feat: Implement feature to acknowledge project time frames when assigning employees to projects (SCRUM-7 SCRUM-2) (!38)

Co-authored-by: Phan Huy Tran <p.tran@neusta.de>
Reviewed-on: #38
Co-authored-by: Phan Huy Tran <ptran@noreply.localhost>
Co-committed-by: Phan Huy Tran <ptran@noreply.localhost>

requests/employee/createEmployee.http

@@ -0,0 +1,15 @@
+POST https://employee.szut.dev/employees
+Authorization: Bearer {{auth_token}}
+Content-Type: application/json
+
+{
+  "firstName": "Jan1",
+  "lastName": "Klattenhoff1",
+  "street": "Pirolweg 171",
+  "postcode": "27777",
+  "city": "Gandakersee1",
+  "phone": "0176849848161",
+  "skillSet": [
+    "1"
+  ]
+}

requests/employee/deleteEmployee.http

@@ -0,0 +1,2 @@
+DELETE https://employee.szut.dev/employees/310
+Authorization: Bearer {{auth_token}}

requests/employee/getAllEmployees.http

@@ -0,0 +1,2 @@
+GET https://employee.szut.dev/employees
+Authorization: Bearer {{auth_token}}

requests/employee/getEmployee.http

@@ -0,0 +1,2 @@
+GET https://employee.szut.dev/employees/315
+Authorization: Bearer {{auth_token}}

requests/employee/getProjects.http

@@ -0,0 +1,3 @@
+GET http://localhost:8080/employees/315/projects
+Authorization: Bearer {{auth_token}}
+Content-Type: application/json

requests/project/addEmployeeToProject.http

@@ -0,0 +1,2 @@
+POST http://localhost:8080/projects/1/employees/312
+Authorization: Bearer {{auth_token}}

requests/project/createProject.http

@@ -6,10 +6,10 @@ Content-Type: application/json
 {
   "name": "name",
   "leading_employee": 1,
-  "employees": [2, 3],
+  "employees": [312],
   "contractor": 4,
   "contractor_name": "Peter File",
   "comment": "goal of project",
-  "start_date": "01.01.2000",
+  "start_date": "02.01.2020",
-  "planned_end_date": "01.01.2001"
+  "planned_end_date": "01.01.2023"
 }

requests/project/getEmployeesFromProject.http

@@ -0,0 +1,2 @@
+GET http://localhost:8080/projects/2/employees
+Authorization: Bearer {{auth_token}}

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

@@ -0,0 +1,73 @@
+package de.szut.lf8_starter.employee;
+
+import de.szut.lf8_starter.exceptionHandling.ResourceNotFoundException;
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectRepository;
+import de.szut.lf8_starter.project.dto.employee.GetEmployeeDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
+import de.szut.lf8_starter.project.mapper.ProjectMapper;
+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;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Service
+public class EmployeeService {
+    private final RestTemplate restTemplate;
+    private final ProjectRepository projectRepository;
+    private final ProjectMapper projectMapper;
+
+    public EmployeeService(RestTemplate restTemplate, ProjectRepository projectRepository, ProjectMapper projectMapper) {
+        this.restTemplate = restTemplate;
+        this.projectRepository = projectRepository;
+        this.projectMapper = projectMapper;
+    }
+
+    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;
+    }
+
+    public GetEmployeeDto getEmployee(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 {
+            return restTemplate.exchange(url, HttpMethod.GET, requestEntity, GetEmployeeDto.class).getBody();
+        } catch (HttpClientErrorException.NotFound e) {
+            throw new ResourceNotFoundException("Employee not found");
+        }
+    }
+
+    public List<GetProjectDto> getProjects(Long employeeId) {
+        ArrayList<ProjectEntity> projects = this.projectRepository.findAllByEmployeeId(employeeId);
+        ArrayList<GetProjectDto> projectDtos = new ArrayList<>();
+
+        for (ProjectEntity project : projects) {
+            projectDtos.add(this.projectMapper.mapToGetDto(project));
+        }
+
+        return projectDtos;
+    }
+}

src/main/java/de/szut/lf8_starter/hello/HelloController.java

@@ -14,9 +14,6 @@ import org.springframework.http.HttpStatus;
 import org.springframework.security.access.prepost.PreAuthorize;
 import org.springframework.web.bind.annotation.*;
 
