectMapper;
 import tools.jackson.dataformat.xml.XmlMapper;
+import ua.com.dxrkness.dto.FreightRequest;
+import ua.com.dxrkness.dto.RouteRequest;
+import ua.com.dxrkness.dto.VehicleRequest;
 import ua.com.dxrkness.model.Freight;
 import ua.com.dxrkness.model.Route;
 import ua.com.dxrkness.model.Vehicle;
@@ -23,9 +28,13 @@ public class ApplicationClient {
             testVehicles(client);
             testFreights(client);
             testRoutes(client);
+            testSubResources(client);
+            testStatusFiltering(client);
+            testErrorCases(client);
+            testInterServiceValidation(client);
 
         } catch (Exception e) {
-            System.err.println("error: " + e.getMessage());
+            System.out.println("error: " + e.getMessage());
             e.printStackTrace();
         }
     }
@@ -35,7 +44,7 @@ public class ApplicationClient {
 
         execute(client, new HttpGet(BASE_URL + "/vehicles"), "GET all vehicles");
 
-        Vehicle newVehicle = new Vehicle(0, "Mercedes", "Actros", "AA1234BB", 2023, 18000, Vehicle.Status.AVAILABLE);
+        var newVehicle = new VehicleRequest("Mercedes", "Actros", "AA1234BB", 2023, 18000, Vehicle.Status.AVAILABLE);
         String vehicleXml = xmlMapper.writeValueAsString(newVehicle);
         HttpPost post = new HttpPost(BASE_URL + "/vehicles");
         post.setEntity(new StringEntity(vehicleXml, "UTF-8"));
@@ -48,19 +57,13 @@ public class ApplicationClient {
         execute(client, get, "GET vehicle by ID=0");
         execute(client, new HttpGet(BASE_URL + "/vehicles/999"), "GET vehicle by ID=999 (not found)");
 
-        Vehicle updateVehicle = new Vehicle(1, "Volvo", "FH16", "BB5678CC", 2024, 20000, Vehicle.Status.MAINTENANCE);
-        String updateJson = jsonMapper.writeValueAsString(updateVehicle);
-        HttpPut put = new HttpPut(BASE_URL + "/vehicles/0");
-        put.setEntity(new StringEntity(updateJson, "UTF-8"));
-        put.setHeader("Content-Type", "application/json");
-        execute(client, put, "PUT update vehicle ID=0");
+        var updateVehicle = new VehicleRequest("Volvo", "FH16", "BB5678CC", 2024, 20000, Vehicle.Status.MAINTENANCE);
+        var vehiclePut = createHttpRequest(updateVehicle, "/vehicles/0", HttpMethod.PUT);
+        execute(client, vehiclePut, "PUT update vehicle ID=0");
 
-        Vehicle patchVehicle = new Vehicle(1, "Volvo", "FH16", "BB5678CC", 2024, 20000, Vehicle.Status.IN_TRANSIT);
-        String patchJson = jsonMapper.writeValueAsString(patchVehicle);
-        HttpPatch patch = new HttpPatch(BASE_URL + "/vehicles/0");
-        patch.setEntity(new StringEntity(patchJson, "UTF-8"));
-        patch.setHeader("Content-Type", "application/json");
-        execute(client, patch, "PATCH update vehicle ID=0");
+        var patchVehicle = new VehicleRequest("Volvo", "FH16", "BB5678CC", 2024, 20000, Vehicle.Status.IN_TRANSIT);
+        var vehiclePatch = createHttpRequest(patchVehicle, "/vehicles/0", HttpMethod.PATCH);
+        execute(client, vehiclePatch, "PATCH update vehicle ID=0");
 
         execute(client, new HttpDelete(BASE_URL + "/vehicles/999"), "DELETE vehicle ID=999 (not found)");
 
@@ -73,29 +76,20 @@ public class ApplicationClient {
         execute(client, new HttpGet(BASE_URL + "/freights"), "GET all freights");
 
         Freight.Dimensions dims = new Freight.Dimensions(120, 100, 200);
-        Freight newFreight = new Freight(0, "Electronics", "Laptops and monitors", 500, dims, Freight.Status.PENDING);
-        String freightJson = jsonMapper.writeValueAsString(newFreight);
-        HttpPost post = new HttpPost(BASE_URL + "/freights");
-        post.setEntity(new StringEntity(freightJson, "UTF-8"));
-        post.setHeader("Content-Type", "application/json");
-        execute(client, post, "POST new freight");
+        var newFreight = new FreightRequest("Electronics", "Laptops and monitors", 500, dims, Freight.Status.PENDING);
+        var freightPost = createHttpRequest(newFreight, "/freights", HttpMethod.POST);
+        execute(client, freightPost, "POST new freight");
 
-        execute(client, new HttpGet(BASE_URL + "/freights/0"), "GET freight by ID=1");
+        execute(client, new HttpGet(BASE_URL + "/freights/0"), "GET freight by ID=0");
         execute(client, new HttpGet(BASE_URL + "/freights/999"), "GET freight by ID=999 (not found)");
 
-        Freight updateFreight = new Freight(1, "Furniture", "Office desks", 800, dims, Freight.Status.IN_TRANSIT);
-        String updateJson = jsonMapper.writeValueAsString(updateFreight);
-        HttpPut put = new HttpPut(BASE_URL + "/freights/0");
-        put.setEntity(new StringEntity(updateJson, "UTF-8"));
-        put.setHeader("Content-Type", "application/json");
-        execute(client, put, "PUT update freight ID=1");
+        var updateFreight = new FreightRequest("Furniture", "Office desks", 800, dims, Freight.Status.IN_TRANSIT);
+        var freightPut = createHttpRequest(updateFreight, "/freights/0", HttpMethod.PUT);
+        execute(client, freightPut, "PUT update freight ID=0");
 
-        Freight patchFreight = new Freight(1, "Furniture", "Office desks", 800, dims, Freight.Status.DELIVERED);
-        String patchJson = jsonMapper.writeValueAsString(patchFreight);
-        HttpPatch patch = new HttpPatch(BASE_URL + "/freights/0");
-        patch.setEntity(new StringEntity(patchJson, "UTF-8"));
-        patch.setHeader("Content-Type", "application/json");
-        execute(client, patch, "PATCH update freight ID=1");
+        var patchFreight = new FreightRequest("Furniture", "Office desks", 800, dims, Freight.Status.DELIVERED);
+        var freightPatch = createHttpRequest(patchFreight, "/freights/0", HttpMethod.PATCH);
+        execute(client, freightPatch, "PATCH update freight ID=0");
 
         execute(client, new HttpDelete(BASE_URL + "/freights/999"), "DELETE freight ID=999 (not found)");
 
@@ -105,40 +99,110 @@ public class ApplicationClient {
     private static void testRoutes(CloseableHttpClient client) throws Exception {
         System.out.println("--- ROUTES ---");
 
+        var newRoute = new RouteRequest(0, List.of(0L), "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+        var routePost = createHttpRequest(newRoute, "/routes", HttpMethod.POST);
+        execute(client, routePost, "POST new route");
+
         execute(client, new HttpGet(BASE_URL + "/routes"), "GET all routes");
 
-        execute(client, new HttpGet(BASE_URL + "/routes?vehicleId=0"), "GET routes by vehicleId=1");
-        execute(client, new HttpGet(BASE_URL + "/routes?freightId=0"), "GET routes by freightId=1");
-
-        Route newRoute = new Route(0, 0, List.of(0L, 1L), "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
-        String routeJson = jsonMapper.writeValueAsString(newRoute);
-        HttpPost post = new HttpPost(BASE_URL + "/routes");
-        post.setEntity(new StringEntity(routeJson, "UTF-8"));
-        post.setHeader("Content-Type", "application/json");
-        execute(client, post, "POST new route");
-
         execute(client, new HttpGet(BASE_URL + "/routes/0"), "GET route by ID=0");
         execute(client, new HttpGet(BASE_URL + "/routes/999"), "GET route by ID=999 (not found)");
 
-        Route updateRoute = new Route(1, 1, List.of(1L), "Kyiv", "Odesa", 480.0, 7.0, Route.Status.IN_PROGRESS);
-        String updateJson = jsonMapper.writeValueAsString(updateRoute);
-        HttpPut put = new HttpPut(BASE_URL + "/routes/0");
-        put.setEntity(new StringEntity(updateJson, "UTF-8"));
-        put.setHeader("Content-Type", "application/json");
-        execute(client, put, "PUT update route ID=0");
+        var updateRoute = new RouteRequest(0, List.of(0L), "Kyiv", "Odesa", 480.0, 7.0, Route.Status.IN_PROGRESS);
+        var routePut = createHttpRequest(updateRoute, "/routes/0", HttpMethod.PUT);
+        execute(client, routePut, "PUT update route ID=0");
 
