Done

src/main/java/de/szut/lf8_starter/employee/EmployeeService.java

@@ -0,0 +1,34 @@
+package de.szut.lf8_starter.employee;
+
+import org.springframework.http.HttpEntity;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.HttpMethod;
+import org.springframework.stereotype.Service;
+import org.springframework.web.client.HttpClientErrorException;
+import org.springframework.web.client.RestTemplate;
+
+@Service
+public class EmployeeService {
+    private final RestTemplate restTemplate;
+
+    public EmployeeService(RestTemplate restTemplate) {
+        this.restTemplate = restTemplate;
+    }
+
+    public boolean employeeExists(String accessToken, Long employeeId) {
+        HttpHeaders headers = new HttpHeaders();
+        headers.setBearerAuth(accessToken.replace("Bearer ", ""));
+
+        HttpEntity<String> requestEntity = new HttpEntity<>(headers);
+
+        String url = "https://employee.szut.dev/employees/" + employeeId;
+
+        try {
+            restTemplate.exchange(url, HttpMethod.GET, requestEntity, String.class);
+        } catch (HttpClientErrorException.NotFound e) {
+            return false;
+        }
+
+        return true;
+    }
+}

src/main/java/de/szut/lf8_starter/project/ProjectService.java

@@ -25,10 +25,8 @@ public class ProjectService {
         return projectRepository.findById(id);
     }
 
-    public ProjectEntity update(ProjectEntity project) {
+    public void update(ProjectEntity project) {
         this.projectRepository.save(project);
-
-        return project;
     }
 
     public void delete(Long id) {

src/main/java/de/szut/lf8_starter/project/action/employee/AddEmployeeToProjectAction.java

@@ -1,27 +1,36 @@
 package de.szut.lf8_starter.project.action.employee;
 
+import de.szut.lf8_starter.employee.EmployeeService;
 import de.szut.lf8_starter.project.ProjectEntity;
 import de.szut.lf8_starter.project.ProjectService;
-import org.springframework.http.*;
+import io.swagger.v3.oas.annotations.Operation;
+import io.swagger.v3.oas.annotations.media.Content;
+import io.swagger.v3.oas.annotations.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.web.bind.annotation.PathVariable;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestHeader;
 import org.springframework.web.bind.annotation.RestController;
-import org.springframework.web.client.RestTemplate;
 
 import java.util.Optional;
 
 @RestController
 public class AddEmployeeToProjectAction {
     private final ProjectService projectService;
-    private final RestTemplate restTemplate;
+    private final EmployeeService employeeService;
 
-    public AddEmployeeToProjectAction(ProjectService projectService, RestTemplate restTemplate) {
+    public AddEmployeeToProjectAction(ProjectService projectService, EmployeeService employeeService) {
         this.projectService = projectService;
-        this.restTemplate = restTemplate;
+        this.employeeService = employeeService;
     }
 
-
+    @Operation(summary = "Add an employee to a project")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "204", description = "Employee added to project"),
+            @ApiResponse(responseCode = "404", description = "Project or employee not found", content = @Content)
+    })
     @PostMapping("/projects/{projectId}/employees/{employeeId}")
     public ResponseEntity<Object> create(
             @PathVariable Long projectId,
@@ -34,15 +43,12 @@ public class AddEmployeeToProjectAction {
             return new ResponseEntity<>(HttpStatus.NOT_FOUND);
         }
 
-        HttpHeaders headers = new HttpHeaders();
-        headers.setBearerAuth(accessToken.replace("Bearer ", ""));
+        if (!this.employeeService.employeeExists(accessToken, employeeId)) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
 
-        HttpEntity<String> requestEntity = new HttpEntity<>(headers);
-
-        String url = "https://employee.szut.dev/employees/" + employeeId;
-        ResponseEntity<String> response = restTemplate.exchange(url, HttpMethod.GET, requestEntity, String.class);
-
-        System.out.println("Employee Data: " + response.getBody());
+        project.get().getEmployees().add(employeeId);
+        this.projectService.update(project.get());
 
         return new ResponseEntity<>(HttpStatus.NO_CONTENT);
     }

src/main/java/de/szut/lf8_starter/project/dto/EmployeeDto.java

@@ -1,15 +1,22 @@
 package de.szut.lf8_starter.project.dto;
 
-import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
 import com.fasterxml.jackson.databind.PropertyNamingStrategies;
 import com.fasterxml.jackson.databind.annotation.JsonNaming;
 import lombok.Getter;
 import lombok.Setter;
 
-@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
-@JsonIgnoreProperties(ignoreUnknown = true)
+import java.util.List;
+
 @Getter
 @Setter
-public class BearerTokenResponseDto {
-    private String accessToken;
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public class EmployeeDto {
+    private long id;
+    private String firstName;
+    private String lastName;
+    private String street;
+    private String postcode;
+    private String city;
+    private String phone;
+    private List<String> skillSet;
 }

src/test/java/de/szut/lf8_starter/integration/project/AddEmployeeToProjectTest.java

@@ -0,0 +1,83 @@
+package de.szut.lf8_starter.integration.project;
+
+import de.szut.lf8_starter.employee.EmployeeService;
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectService;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.boot.test.mock.mockito.MockBean;
+import org.springframework.http.HttpHeaders;
+import org.springframework.http.MediaType;
+import org.springframework.test.web.servlet.MockMvc;
+
+import java.util.Optional;
+
+import static org.mockito.Mockito.when;
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc(addFilters = false)
+class AddEmployeeToProjectActionIntegrationTest {
+
+    @Autowired
+    private MockMvc mockMvc;
+
+    @MockBean
+    private ProjectService projectService;
+
+    @MockBean
+    private EmployeeService employeeService;
+
+    @Test
+    void testAddEmployeeToProject() throws Exception {
+        Long projectId = 1L;
+        Long employeeId = 1L;
+        String accessToken = "Bearer valid_token";
+
+        ProjectEntity projectEntity = new ProjectEntity();
+        projectEntity.setId(projectId);
+
+        when(projectService.findById(projectId)).thenReturn(Optional.of(projectEntity));
+        when(employeeService.employeeExists(accessToken, employeeId)).thenReturn(true);
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", projectId, employeeId)
+                        .header(HttpHeaders.AUTHORIZATION, accessToken)
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNoContent());
+    }
+
+    @Test
+    void testAddEmployeeToProject_ProjectNotFound() throws Exception {
+        Long projectId = 1L;
+        Long employeeId = 1L;
+        String accessToken = "Bearer valid_token";
+
+        when(projectService.findById(projectId)).thenReturn(Optional.empty());
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", projectId, employeeId)
+                        .header(HttpHeaders.AUTHORIZATION, accessToken)
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNotFound());
+    }
+
+    @Test
+    void testAddEmployeeToProject_EmployeeNotFound() throws Exception {
+        Long projectId = 1L;
+        Long employeeId = 1L;
+        String accessToken = "Bearer valid_token";
+
+        ProjectEntity projectEntity = new ProjectEntity();
+        projectEntity.setId(projectId);
+
+        when(projectService.findById(projectId)).thenReturn(Optional.of(projectEntity));
+        when(employeeService.employeeExists(accessToken, employeeId)).thenReturn(false);
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", projectId, employeeId)
+                        .header(HttpHeaders.AUTHORIZATION, accessToken)
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNotFound());
+    }
+}