-import java.util.List;
-import java.util.stream.Collectors;
-
 @RestController
 @RequestMapping(value = "hello")
 @PreAuthorize("hasAnyAuthority('user')")

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

@@ -25,7 +25,7 @@ public class ProjectEntity {
 
     private long leadingEmployee;
 
-    @ElementCollection
+    @ElementCollection(fetch = FetchType.EAGER)
     private List<Long> employees;
 
     private long contractor;

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

@@ -1,8 +1,14 @@
 package de.szut.lf8_starter.project;
 
 import org.springframework.data.jpa.repository.JpaRepository;
+import org.springframework.data.jpa.repository.Query;
+import org.springframework.data.repository.query.Param;
 import org.springframework.stereotype.Repository;
 
+import java.util.ArrayList;
+
 @Repository
 public interface ProjectRepository extends JpaRepository<ProjectEntity, Long> {
+    @Query("SELECT p FROM ProjectEntity p WHERE :employeeId MEMBER OF p.employees")
+    ArrayList<ProjectEntity> findAllByEmployeeId(@Param("employeeId") Long employeeId);
 }

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

@@ -1,5 +1,6 @@
 package de.szut.lf8_starter.project;
 
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
 import org.springframework.stereotype.Service;
 
 import java.util.List;
@@ -25,13 +26,25 @@ 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) {
         this.projectRepository.deleteById(id);
     }
+
+    public boolean isOverlapping(GetProjectDto getProjectDto, ProjectEntity existingProjectEntity) {
+        return isDateRangeOverlapping(getProjectDto, existingProjectEntity) || isDateEqual(getProjectDto, existingProjectEntity);
+    }
+
+    private boolean isDateRangeOverlapping(GetProjectDto getProjectDto, ProjectEntity existingProjectEntity) {
+        return getProjectDto.getStartDate().isBefore(existingProjectEntity.getPlannedEndDate())
+                && getProjectDto.getPlannedEndDate().isAfter(existingProjectEntity.getStartDate());
+    }
+
+    private boolean isDateEqual(GetProjectDto getProjectDto, ProjectEntity existingProjectEntity) {
+        return getProjectDto.getStartDate().isEqual(existingProjectEntity.getStartDate())
+                || getProjectDto.getPlannedEndDate().isEqual(existingProjectEntity.getPlannedEndDate());
+    }
 }

src/main/java/de/szut/lf8_starter/project/action/CreateProjectAction.java

@@ -1,42 +0,0 @@
-package de.szut.lf8_starter.project.action;
-
-import de.szut.lf8_starter.project.ProjectEntity;
-import de.szut.lf8_starter.project.ProjectMapper;
-import de.szut.lf8_starter.project.ProjectService;
-import de.szut.lf8_starter.project.dto.CreateProjectDto;
-import de.szut.lf8_starter.project.dto.GetProjectDto;
-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.responses.ApiResponse;
-import io.swagger.v3.oas.annotations.responses.ApiResponses;
-import jakarta.validation.Valid;
-import org.springframework.http.HttpStatus;
-import org.springframework.web.bind.annotation.*;
-
-@RestController
-@RequestMapping(value = "/projects")
-public class CreateProjectAction {
-    private final ProjectService projectService;
-    private final ProjectMapper projectMapper;
-
-    public CreateProjectAction(ProjectService projectService, ProjectMapper mappingService) {
-        this.projectService = projectService;
-        this.projectMapper = mappingService;
-    }
-
-    @Operation(summary = "Creates a new Project")
-    @ApiResponses(value = {
-            @ApiResponse(responseCode = "201", description = "created project", content = {@Content(mediaType = "application/json", schema = @Schema(implementation = GetProjectDto.class))}),
-            @ApiResponse(responseCode = "400", description = "invalid JSON posted", content = @Content),
-            @ApiResponse(responseCode = "401", description = "not authorized", content = @Content)})
-    @PostMapping
-    @ResponseStatus(code = HttpStatus.CREATED)
-    public GetProjectDto create(@RequestBody @Valid CreateProjectDto createProjectDto) {
-        ProjectEntity projectEntity = this.projectMapper.mapCreateDtoToEntity(createProjectDto);
-
-        projectEntity = this.projectService.create(projectEntity);
-
-        return this.projectMapper.mapToGetDto(projectEntity);
-    }
-}