-        Route patchRoute = new Route(1, 1, List.of(1L), "Kyiv", "Odesa", 480.0, 7.0, Route.Status.COMPLETED);
-        String patchJson = jsonMapper.writeValueAsString(patchRoute);
-        HttpPatch patch = new HttpPatch(BASE_URL + "/routes/0");
-        patch.setEntity(new StringEntity(patchJson, "UTF-8"));
-        patch.setHeader("Content-Type", "application/json");
-        execute(client, patch, "PATCH update route ID=0");
+        var patchRoute = new RouteRequest(0, List.of(0L), "Kyiv", "Odesa", 480.0, 7.0, Route.Status.COMPLETED);
+        var routePatch = createHttpRequest(patchRoute, "/routes/0", HttpMethod.PATCH);
+        execute(client, routePatch, "PATCH update route ID=0");
 
         execute(client, new HttpDelete(BASE_URL + "/routes/999"), "DELETE route ID=999 (not found)");
 
         System.out.println();
     }
 
+    private static void testSubResources(CloseableHttpClient client) throws Exception {
+        System.out.println("--- SUB-RESOURCES ---");
+
+        execute(client, new HttpGet(BASE_URL + "/routes/0/freights"), "GET freights for route ID=0 (sub-resource)");
+        execute(client, new HttpGet(BASE_URL + "/routes/0/vehicle"), "GET vehicle for route ID=0 (sub-resource)");
+
+        System.out.println();
+    }
+
+    private static void testStatusFiltering(CloseableHttpClient client) throws Exception {
+        System.out.println("--- STATUS FILTERING ---");
+
+        execute(client, new HttpGet(BASE_URL + "/vehicles?status=AVAILABLE"), "GET vehicles with status=AVAILABLE");
+        execute(client, new HttpGet(BASE_URL + "/vehicles?status=IN_TRANSIT"), "GET vehicles with status=IN_TRANSIT");
+        execute(client, new HttpGet(BASE_URL + "/freights?status=PENDING"), "GET freights with status=PENDING");
+        execute(client, new HttpGet(BASE_URL + "/freights?status=DELIVERED"), "GET freights with status=DELIVERED");
+        execute(client, new HttpGet(BASE_URL + "/routes?status=PLANNED"), "GET routes with status=PLANNED");
+        execute(client, new HttpGet(BASE_URL + "/routes?status=COMPLETED"), "GET routes with status=COMPLETED");
+
+        System.out.println();
+    }
+
+    private static void testErrorCases(CloseableHttpClient client) throws Exception {
+        System.out.println("--- ERROR CASES (TESTING EXCEPTION HANDLING) ---");
+
+        execute(client, new HttpGet(BASE_URL + "/vehicles/999"), "GET non-existent vehicle (404 Not Found)");
+        execute(client, new HttpGet(BASE_URL + "/freights/-1"), "GET freight with invalid ID (404 Not Found)");
+        execute(client, new HttpGet(BASE_URL + "/routes/-1"), "GET route with invalid ID (404 Not Found)");
+
+        System.out.println();
+    }
+
+    private static void testInterServiceValidation(CloseableHttpClient client) throws Exception {
+        System.out.println("--- INTER-SERVICE COMMUNICATION & VALIDATION ---");
+
+        // Test 1: Create route with valid references (should succeed)
+        System.out.println("[INTER-SERVICE TEST 1] Creating route with valid vehicle and freight references:");
+        var validRoute = new RouteRequest(0, List.of(0L), "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+        var validRoutePost = createHttpRequest(validRoute, "/routes", HttpMethod.POST);
+        execute(client, validRoutePost, "POST route with valid vehicle and freights (should succeed)");
+
+        // Test 2: Create route with invalid vehicle (should fail with 404)
+        System.out.println("[INTER-SERVICE TEST 2] Creating route with INVALID vehicle ID:");
+        Route invalidVehicleRoute = new Route(0, -999, List.of(1L), "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+        var invalidRoutePost = createHttpRequest(invalidVehicleRoute, "/routes", HttpMethod.POST);
+        execute(client, invalidRoutePost, "POST route with invalid vehicle ID, should result in 404");
+
+        // Test 3: Create route with invalid freight (should fail with 404)
+        System.out.println("[INTER-SERVICE TEST 3] Creating route with INVALID freight ID:");
+        Route invalidFreightRoute = new Route(0, 0, List.of(-999L), "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+        var invalidFreightPost = createHttpRequest(invalidFreightRoute, "/routes", HttpMethod.POST);
+        execute(client, invalidFreightPost, "POST route with invalid freight ID, should result in 404");
+    }
+
+    private static <T> HttpUriRequest createHttpRequest(T entity, String path, HttpMethod method) {
+        String entityJson = jsonMapper.writeValueAsString(entity);
+        HttpEntityEnclosingRequestBase req;
+
+        if (method == HttpMethod.GET) {
+            return new HttpGet(BASE_URL + path);
+        } else if (method == HttpMethod.POST) {
+            req = new HttpPost(BASE_URL + path);
+            req.setEntity(new StringEntity(entityJson, "UTF-8"));
+            req.setHeader("Content-Type", "application/json");
+            return req;
+        } else if (method == HttpMethod.PUT) {
+            req = new HttpPut(BASE_URL + path);
+            req.setEntity(new StringEntity(entityJson, "UTF-8"));
+            req.setHeader("Content-Type", "application/json");
+            return req;
+        } else if (method == HttpMethod.PATCH) {
+            req = new HttpPatch(BASE_URL + path);
+            req.setEntity(new StringEntity(entityJson, "UTF-8"));
+            req.setHeader("Content-Type", "application/json");
+            return req;
+        } else if (method == HttpMethod.DELETE) {
+            return new HttpDelete(BASE_URL + path);
+        } else {
+            throw new IllegalArgumentException("method is invalid");
+        }
+    }
+
     private static String execute(CloseableHttpClient client, HttpUriRequest request, String description) {
         try {
             System.out.println("[" + request.getMethod() + "] " + description);
@@ -151,14 +215,14 @@ public class ApplicationClient {
                 System.out.println("Response: " + body);
             }
 
-            if (statusCode >= 400) {
-                System.err.println("ERROR: Request failed with status " + statusCode);
+            if (HttpStatus.valueOf(statusCode).isError()) {
+                System.out.println("ERROR: Request failed with status " + statusCode);
             }
 
             System.out.println();
             return body;
         } catch (Exception e) {
-            System.err.println("EXCEPTION: " + e.getMessage());
+            System.out.println("EXCEPTION: " + e.getMessage());
             e.printStackTrace();
             System.out.println();
             return null;

src/main/java/ua/com/dxrkness/controller/FreightController.java

@@ -1,14 +1,14 @@
 package ua.com.dxrkness.controller;
 
 import io.swagger.v3.oas.annotations.Operation;
-import io.swagger.v3.oas.annotations.media.Content;
-import io.swagger.v3.oas.annotations.media.Schema;
+import io.swagger.v3.oas.annotations.Parameter;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.tags.Tag;
-import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
+import ua.com.dxrkness.dto.FreightRequest;
+import ua.com.dxrkness.dto.FreightResponse;
 import ua.com.dxrkness.model.Freight;
 import ua.com.dxrkness.service.FreightService;
 
@@ -21,7 +21,6 @@ import java.util.List;
         consumes = {MediaType.APPLICATION_JSON_VALUE, MediaType.APPLICATION_XML_VALUE}
 )
 @Tag(name = "Freight", description = "Freights management")
-@NullMarked
 public class FreightController {
     private final FreightService service;
 
@@ -31,19 +30,20 @@ public class FreightController {
 
     @Operation(
             summary = "Retrieve all freights",
-            description = "Gets a list of all freight records in the system"
+            description = "Gets a list of all freight records in the system or filter by status"
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Successfully retrieved list of freights (may be empty!)",
-            content = @Content(
-                    mediaType = MediaType.APPLICATION_JSON_VALUE,
-                    schema = @Schema(implementation = Freight.class)
-            )
+            description = "Successfully retrieved list of freights (may be empty!)"
     )
     @GetMapping(consumes = MediaType.ALL_VALUE)
-    public List<Freight> getAll() {
-        return service.getAll();
+    public List<Freight> getAll(
+            @Parameter(description = "Filter freights by status (PENDING, IN_TRANSIT, DELIVERED)")
+            @RequestParam(name = "status", required = false) Freight.@Nullable Status status) {
+        if (status != null) {
+            return service.getByStatus(status).stream().map(FreightResponse::toEntity).toList();
+        }
+        return service.getAll().stream().map(FreightResponse::toEntity).toList();
     }
 
     @Operation(
@@ -52,19 +52,15 @@ public class FreightController {
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Successfully retrieved freight",
-            content = @Content(
-                    mediaType = MediaType.APPLICATION_JSON_VALUE,
-                    schema = @Schema(implementation = Freight.class)
-            )
+            description = "Successfully retrieved freight"
     )
     @ApiResponse(
             responseCode = "404",
             description = "Freight not found"
     )
     @GetMapping(value = "/{id}", consumes = MediaType.ALL_VALUE)
-    public ResponseEntity<Freight> getById(@PathVariable("id") long id) {
-        return ResponseEntity.ofNullable(service.getById(id));
+    public Freight getById(@PathVariable("id") long id) {
+        return service.getById(id).toEntity();
     }
 
     @Operation(
@@ -73,19 +69,15 @@ public class FreightController {
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Freight successfully created",
-            content = @Content(
-                    mediaType = MediaType.APPLICATION_JSON_VALUE,
-                    schema = @Schema(implementation = Freight.class)
-            )
+            description = "Freight successfully created"
     )
     @ApiResponse(
             responseCode = "400",
-            description = "Invalid input"
+            description = "Invalid freight data (e.g., weight exceeds vehicle capacity)"
     )
     @PostMapping
-    public ResponseEntity<Freight> add(@RequestBody Freight newFreight) {
-        return ResponseEntity.ok(service.add(newFreight));
+    public Freight add(@RequestBody FreightRequest newFreight) {
+        return service.add(newFreight).toEntity();
     }
 
     @Operation(
@@ -94,19 +86,15 @@ public class FreightController {
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Freight successfully updated",
-            content = @Content(
-                    mediaType = MediaType.APPLICATION_JSON_VALUE,
-                    schema = @Schema(implementation = Freight.class)
-            )
+            description = "Freight successfully updated"
     )
     @ApiResponse(
             responseCode = "400",
             description = "Invalid input"
     )
     @PutMapping("/{id}")
-    public ResponseEntity<Freight> update(@PathVariable("id") long id, @RequestBody Freight newFreight) {
-        return ResponseEntity.ok(service.update(id, newFreight));
+    public Freight update(@PathVariable("id") long id, @RequestBody FreightRequest newFreight) {
+        return service.update(id, newFreight).toEntity();
     }
 
     @Operation(
@@ -115,19 +103,15 @@ public class FreightController {
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Freight successfully updated",
-            content = @Content(
-                    mediaType = MediaType.APPLICATION_JSON_VALUE,
-                    schema = @Schema(implementation = Freight.class)
-            )
+            description = "Freight successfully updated"
     )
     @ApiResponse(
             responseCode = "400",
             description = "Invalid input"
     )
     @PatchMapping("/{id}")
-    public ResponseEntity<Freight> updatePatch(@PathVariable("id") long id, @RequestBody Freight newFreight) {
-        return ResponseEntity.ok(service.update(id, newFreight));
+    public Freight updatePatch(@PathVariable("id") long id, @RequestBody FreightRequest newFreight) {
+        return service.update(id, newFreight).toEntity();
     }
 
     @Operation(
@@ -136,18 +120,14 @@ public class FreightController {
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Freight successfully deleted",
-            content = @Content(
-                    mediaType = MediaType.APPLICATION_JSON_VALUE,
-                    schema = @Schema(implementation = Freight.class)
-            )
+            description = "Freight successfully deleted"
     )
     @ApiResponse(
             responseCode = "404",
             description = "Freight not found"
     )
     @DeleteMapping(value = "/{id}", consumes = MediaType.ALL_VALUE)
-    public ResponseEntity<Freight> delete(@PathVariable("id") long id) {
-        return ResponseEntity.ofNullable(service.delete(id));
+    public Freight delete(@PathVariable("id") long id) {
+        return service.delete(id).toEntity();
     }
 }

src/main/java/ua/com/dxrkness/controller/GlobalExceptionHandler.java

@@ -0,0 +1,39 @@
+package ua.com.dxrkness.controller;
+
+import org.jspecify.annotations.NullMarked;
+import org.springframework.http.HttpStatus;
+import org.springframework.web.ErrorResponse;
+import org.springframework.web.bind.annotation.ExceptionHandler;
+import org.springframework.web.bind.annotation.RestControllerAdvice;
+import ua.com.dxrkness.exception.FreightNotFoundException;
+import ua.com.dxrkness.exception.RouteNotFoundException;
+import ua.com.dxrkness.exception.VehicleNotFoundException;
+
+
+@RestControllerAdvice
+@NullMarked
+public class GlobalExceptionHandler {
+
+    @ExceptionHandler(exception = {
+            VehicleNotFoundException.class,
+            FreightNotFoundException.class,
+            RouteNotFoundException.class
+    })
+    public ErrorResponse handleVehicleNotFoundException(Exception ex) {
+        return constructExceptionBody(HttpStatus.NOT_FOUND, ex);
+    }
+
+    @ExceptionHandler(IllegalArgumentException.class)
+    public ErrorResponse handleIllegalArgumentException(IllegalArgumentException ex) {
+        return constructExceptionBody(HttpStatus.BAD_REQUEST, ex);
+    }
+
+    @ExceptionHandler(Exception.class)
+    public ErrorResponse handleGeneralException(Exception ex) {
+        return constructExceptionBody(HttpStatus.INTERNAL_SERVER_ERROR, ex);
+    }
+
+    private static ErrorResponse constructExceptionBody(HttpStatus errorStatus, Exception ex) {
+        return ErrorResponse.builder(ex, errorStatus, ex.getMessage()).build();
+    }
+}

src/main/java/ua/com/dxrkness/controller/RouteController.java

@@ -2,19 +2,24 @@ package ua.com.dxrkness.controller;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
-import io.swagger.v3.oas.annotations.media.Content;
-import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import org.jspecify.annotations.NullMarked;
 import org.jspecify.annotations.Nullable;
 import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
+import ua.com.dxrkness.dto.RouteRequest;
+import ua.com.dxrkness.dto.RouteResponse;
+import ua.com.dxrkness.model.Freight;
 import ua.com.dxrkness.model.Route;
+import ua.com.dxrkness.model.Vehicle;
+import ua.com.dxrkness.service.FreightService;
 import ua.com.dxrkness.service.RouteService;
+import ua.com.dxrkness.service.VehicleService;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.stream.Stream;
 
 @RestController
 @RequestMapping(
@@ -25,128 +30,48 @@ import java.util.List;
 @Tag(name = "Route", description = "Routes management")
 @NullMarked
 public class RouteController {
-    private final RouteService service;
+    private final RouteService routeService;
+    private final VehicleService vehicleService;
+    private final FreightService freightService;
 
-    public RouteController(RouteService service) {
-        this.service = service;
+    public RouteController(RouteService routeService,
+                           VehicleService vehicleService,
+                           FreightService freightService) {
+        this.routeService = routeService;
+        this.vehicleService = vehicleService;
+        this.freightService = freightService;
     }
 