src/main/java/de/szut/lf8_starter/project/action/crud/CreateProjectAction.java

@@ -0,0 +1,63 @@
+package de.szut.lf8_starter.project.action.crud;
+
+import de.szut.lf8_starter.employee.EmployeeService;
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectService;
+import de.szut.lf8_starter.project.dto.project.CreateProjectDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
+import de.szut.lf8_starter.project.mapper.ProjectMapper;
+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.responses.ApiResponse;
+import io.swagger.v3.oas.annotations.responses.ApiResponses;
+import jakarta.validation.Valid;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.*;
+
+@RestController
+@RequestMapping(value = "/projects")
+public class CreateProjectAction {
+    private final EmployeeService employeeService;
+    private final ProjectService projectService;
+    private final ProjectMapper projectMapper;
+
+    public CreateProjectAction(EmployeeService employeeService, ProjectService projectService, ProjectMapper mappingService) {
+        this.employeeService = employeeService;
+        this.projectService = projectService;
+        this.projectMapper = mappingService;
+    }
+
+    @Operation(summary = "Creates a new Project")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "201", description = "created project", content = {@Content(mediaType = "application/json", schema = @Schema(implementation = GetProjectDto.class))}),
+            @ApiResponse(responseCode = "400", description = "invalid JSON posted", content = @Content),
+            @ApiResponse(responseCode = "401", description = "not authorized", content = @Content),
+            @ApiResponse(responseCode = "409", description = "Project dates conflict", content = @Content)
+    })
+    @PostMapping
+    @ResponseStatus(code = HttpStatus.CREATED)
+    public ResponseEntity<Object> create(
+            @RequestBody @Valid CreateProjectDto createProjectDto,
+            @RequestHeader("Authorization") String accessToken
+    ) {
+        ProjectEntity project = this.projectMapper.mapCreateDtoToEntity(createProjectDto);
+
+        for (Long employeeId : createProjectDto.getEmployees()) {
+            if (!this.employeeService.employeeExists(accessToken, employeeId)) {
+                return new ResponseEntity<>("Employee with ID: " + employeeId + " not found", HttpStatus.NOT_FOUND);
+            }
+
+            for (GetProjectDto getProjectDto : this.employeeService.getProjects(employeeId)) {
+                if (projectService.isOverlapping(getProjectDto, project)) {
+                    return new ResponseEntity<>("Project dates conflict with an existing project for Employee with ID: " + employeeId, HttpStatus.CONFLICT);
+                }
+            }
+        }
+
+        this.projectService.create(project);
+
+        return new ResponseEntity<>(this.projectMapper.mapToGetDto(project), HttpStatus.CREATED);
+    }
+}

src/main/java/de/szut/lf8_starter/project/action/crud/GetAllProjectsAction.java

@@ -1,8 +1,8 @@
-package de.szut.lf8_starter.project.action;
+package de.szut.lf8_starter.project.action.crud;
 