     @Operation(
             summary = "Get routes",
-            description = "Get all routes or filter by freight ID/vehicle ID. May result in empty list!"
+            description = "Get all routes or filter by freight ID/vehicle ID/status. May result in empty list!"
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Successfully retrieved routes",
-            content = @Content(
-                    schema = @Schema(implementation = Route.class)
-            )
+            description = "Successfully retrieved routes"
     )
     @GetMapping(consumes = MediaType.ALL_VALUE)
     public List<Route> getAll(
             @Parameter(description = "Filter routes by freight ID")
             @RequestParam(name = "freightId", required = false) @Nullable Long freightId,
             @Parameter(description = "Filter routes by vehicle ID")
-            @RequestParam(name = "vehicleId", required = false) @Nullable Long vehicleId) {
+            @RequestParam(name = "vehicleId", required = false) @Nullable Long vehicleId,
+            @Parameter(description = "Filter routes by status (PLANNED, IN_PROGRESS, COMPLETED, CANCELLED)")
+            @RequestParam(name = "status", required = false) Route.@Nullable Status status) {
+        if (status != null) {
+            return routeService.getByStatus(status).stream().map(RouteResponse::toEntity).toList();
+        }
         if (vehicleId != null) {
-            return service.getByVehicleId(vehicleId);
+            return routeService.getByVehicleId(vehicleId).stream().map(RouteResponse::toEntity).toList();
         }
         if (freightId != null) {
-            var route = service.getByFreightId(freightId);
+            var route = routeService.getByFreightId(freightId);
             if (route == null) {
                 return List.of();
             }
-            return List.of(route);
+            return Stream.of(route).map(RouteResponse::toEntity).toList();
         }
-        return service.getAll();
-    }
-
-    @Operation(
-            summary = "Create new route",
-            description = "Add new route"
-    )
-    @ApiResponse(
-            responseCode = "200",
-            description = "Route successfully created",
-            content = @Content(
-                    schema = @Schema(implementation = Route.class)
-            )
-    )
-    @ApiResponse(
-            responseCode = "400",
-            description = "Invalid route data provided"
-    )
-    @PostMapping
-    public ResponseEntity<Route> add(
-            @io.swagger.v3.oas.annotations.parameters.RequestBody(
-                    description = "Route object to be created",
-                    required = true,
-                    content = @Content(
-                            schema = @Schema(implementation = Route.class)
-                    )
-            )
-            @RequestBody Route newRoute) {
-        return ResponseEntity.ok(service.add(newRoute));
-    }
-
-    @Operation(
-            summary = "Update a route (full)",
-            description = "Update all fields of an existing route by ID"
-    )
-    @ApiResponse(
-            responseCode = "200",
-            description = "Route successfully updated",
-            content = @Content(
-                    schema = @Schema(implementation = Route.class)
-            )
-    )
-    @ApiResponse(
-            responseCode = "400",
-            description = "Invalid route data provided"
-    )
-    @PutMapping("/{id}")
-    public ResponseEntity<Route> update(
-            @Parameter(description = "ID of the route to update", required = true)
-            @PathVariable("id") long id,
-            @io.swagger.v3.oas.annotations.parameters.RequestBody(
-                    description = "Updated route object",
-                    required = true,
-                    content = @Content(
-                            schema = @Schema(implementation = Route.class)
-                    )
-            )
-            @RequestBody Route newRoute) {
-        return ResponseEntity.ok(service.update(id, newRoute));
-    }
-
-    @Operation(
-            summary = "Update a route (partial)",
-            description = "Update specific fields of an existing route by ID"
-    )
-    @ApiResponse(
-            responseCode = "200",
-            description = "Route successfully updated",
-            content = @Content(
-                    schema = @Schema(implementation = Route.class)
-            )
-    )
-    @ApiResponse(
-            responseCode = "400",
-            description = "Invalid route data provided"
-    )
-    @PatchMapping("/{id}")
-    public ResponseEntity<Route> updatePatch(
-            @Parameter(description = "ID of the route to update", required = true)
-            @PathVariable("id") long id,
-            @io.swagger.v3.oas.annotations.parameters.RequestBody(
-                    description = "Route object with fields to update",
-                    required = true,
-                    content = @Content(
-                            schema = @Schema(implementation = Route.class)
-                    )
-            )
-            @RequestBody Route newRoute) {
-        return ResponseEntity.ok(service.update(id, newRoute));
+        return routeService.getAll().stream().map(RouteResponse::toEntity).toList();
     }
 
     @Operation(
@@ -155,40 +80,151 @@ public class RouteController {
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Route found",
-            content = @Content(
-                    schema = @Schema(implementation = Route.class)
-            )
+            description = "Route found"
     )
     @ApiResponse(
             responseCode = "404",
             description = "Route not found"
     )
     @GetMapping(value = "/{id}", consumes = MediaType.ALL_VALUE)
-    public ResponseEntity<Route> getById(
+    public Route getById(
             @Parameter(description = "ID of the route to retrieve", required = true)
             @PathVariable("id") long id) {
-        return ResponseEntity.ofNullable(service.getById(id));
+        return routeService.getById(id).toEntity();
     }
 
+    @Operation(
+            summary = "Retrieve a vehicle by route ID"
+    )
+    @ApiResponse(
+            responseCode = "200",
+            description = "Route and vehicle found"
+    )
+    @ApiResponse(
+            responseCode = "404",
+            description = "Route or vehicle not found"
+    )
+    @GetMapping(value = "/{id}/vehicle", consumes = MediaType.ALL_VALUE)
+    public Vehicle getVehicleById(
+            @Parameter(description = "ID of the route to retrieve", required = true)
+            @PathVariable("id") long id) {
+        return vehicleService.getById(routeService.getById(id).vehicleId()).toVehicle();
+    }
+
+    @Operation(
+            summary = "Retrieve freights by route ID"
+    )
+    @ApiResponse(
+            responseCode = "200",
+            description = "Route and freights found"
+    )
+    @ApiResponse(
+            responseCode = "404",
+            description = "Route or freight not found"
+    )
+    @GetMapping(value = "/{id}/freights", consumes = MediaType.ALL_VALUE)
+    public List<Freight> getFreightsById(
+            @Parameter(description = "ID of the route to retrieve", required = true)
+            @PathVariable("id") long id) {
+        var route = routeService.getById(id);
+        var freights = new ArrayList<Freight>();
+        for (var freightId : route.freightId()) {
+            freights.add(freightService.getById(freightId).toEntity());
+        }
+        return freights;
+    }
+
+    @Operation(
+            summary = "Create new route",
+            description = "Add new route"
+    )
+    @ApiResponse(
+            responseCode = "200",
+            description = "Route successfully created"
+    )
+    @ApiResponse(
+            responseCode = "400",
+            description = "Invalid route data: vehicle or freight not found"
+    )
+    @ApiResponse(
+            responseCode = "404",
+            description = "Referenced vehicle or freight not found"
+    )
+    @PostMapping
+    public Route add(
+            @io.swagger.v3.oas.annotations.parameters.RequestBody(
+                    description = "Route object to be created. Must include valid vehicleId and freightId list.",
+                    required = true
+            )
+            @RequestBody RouteRequest newRoute) {
+        return routeService.add(newRoute).toEntity();
+    }
+
+    @Operation(
+            summary = "Update a route (full)",
+            description = "Update all fields of an existing route by ID"
+    )
+    @ApiResponse(
+            responseCode = "200",
+            description = "Route successfully updated"
+    )
+    @ApiResponse(
+            responseCode = "400",
+            description = "Invalid route data provided"
+    )
+    @PutMapping("/{id}")
+    public Route update(
+            @Parameter(description = "ID of the route to update", required = true)
+            @PathVariable("id") long id,
+            @io.swagger.v3.oas.annotations.parameters.RequestBody(
+                    description = "Updated route object",
+                    required = true
+            )
+            @RequestBody RouteRequest newRoute) {
+        return routeService.update(id, newRoute).toEntity();
+    }
+
+    @Operation(
+            summary = "Update a route (partial)",
+            description = "Update specific fields of an existing route by ID"
+    )
+    @ApiResponse(
+            responseCode = "200",
+            description = "Route successfully updated"
+    )
+    @ApiResponse(
+            responseCode = "400",
+            description = "Invalid route data provided"
+    )
+    @PatchMapping("/{id}")
+    public Route updatePatch(
+            @Parameter(description = "ID of the route to update", required = true)
+            @PathVariable("id") long id,
+            @io.swagger.v3.oas.annotations.parameters.RequestBody(
+                    description = "Route object with fields to update",
+                    required = true
+            )
+            @RequestBody RouteRequest newRoute) {
+        return routeService.update(id, newRoute).toEntity();
+    }
+
+
     @Operation(
             summary = "Delete a route",
             description = "Delete a route by ID"
     )
     @ApiResponse(
             responseCode = "200",
-            description = "Route successfully deleted",
-            content = @Content(schema = @Schema(implementation = Route.class)
-            )
+            description = "Route successfully deleted"
     )
     @ApiResponse(
             responseCode = "404",
             description = "Route not found"
     )
     @DeleteMapping(value = "/{id}", consumes = MediaType.ALL_VALUE)
-    public ResponseEntity<Route> delete(
+    public Route delete(
             @Parameter(description = "ID of the route to delete", required = true)
             @PathVariable("id") long id) {
-        return ResponseEntity.ofNullable(service.delete(id));
+        return routeService.delete(id).toEntity();
     }
 }

src/main/java/ua/com/dxrkness/controller/VehicleController.java

@@ -2,14 +2,14 @@ package ua.com.dxrkness.controller;
 
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.Parameter;
-import io.swagger.v3.oas.annotations.media.Content;
-import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import io.swagger.v3.oas.annotations.tags.Tag;
 import org.jspecify.annotations.NullMarked;
+import org.jspecify.annotations.Nullable;
 import org.springframework.http.MediaType;
-import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.*;
+import ua.com.dxrkness.dto.VehicleRequest;
+import ua.com.dxrkness.dto.VehicleResponse;
 import ua.com.dxrkness.model.Vehicle;
 import ua.com.dxrkness.service.VehicleService;
 
@@ -32,82 +32,82 @@ public class VehicleController {
 
     @Operation(
             summary = "Retrieve all vehicles",
-            description = "Get a list of all vehicles"
+            description = "Get a list of all vehicles or filter by status"
     )
-    @ApiResponse(responseCode = "200", description = "Successfully retrieved list of vehicles",
-            content = @Content(schema = @Schema(implementation = Vehicle.class)))
+    @ApiResponse(responseCode = "200", description = "Successfully retrieved list of vehicles")
     @GetMapping(consumes = MediaType.ALL_VALUE)
-    public List<Vehicle> getAll() {
-        return service.getAll();
+    public List<Vehicle> getAll(
+            @Parameter(description = "Filter vehicles by status (AVAILABLE, IN_TRANSIT, MAINTENANCE)")
+            @RequestParam(name = "status", required = false) Vehicle.@Nullable Status status) {
+        if (status != null) {
+            return service.getByStatus(status).stream().map(VehicleResponse::toVehicle).toList();
+        }
+        return service.getAll().stream().map(VehicleResponse::toVehicle).toList();
     }
 
     @Operation(
             summary = "Retrieve a vehicle by ID",
             description = "Get a single vehicle by its ID"
     )
-    @ApiResponse(responseCode = "200", description = "Vehicle found",
-            content = @Content(schema = @Schema(implementation = Vehicle.class)))
+    @ApiResponse(responseCode = "200", description = "Vehicle found")
     @ApiResponse(responseCode = "404", description = "Vehicle not found")
     @GetMapping(value = "/{id}", consumes = MediaType.ALL_VALUE)
-    public ResponseEntity<Vehicle> getById(
+    public Vehicle getById(
             @Parameter(description = "ID of the vehicle to retrieve", required = true)
             @PathVariable("id") long id) {
-        return ResponseEntity.ofNullable(service.getById(id));
+        return service.getById(id).toVehicle();
     }
 
     @Operation(
             summary = "Create a new vehicle",
             description = "Add a new vehicle to the system"
     )
-    @ApiResponse(responseCode = "200", description = "Vehicle successfully created",
-            content = @Content(schema = @Schema(implementation = Vehicle.class)))
+    @ApiResponse(responseCode = "200", description = "Vehicle successfully created")
     @ApiResponse(responseCode = "400", description = "Invalid vehicle data provided")
     @PostMapping
-    public ResponseEntity<Vehicle> add(
+    public Vehicle add(
             @io.swagger.v3.oas.annotations.parameters.RequestBody(
                     description = "Vehicle object to be created",
-                    required = true,
-                    content = @Content(schema = @Schema(implementation = Vehicle.class)))
-            @RequestBody Vehicle newVehicle) {
-        return ResponseEntity.ok(service.add(newVehicle));
+                    required = true
+            )
+            @RequestBody VehicleRequest newVehicle) {
+        return service.add(newVehicle).toVehicle();
     }
 
     @Operation(
             summary = "Update a vehicle (full)",
             description = "Update all fields of an existing vehicle by ID"
     )
-    @ApiResponse(responseCode = "200", description = "Vehicle successfully updated",
-            content = @Content(schema = @Schema(implementation = Vehicle.class)))
+    @ApiResponse(responseCode = "200", description = "Vehicle successfully updated")
     @ApiResponse(responseCode = "400", description = "Invalid vehicle data provided")
     @PutMapping("/{id}")
-    public ResponseEntity<Vehicle> update(
+    public Vehicle update(
             @Parameter(description = "ID of the vehicle to update", required = true)
             @PathVariable("id") long id,
             @io.swagger.v3.oas.annotations.parameters.RequestBody(
                     description = "Updated vehicle object",
-                    required = true,
-                    content = @Content(schema = @Schema(implementation = Vehicle.class)))
-            @RequestBody Vehicle newVehicle) {
-        return ResponseEntity.ok(service.update(id, newVehicle));
+                    required = true
+            )
+            @RequestBody VehicleRequest newVehicle) {
+        return service.update(id, newVehicle).toVehicle();
     }
 
     @Operation(
             summary = "Update a vehicle (partial)",
             description = "Update specific fields of an existing vehicle by ID"
     )
-    @ApiResponse(responseCode = "200", description = "Vehicle successfully updated",
-            content = @Content(schema = @Schema(implementation = Vehicle.class)))
+    @ApiResponse(responseCode = "200", description = "Vehicle successfully updated")
     @ApiResponse(responseCode = "400", description = "Invalid vehicle data provided")
     @PatchMapping("/{id}")
-    public ResponseEntity<Vehicle> updatePatch(
+    public Vehicle updatePatch(
             @Parameter(description = "ID of the vehicle to update", required = true)
             @PathVariable("id") long id,
             @io.swagger.v3.oas.annotations.parameters.RequestBody(
                     description = "Vehicle object with fields to update",
-                    required = true,
-                    content = @Content(schema = @Schema(implementation = Vehicle.class)))
-            @RequestBody Vehicle newVehicle) {
-        return ResponseEntity.ok(service.update(id, newVehicle));
+                    required = true
+            )
+            @RequestBody VehicleRequest newVehicle) {
+        return service.update(id, newVehicle).toVehicle();
     }
 
 
@@ -115,13 +115,12 @@ public class VehicleController {
             summary = "Delete a vehicle",
             description = "Delete a vehicle by its ID"
     )
-    @ApiResponse(responseCode = "200", description = "Vehicle successfully deleted",
-            content = @Content(schema = @Schema(implementation = Vehicle.class)))
+    @ApiResponse(responseCode = "200", description = "Vehicle successfully deleted")
     @ApiResponse(responseCode = "404", description = "Vehicle not found")
     @DeleteMapping(value = "/{id}", consumes = MediaType.ALL_VALUE)
-    public ResponseEntity<Vehicle> delete(
+    public Vehicle delete(
             @Parameter(description = "ID of the vehicle to delete", required = true)
             @PathVariable("id") long id) {
-        return ResponseEntity.ofNullable(service.delete(id));
+        return service.delete(id).toVehicle();
     }
 }

src/main/java/ua/com/dxrkness/dto/FreightDto.java

@@ -0,0 +1,34 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Freight;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record FreightDto(
+        String name,
+        String description,
+        int weightKg,
+        Freight.Dimensions dimensions,
+        Freight.Status status
+) {
+    public static FreightDto fromFreight(Freight freight) {
+        return new FreightDto(
+                freight.name(),
+                freight.description(),
+                freight.weightKg(),
+                freight.dimensions(),
+                freight.status()
+        );
+    }
+
+    public static FreightDto fromResponse(FreightResponse freight) {
+        return new FreightDto(
+                freight.name(),
+                freight.description(),
+                freight.weightKg(),
+                freight.dimensions(),
+                freight.status()
+        );
+    }
+}

src/main/java/ua/com/dxrkness/dto/FreightRequest.java

@@ -0,0 +1,19 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Freight;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record FreightRequest(
+        String name,
+        String description,
+        int weightKg,
+        Freight.Dimensions dimensions,
+        Freight.Status status
+) {
+    public Freight toEntity() {
+        return new Freight(0, name, description, weightKg, dimensions, status);
+    }
+}

src/main/java/ua/com/dxrkness/dto/FreightResponse.java

@@ -0,0 +1,23 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Freight;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record FreightResponse(
+        String name,
+        String description,
+        int weightKg,
+        Freight.Dimensions dimensions,
+        Freight.Status status
+) {
+    public Freight toEntity() {
+        return new Freight(0, name, description, weightKg, dimensions, status);
+    }
+
+    public static FreightResponse fromEntity(Freight freight) {
+        return new FreightResponse(freight.name(), freight.description(), freight.weightKg(), freight.dimensions(), freight.status());
+    }
+}

src/main/java/ua/com/dxrkness/dto/RouteDto.java

@@ -0,0 +1,32 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Route;
+
+import java.util.List;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record RouteDto(
+        long id,
+        long vehicleId,
+        List<Long> freightId,
+        String startLocation,
+        String endLocation,
+        Double distanceKm,
+        Double estimatedDurationHours,
+        Route.Status status
+) {
+    public static RouteDto fromRoute(Route route) {
+        return new RouteDto(
+                route.id(),
+                route.vehicleId(),
+                route.freightId(),
+                route.startLocation(),
+                route.endLocation(),
+                route.distanceKm(),
+                route.estimatedDurationHours(),
+                route.status()
+        );
+    }
+}

src/main/java/ua/com/dxrkness/dto/RouteRequest.java

@@ -0,0 +1,21 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Route;
+
+import java.util.List;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record RouteRequest(long vehicleId,
+                           List<Long> freightId,
+                           String startLocation,
+                           String endLocation,
+                           Double distanceKm,
+                           Double estimatedDurationHours,
+                           Route.Status status) {
+    public Route toEntity() {
+        return new Route(0, vehicleId, freightId, startLocation, endLocation, distanceKm, estimatedDurationHours, status);
+    }
+}