-import de.szut.lf8_starter.project.ProjectMapper;
 import de.szut.lf8_starter.project.ProjectService;
-import de.szut.lf8_starter.project.dto.GetProjectDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
+import de.szut.lf8_starter.project.mapper.ProjectMapper;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;

src/main/java/de/szut/lf8_starter/project/action/crud/GetProjectAction.java

@@ -1,9 +1,9 @@
-package de.szut.lf8_starter.project.action;
+package de.szut.lf8_starter.project.action.crud;
 
 import de.szut.lf8_starter.project.ProjectEntity;
-import de.szut.lf8_starter.project.ProjectMapper;
 import de.szut.lf8_starter.project.ProjectService;
-import de.szut.lf8_starter.project.dto.GetProjectDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
+import de.szut.lf8_starter.project.mapper.ProjectMapper;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;
@@ -11,7 +11,10 @@ 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.*;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
 
 import java.util.Optional;
 

src/main/java/de/szut/lf8_starter/project/action/crud/RemoveProjectAction.java

@@ -1,15 +1,18 @@
-package de.szut.lf8_starter.project.action;
+package de.szut.lf8_starter.project.action.crud;
 
 import de.szut.lf8_starter.project.ProjectEntity;
 import de.szut.lf8_starter.project.ProjectService;
-import de.szut.lf8_starter.project.dto.GetProjectDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
 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.*;
+import org.springframework.web.bind.annotation.DeleteMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
 
 import java.util.Optional;
 

src/main/java/de/szut/lf8_starter/project/action/crud/UpdateProjectAction.java

@@ -1,10 +1,10 @@
-package de.szut.lf8_starter.project.action;
+package de.szut.lf8_starter.project.action.crud;
 
 import de.szut.lf8_starter.project.ProjectEntity;
-import de.szut.lf8_starter.project.ProjectMapper;
 import de.szut.lf8_starter.project.ProjectService;
-import de.szut.lf8_starter.project.dto.GetProjectDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
-import de.szut.lf8_starter.project.dto.UpdateProjectDto;
+import de.szut.lf8_starter.project.dto.project.UpdateProjectDto;
+import de.szut.lf8_starter.project.mapper.ProjectMapper;
 import io.swagger.v3.oas.annotations.Operation;
 import io.swagger.v3.oas.annotations.media.Content;
 import io.swagger.v3.oas.annotations.media.Schema;

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

@@ -0,0 +1,65 @@
+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 de.szut.lf8_starter.project.dto.project.GetProjectDto;
+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 java.util.Optional;
+
+@RestController
+public class AddEmployeeToProjectAction {
+    private final ProjectService projectService;
+    private final EmployeeService employeeService;
+
+    public AddEmployeeToProjectAction(ProjectService projectService, EmployeeService employeeService) {
+        this.projectService = projectService;
+        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),
+            @ApiResponse(responseCode = "409", description = "Project dates conflict", content = @Content)
+    })
+    @PostMapping("/projects/{projectId}/employees/{employeeId}")
+    public ResponseEntity<Object> create(
+            @PathVariable Long projectId,
+            @PathVariable Long employeeId,
+            @RequestHeader("Authorization") String accessToken
+    ) {
+        Optional<ProjectEntity> optionalProject = this.projectService.findById(projectId);
+
+        if (optionalProject.isEmpty()) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        ProjectEntity projectEntity = optionalProject.get();
+
+        if (!this.employeeService.employeeExists(accessToken, employeeId)) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        for (GetProjectDto getProjectDto : this.employeeService.getProjects(employeeId)) {
+            if (this.projectService.isOverlapping(getProjectDto, projectEntity)) {
+                return new ResponseEntity<>("Project dates conflict with an existing project for Employee with ID: " + employeeId, HttpStatus.CONFLICT);
+            }
+        }
+
+        projectEntity.getEmployees().add(employeeId);
+        this.projectService.update(projectEntity);
+
+        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
+    }
+}