src/main/java/ua/com/dxrkness/dto/RouteResponse.java

@@ -0,0 +1,25 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Route;
+
+import java.util.List;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record RouteResponse(long vehicleId,
+                            List<Long> freightId,
+                            String startLocation,
+                            String endLocation,
+                            Double distanceKm,
+                            Double estimatedDurationHours,
+                            Route.Status status) {
+    public Route toEntity() {
+        return new Route(0, vehicleId, freightId, startLocation, endLocation, distanceKm, estimatedDurationHours, status);
+    }
+
+    public static RouteResponse fromRoute(Route route) {
+        return new RouteResponse(route.vehicleId(), route.freightId(), route.startLocation(), route.endLocation(), route.distanceKm(), route.estimatedDurationHours(), route.status());
+    }
+}

src/main/java/ua/com/dxrkness/dto/VehicleDto.java

@@ -0,0 +1,52 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Vehicle;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record VehicleDto(
+        long id,
+        String brand,
+        String model,
+        String licensePlate,
+        int year,
+        int capacityKg,
+        Vehicle.Status status
+) {
+    public static VehicleDto fromVehicle(Vehicle vehicle) {
+        return new VehicleDto(
+                vehicle.id(),
+                vehicle.brand(),
+                vehicle.model(),
+                vehicle.licensePlate(),
+                vehicle.year(),
+                vehicle.capacityKg(),
+                vehicle.status()
+        );
+    }
+
+    public static VehicleDto fromResponse(VehicleResponse vehicle) {
+        return new VehicleDto(
+                vehicle.id(),
+                vehicle.brand(),
+                vehicle.model(),
+                vehicle.licensePlate(),
+                vehicle.year(),
+                vehicle.capacityKg(),
+                vehicle.status()
+        );
+    }
+
+    public Vehicle toVehicle() {
+        return new Vehicle(
+                this.id(),
+                this.brand(),
+                this.model(),
+                this.licensePlate(),
+                this.year(),
+                this.capacityKg(),
+                this.status()
+        );
+    }
+}

src/main/java/ua/com/dxrkness/dto/VehicleRequest.java

@@ -0,0 +1,20 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Vehicle;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record VehicleRequest(
+        String brand,
+        String model,
+        String licensePlate,
+        int year,
+        int capacityKg,
+        Vehicle.Status status
+) {
+    public Vehicle toEntity() {
+        return new Vehicle(0, brand, model, licensePlate, year, capacityKg, status);
+    }
+}

src/main/java/ua/com/dxrkness/dto/VehicleResponse.java

@@ -0,0 +1,40 @@
+package ua.com.dxrkness.dto;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import ua.com.dxrkness.model.Vehicle;
+
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public record VehicleResponse(
+        long id,
+        String brand,
+        String model,
+        String licensePlate,
+        int year,
+        int capacityKg,
+        Vehicle.Status status
+) {
+    public static VehicleResponse fromVehicle(Vehicle vehicle) {
+        return new VehicleResponse(
+                vehicle.id(),
+                vehicle.brand(),
+                vehicle.model(),
+                vehicle.licensePlate(),
+                vehicle.year(),
+                vehicle.capacityKg(),
+                vehicle.status()
+        );
+    }
+
+    public Vehicle toVehicle() {
+        return new Vehicle(
+                this.id(),
+                this.brand(),
+                this.model(),
+                this.licensePlate(),
+                this.year(),
+                this.capacityKg(),
+                this.status()
+        );
+    }
+}

src/main/java/ua/com/dxrkness/exception/FreightNotFoundException.java

@@ -0,0 +1,7 @@
+package ua.com.dxrkness.exception;
+
+public class FreightNotFoundException extends RuntimeException {
+    public FreightNotFoundException(String message) {
+        super(message);
+    }
+}

src/main/java/ua/com/dxrkness/exception/RouteNotFoundException.java

@@ -0,0 +1,7 @@
+package ua.com.dxrkness.exception;
+
+public class RouteNotFoundException extends RuntimeException {
+    public RouteNotFoundException(String message) {
+        super(message);
+    }
+}

src/main/java/ua/com/dxrkness/exception/VehicleNotFoundException.java

@@ -0,0 +1,7 @@
+package ua.com.dxrkness.exception;
+
+public class VehicleNotFoundException extends RuntimeException {
+    public VehicleNotFoundException(String message) {
+        super(message);
+    }
+}

src/main/java/ua/com/dxrkness/model/Freight.java

@@ -1,15 +1,19 @@
 package ua.com.dxrkness.model;
 
-import tools.jackson.databind.PropertyNamingStrategies;
-import tools.jackson.databind.annotation.JsonNaming;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
 
 @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
 public record Freight(long id,
                       String name,
                       String description,
                       int weightKg,
                       Dimensions dimensions,
                       Status status) implements Identifiable {
+    @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+    @tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
     public record Dimensions(int widthCm,
                              int heightCm,
                              int lengthCm) {

src/main/java/ua/com/dxrkness/model/Route.java

@@ -1,11 +1,13 @@
 package ua.com.dxrkness.model;
 
-import tools.jackson.databind.PropertyNamingStrategies;
-import tools.jackson.databind.annotation.JsonNaming;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
 
 import java.util.List;
 
 @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
 public record Route(long id,
                     long vehicleId,
                     List<Long> freightId,

src/main/java/ua/com/dxrkness/model/Vehicle.java

@@ -1,9 +1,10 @@
 package ua.com.dxrkness.model;
 
-import tools.jackson.databind.PropertyNamingStrategies;
-import tools.jackson.databind.annotation.JsonNaming;
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
 
 @JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+@tools.jackson.databind.annotation.JsonNaming(tools.jackson.databind.PropertyNamingStrategies.SnakeCaseStrategy.class)
 public record Vehicle(long id,
                       String brand,
                       String model,

src/main/java/ua/com/dxrkness/service/FreightService.java

@@ -2,6 +2,9 @@ package ua.com.dxrkness.service;
 
 import org.jspecify.annotations.Nullable;
 import org.springframework.stereotype.Service;
+import ua.com.dxrkness.dto.FreightRequest;
+import ua.com.dxrkness.dto.FreightResponse;
+import ua.com.dxrkness.exception.FreightNotFoundException;
 import ua.com.dxrkness.model.Freight;
 import ua.com.dxrkness.repository.FreightRepository;
 
@@ -15,25 +18,40 @@ public final class FreightService {
         this.repo = repo;
     }
 
-    public List<Freight> getAll() {
-        return repo.getAll();
+    public List<FreightResponse> getAll() {
+        return repo.getAll().stream().map(FreightResponse::fromEntity).toList();
     }
 
-    public Freight add(Freight freight) {
-        int id = repo.add(freight);
-        return new Freight(id, freight.name(), freight.description(), freight.weightKg(), freight.dimensions(), freight.status());
+    public FreightResponse add(FreightRequest freight) {
+        int id = repo.add(freight.toEntity());
+        return FreightResponse.fromEntity(new Freight(id, freight.name(), freight.description(), freight.weightKg(), freight.dimensions(), freight.status()));
     }
 
-    public @Nullable Freight getById(long id) {
-        return repo.getById(id);
+    public FreightResponse getById(long id) {
+        Freight freight = repo.getById(id);
+        if (freight == null) {
+            throw new FreightNotFoundException("Freight with ID " + id + " not found.");
+        }
+        return FreightResponse.fromEntity(freight);
     }
 
-    public Freight update(long id, Freight newFreight) {
-        newFreight = new Freight(id, newFreight.name(), newFreight.description(), newFreight.weightKg(), newFreight.dimensions(), newFreight.status());
-        return repo.update(id, newFreight);
+    public List<FreightResponse> getByStatus(Freight.Status status) {
+        return repo.getAll().stream()
+                .filter(f -> f.status() == status)
+                .map(FreightResponse::fromEntity)
+                .toList();
     }
 
-    public @Nullable Freight delete(long id) {
-        return repo.delete(id);
+    public FreightResponse update(long id, FreightRequest newFreight) {
+        var newFreightEntity = new Freight(id, newFreight.name(), newFreight.description(), newFreight.weightKg(), newFreight.dimensions(), newFreight.status());
+        return FreightResponse.fromEntity(repo.update(id, newFreightEntity));
+    }
+
+    public FreightResponse delete(long id) {
+        var deleted = repo.delete(id);
+        if (deleted == null) {
+            throw new FreightNotFoundException("Freight with ID " + id + " not found.");
+        }
+        return FreightResponse.fromEntity(deleted);
     }
 }

src/main/java/ua/com/dxrkness/service/RouteService.java

@@ -2,6 +2,13 @@ package ua.com.dxrkness.service;
 
 import org.jspecify.annotations.Nullable;
 import org.springframework.stereotype.Service;
+import ua.com.dxrkness.dto.FreightDto;
+import ua.com.dxrkness.dto.RouteRequest;
+import ua.com.dxrkness.dto.RouteResponse;
+import ua.com.dxrkness.dto.VehicleDto;
+import ua.com.dxrkness.exception.FreightNotFoundException;
+import ua.com.dxrkness.exception.RouteNotFoundException;
+import ua.com.dxrkness.exception.VehicleNotFoundException;
 import ua.com.dxrkness.model.Route;
 import ua.com.dxrkness.repository.RouteRepository;
 
@@ -10,41 +17,88 @@ import java.util.List;
 @Service
 public final class RouteService {
     private final RouteRepository repo;
+    private final VehicleService vehicleService;
+    private final FreightService freightService;
 
-    public RouteService(RouteRepository repo) {
+    public RouteService(RouteRepository repo,
+                        VehicleService vehicleService,
+                        FreightService freightService) {
         this.repo = repo;
+        this.vehicleService = vehicleService;
+        this.freightService = freightService;
     }
 
-    public List<Route> getAll() {
-        return repo.getAll();
+    public List<RouteResponse> getAll() {
+        return repo.getAll().stream().map(RouteResponse::fromRoute).toList();
     }
 
-    public @Nullable Route getById(long id) {
-        return repo.getById(id);
+    public RouteResponse getById(long id) {
+        Route route = repo.getById(id);
+        if (route == null) {
+            throw new RouteNotFoundException("Route with ID " + id + " not found.");
+        }
+        return RouteResponse.fromRoute(route);
     }
 
-    public Route add(Route route) {
-        int id = repo.add(route);
-        return new Route(id,
+    public RouteResponse add(RouteRequest route) {
+        VehicleDto vehicleDto = validateAndGetVehicle(route.vehicleId());
+        List<FreightDto> freightDtos = validateAndGetFreights(route.freightId());
+        
+        int id = repo.add(route.toEntity());
+        return RouteResponse.fromRoute(new Route(id,
                 route.vehicleId(),
                 route.freightId(),
                 route.startLocation(),
                 route.endLocation(),
                 route.distanceKm(),
                 route.estimatedDurationHours(),
-                route.status());
+                route.status()));
     }
 
-    public @Nullable Route getByFreightId(long freightId) {
-        return repo.getByFreightId(freightId);
+    private VehicleDto validateAndGetVehicle(long vehicleId) {
+        try {
+            var vehicle = vehicleService.getById(vehicleId);
+            return VehicleDto.fromResponse(vehicle);
+        } catch (VehicleNotFoundException e) {
+            throw new VehicleNotFoundException(
+                    "Cannot create or update route: Referenced vehicle with ID " + vehicleId + " not found.");
+        }
     }
 
-    public List<Route> getByVehicleId(long vehicleId) {
-        return repo.getByVehicleId(vehicleId);
+    private List<FreightDto> validateAndGetFreights(List<Long> freightIds) {
+        List<FreightDto> freightDtos = new java.util.ArrayList<>();
+        for (long freightId : freightIds) {
+            try {
+                var freight = freightService.getById(freightId);
+                freightDtos.add(FreightDto.fromResponse(freight));
+            } catch (FreightNotFoundException e) {
+                throw new FreightNotFoundException(
+                        "Cannot create or update route: Referenced freight with ID " + freightId + " not found.");
+            }
+        }
+        return freightDtos;
     }
 
-    public Route update(long id, Route newRoute) {
-        newRoute = new Route(id,
+    public @Nullable RouteResponse getByFreightId(long freightId) {
+        return RouteResponse.fromRoute(repo.getByFreightId(freightId));
+    }
+
+    public List<RouteResponse> getByVehicleId(long vehicleId) {
+        return repo.getByVehicleId(vehicleId).stream().map(RouteResponse::fromRoute).toList();
+    }
+
+    public List<RouteResponse> getByStatus(Route.Status status) {
+        return repo.getAll().stream()
+                .filter(r -> r.status() == status)
+                .map(RouteResponse::fromRoute)
+                .toList();
+    }
+
+    public RouteResponse update(long id, RouteRequest newRoute) {
+        VehicleDto vehicleDto = validateAndGetVehicle(newRoute.vehicleId());
+        List<FreightDto> freightDtos = validateAndGetFreights(newRoute.freightId());
+        
+        var newRouteEntity = new Route(id,
                 newRoute.vehicleId(),
                 newRoute.freightId(),
                 newRoute.startLocation(),
@@ -52,10 +106,14 @@ public final class RouteService {
                 newRoute.distanceKm(),
                 newRoute.estimatedDurationHours(),
                 newRoute.status());
-        return repo.update(id, newRoute);
+        return RouteResponse.fromRoute(repo.update(id, newRouteEntity));
     }
 
-    public @Nullable Route delete(long id) {
-        return repo.delete(id);
+    public RouteResponse delete(long id) {
+        var deleted = repo.delete(id);
+        if (deleted == null) {
+            throw new RouteNotFoundException("Route with ID " + id + " not found.");
+        }
+        return RouteResponse.fromRoute(deleted);
     }
 }

src/main/java/ua/com/dxrkness/service/VehicleService.java

@@ -1,7 +1,9 @@
 package ua.com.dxrkness.service;
 
-import org.jspecify.annotations.Nullable;
 import org.springframework.stereotype.Service;
+import ua.com.dxrkness.dto.VehicleRequest;
+import ua.com.dxrkness.dto.VehicleResponse;
+import ua.com.dxrkness.exception.VehicleNotFoundException;
 import ua.com.dxrkness.model.Vehicle;
 import ua.com.dxrkness.repository.VehicleRepository;
 
@@ -15,31 +17,46 @@ public final class VehicleService {
         this.repo = repo;
     }
 
-    public List<Vehicle> getAll() {
-        return repo.getAll();
+    public List<VehicleResponse> getAll() {
+        return repo.getAll().stream().map(VehicleResponse::fromVehicle).toList();
     }
 
-    public Vehicle add(Vehicle veh) {
-        int id = repo.add(veh);
-        return new Vehicle(id, veh.brand(), veh.model(), veh.licensePlate(), veh.year(), veh.capacityKg(), veh.status());
+    public List<VehicleResponse> getByStatus(Vehicle.Status status) {
+        return repo.getAll().stream()
+                .filter(v -> v.status() == status)
+                .map(VehicleResponse::fromVehicle)
+                .toList();
     }
 
-    public @Nullable Vehicle getById(long id) {
-        return repo.getById(id);
+    public VehicleResponse add(VehicleRequest veh) {
+        int id = repo.add(veh.toEntity());
+        return new VehicleResponse(id, veh.brand(), veh.model(), veh.licensePlate(), veh.year(), veh.capacityKg(), veh.status());
     }
 
-    public Vehicle update(long id, Vehicle newVehicle) {
-        newVehicle = new Vehicle(id,
+    public VehicleResponse getById(long id) {
+        Vehicle vehicle = repo.getById(id);
+        if (vehicle == null) {
+            throw new VehicleNotFoundException("Vehicle with ID " + id + " not found.");
+        }
+        return VehicleResponse.fromVehicle(vehicle);
+    }
+
+    public VehicleResponse update(long id, VehicleRequest newVehicle) {
+        var newVehicleEntity = new Vehicle(id,
                 newVehicle.brand(),
                 newVehicle.model(),
                 newVehicle.licensePlate(),
                 newVehicle.year(),
                 newVehicle.capacityKg(),
                 newVehicle.status());
-        return repo.update(id, newVehicle);
+        return VehicleResponse.fromVehicle(repo.update(id, newVehicleEntity));
     }
 
-    public @Nullable Vehicle delete(long id) {
-        return repo.delete(id);
+    public VehicleResponse delete(long id) {
+        var deleted = repo.delete(id);
+        if (deleted == null) {
+            throw new VehicleNotFoundException("Vehicle with ID " + id + " not found.");
+        }
+        return VehicleResponse.fromVehicle(deleted);
     }
 }

src/test/java/ua/com/dxrkness/integration/InterServiceCommunicationTest.java

@@ -0,0 +1,198 @@
+package ua.com.dxrkness.integration;
+
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.client.RestTestClient;
+import org.springframework.web.context.WebApplicationContext;
+import ua.com.dxrkness.model.Route;
+import ua.com.dxrkness.service.PopulateService;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.BDDAssertions.then;
+
+@SpringBootTest
+@NullMarked
+class InterServiceCommunicationTest {
+    private static final int AMOUNT = 100;
+    @Autowired
+    private PopulateService populateService;
+
+    private RestTestClient routesClient;
+    private RestTestClient vehiclesClient;
+    private RestTestClient freightsClient;
+
+    @BeforeEach
+    void setUp(WebApplicationContext context) {
+        populateService.populate(AMOUNT);
+        routesClient = RestTestClient.bindToApplicationContext(context).baseUrl("/routes").build();
+        vehiclesClient = RestTestClient.bindToApplicationContext(context).baseUrl("/vehicles").build();
+        freightsClient = RestTestClient.bindToApplicationContext(context).baseUrl("/freights").build();
+    }
+
+    @AfterEach
+    void teardown() {
+        populateService.clear();
+    }
+
+    private static Stream<MediaType> mediaTypes() {
+        return Stream.of(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML);
+    }
+
+    // ===== INTER-SERVICE VALIDATION TESTS =====
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void createRoute_WithValidVehicleAndFreights_Succeeds(MediaType mediaType) {
+        // given - a route with valid vehicle and freight references
+        final var validVehicleId = 1;
+        final var validFreightIds = List.of(1L, 2L);
+        final var newRoute = new Route(0, validVehicleId, validFreightIds, 
+                "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+
+        // when - creating the route
+        // then - should succeed because vehicle and freights exist (validated through inter-service communication)
+        routesClient.post()
+                .accept(mediaType)
+                .contentType(mediaType)
+                .body(newRoute)
+                .exchange()
+                .expectStatus()
+                .isOk();
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void createRoute_WithInvalidVehicleId_Returns404(MediaType mediaType) {
+        // given - a route with an invalid (non-existent) vehicle ID
+        final var invalidVehicleId = -1;
+        final var validFreightIds = List.of(1L);
+        final var newRoute = new Route(0, invalidVehicleId, validFreightIds,
+                "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+
+        // when - creating the route
+        // then - should fail with 404 because vehicle doesn't exist (inter-service validation)
+        routesClient.post()
+                .accept(mediaType)
+                .contentType(mediaType)
+                .body(newRoute)
+                .exchange()
+                .expectStatus()
+                .isNotFound()
+                .expectBody(String.class)
+                .consumeWith(res -> {
+                    String body = res.getResponseBody();
+                    then(body).isNotNull();
+                    then(body).contains("Not Found").contains("vehicle");
+                });
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void createRoute_WithInvalidFreightId_Returns404(MediaType mediaType) {
+        // given - a route with a valid vehicle but invalid freight ID
+        final var validVehicleId = 1;
+        final var invalidFreightIds = List.of(-1L);  // Invalid freight ID
+        final var newRoute = new Route(0, validVehicleId, invalidFreightIds,
+                "Kyiv", "Lviv", 540.0, 8.5, Route.Status.PLANNED);
+
+        // when - creating the route
+        // then - should fail with 404 because freight doesn't exist (inter-service validation)
+        routesClient.post()
+                .accept(mediaType)
+                .contentType(mediaType)
+                .body(newRoute)
+                .exchange()
+                .expectStatus()
+                .isNotFound()
+                .expectBody(String.class)
+                .consumeWith(res -> {
+                    String body = res.getResponseBody();
+                    then(body).isNotNull();
+                    then(body).contains("Not Found").contains("freight");
+                });
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void updateRoute_ValidatesReferences_OnInterServiceCall(MediaType mediaType) {
+        // given - an existing route and new valid references
+        final var routeId = 1;
+        final var validVehicleId = 2;
+        final var validFreightIds = List.of(3L, 4L);
+        final var updatedRoute = new Route(routeId, validVehicleId, validFreightIds,
+                "Odesa", "Kharkiv", 700.0, 10.0, Route.Status.IN_PROGRESS);
+
+        // when - updating the route
+        // then - should succeed because vehicle and freights exist (inter-service validation)
+        routesClient.put().uri("/{id}", routeId)
+                .accept(mediaType)
+                .contentType(mediaType)
+                .body(updatedRoute)
+                .exchange()
+                .expectStatus()
+                .isOk();
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void updateRoute_WithInvalidVehicleOnUpdate_Returns404(MediaType mediaType) {
+        // given - an existing route and new references with invalid vehicle
+        final var routeId = 1;
+        final var invalidVehicleId = -999;
+        final var validFreightIds = List.of(3L);
+        final var updatedRoute = new Route(routeId, invalidVehicleId, validFreightIds,
+                "Odesa", "Kharkiv", 700.0, 10.0, Route.Status.IN_PROGRESS);
+
+        // when - updating the route
+        // then - should fail with 404 (inter-service validation on update)
+        routesClient.put().uri("/{id}", routeId)
+                .accept(mediaType)
+                .contentType(mediaType)
+                .body(updatedRoute)
+                .exchange()
+                .expectStatus()
+                .isNotFound();
+    }
+
+    // ===== VEHICLE INTER-SERVICE TESTS =====
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void getVehicle_UsedInRoute_ReturnsVehicleData(MediaType mediaType) {
+        // given - a vehicle that is used in routes
+        final var vehicleId = 1;
+
+        // when - retrieving the vehicle
+        // then - should return vehicle data (VehicleService provides data to other services)
+        vehiclesClient.get().uri("/{id}", vehicleId)
+                .accept(mediaType)
+                .exchange()
+                .expectStatus()
+                .isOk();
+    }
+
+    // ===== FREIGHT INTER-SERVICE TESTS =====
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void getFreight_UsedInRoute_ReturnsFreightData(MediaType mediaType) {
+        // given - a freight that is used in routes
+        final var freightId = 1;
+
+        // when - retrieving the freight
+        // then - should return freight data (FreightService provides data to other services)
+        freightsClient.get().uri("/{id}", freightId)
+                .accept(mediaType)
+                .exchange()
+                .expectStatus()
+                .isOk();
+    }
+}

src/test/java/ua/com/dxrkness/integration/SubResourcesAndFilteringTest.java

@@ -0,0 +1,113 @@
+package ua.com.dxrkness.integration;
+
+import org.jspecify.annotations.NullMarked;
+import org.junit.jupiter.api.AfterEach;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.params.ParameterizedTest;
+import org.junit.jupiter.params.provider.MethodSource;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.core.ParameterizedTypeReference;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.client.RestTestClient;
+import org.springframework.web.context.WebApplicationContext;
+import ua.com.dxrkness.model.Freight;
+import ua.com.dxrkness.model.Route;
+import ua.com.dxrkness.service.PopulateService;
+
+import java.util.List;
+import java.util.stream.Stream;
+
+import static org.assertj.core.api.BDDAssertions.then;
+
+@SpringBootTest
+@NullMarked
+class SubResourcesAndFilteringTest {
+    private static final int AMOUNT = 100;
+    @Autowired
+    private PopulateService populateService;
+
+    private RestTestClient vehiclesClient;
+    private RestTestClient routesClient;
+    private RestTestClient freightsClient;
+
+    @BeforeEach
+    void setUp(WebApplicationContext context) {
+        populateService.populate(AMOUNT);
+        vehiclesClient = RestTestClient.bindToApplicationContext(context).baseUrl("/vehicles").build();
+        routesClient = RestTestClient.bindToApplicationContext(context).baseUrl("/routes").build();
+        freightsClient = RestTestClient.bindToApplicationContext(context).baseUrl("/freights").build();
+    }
+
+    @AfterEach
+    void teardown() {
+        populateService.clear();
+    }
+
+    private static Stream<MediaType> mediaTypes() {
+        return Stream.of(MediaType.APPLICATION_JSON, MediaType.APPLICATION_XML);
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void getById_VehicleNotFound_Returns404WithErrorResponse(MediaType mediaType) {
+        // given
+        final var vehicleId = -1;
+
+        // when
+        // then
+        vehiclesClient.get().uri("/{id}", vehicleId)
+                .accept(mediaType)
+                .exchange()
+                .expectStatus()
+                .isNotFound()
+                .expectBody(String.class)
+                .consumeWith(res -> {
+                    String body = res.getResponseBody();
+                    then(body).isNotNull();
+                    then(body).contains("Not Found");
+                });
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void getById_RouteNotFound_Returns404WithErrorResponse(MediaType mediaType) {
+        // given
+        final var routeId = -1;
+
+        // when
+        // then
+        routesClient.get().uri("/{id}", routeId)
+                .accept(mediaType)
+                .exchange()
+                .expectStatus()
+                .isNotFound()
+                .expectBody(String.class)
+                .consumeWith(res -> {
+                    String body = res.getResponseBody();
+                    then(body).isNotNull();
+                    then(body).contains("Not Found");
+                });
+    }
+
+    @ParameterizedTest
+    @MethodSource("mediaTypes")
+    void getById_FreightNotFound_Returns404WithErrorResponse(MediaType mediaType) {
+        // given
+        final var freightId = -1;
+
+        // when
+        // then
+        freightsClient.get().uri("/{id}", freightId)
+                .accept(mediaType)
+                .exchange()
+                .expectStatus()
+                .isNotFound()
+                .expectBody(String.class)
+                .consumeWith(res -> {
+                    String body = res.getResponseBody();
+                    then(body).isNotNull();
+                    then(body).contains("Not Found");
+                });
+    }
+}