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

@@ -0,0 +1,51 @@
+package de.szut.lf8_starter.project.action.employee;
+
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectService;
+import de.szut.lf8_starter.project.dto.employee.GetEmployeesFromProjectDto;
+import de.szut.lf8_starter.project.mapper.EmployeeFromProjectMapper;
+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.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.Optional;
+
+@RestController
+public class GetEmployeeFromProjectAction {
+    private final ProjectService projectService;
+    private final EmployeeFromProjectMapper employeeFromProjectMapper;
+
+    public GetEmployeeFromProjectAction(ProjectService projectService, EmployeeFromProjectMapper employeeFromProjectMapper) {
+        this.projectService = projectService;
+        this.employeeFromProjectMapper = employeeFromProjectMapper;
+    }
+
+    @Operation(summary = "Get all employees from project")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Outputs projects with employees"),
+            @ApiResponse(responseCode = "404", description = "Project not found", content = @Content)
+    })
+    @GetMapping("/projects/{projectId}/employees")
+    public ResponseEntity<Object> create(
+            @PathVariable Long projectId,
+            @RequestHeader("Authorization") String accessToken
+    ) {
+        Optional<ProjectEntity> project = projectService.findById(projectId);
+
+        if (project.isEmpty()) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        GetEmployeesFromProjectDto getEmployeesFromProjectDto = this.employeeFromProjectMapper
+                .mapToGetEmployeesFromProjectDto(project.get(), accessToken);
+
+        return new ResponseEntity<>(getEmployeesFromProjectDto, HttpStatus.OK);
+    }
+}

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

@@ -0,0 +1,39 @@
+package de.szut.lf8_starter.project.action.employee;
+
+import de.szut.lf8_starter.employee.EmployeeService;
+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.GetMapping;
+import org.springframework.web.bind.annotation.PathVariable;
+import org.springframework.web.bind.annotation.RequestHeader;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+public class GetProjectsFromEmployee {
+    private final EmployeeService employeeService;
+
+    public GetProjectsFromEmployee(EmployeeService employeeService) {
+        this.employeeService = employeeService;
+    }
+
+    @Operation(summary = "Get all projects from employee")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "200", description = "Get all projects from employee", content = @Content),
+            @ApiResponse(responseCode = "404", description = "Employee not found", content = @Content)
+    })
+    @GetMapping("/employees/{employeeId}/projects")
+    public ResponseEntity<Object> create(
+            @PathVariable Long employeeId,
+            @RequestHeader("Authorization") String accessToken
+    ) {
+        if (!this.employeeService.employeeExists(accessToken, employeeId)) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        return new ResponseEntity<>(this.employeeService.getProjects(employeeId), HttpStatus.OK);
+    }
+}

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

@@ -0,0 +1,52 @@
+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 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.*;
+
+import java.util.Optional;
+
+@RestController
+public class RemoveEmployeeFromProjectAction {
+    private final ProjectService projectService;
+    private final EmployeeService employeeService;
+
+    public RemoveEmployeeFromProjectAction(ProjectService projectService, EmployeeService employeeService) {
+        this.projectService = projectService;
+        this.employeeService = employeeService;
+    }
+
+    @Operation(summary = "Remove an employee from a project")
+    @ApiResponses(value = {
+            @ApiResponse(responseCode = "204", description = "Employee removed from project"),
+            @ApiResponse(responseCode = "404", description = "Project or employee not found", content = @Content)
+    })
+    @DeleteMapping("/projects/{projectId}/employees/{employeeId}")
+    public ResponseEntity<Object> remove(
+            @PathVariable Long projectId,
+            @PathVariable Long employeeId,
+            @RequestHeader("Authorization") String accessToken
+    ) {
+        Optional<ProjectEntity> project = this.projectService.findById(projectId);
+
+        if (project.isEmpty()) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        if (!this.employeeService.employeeExists(accessToken, employeeId)) {
+            return new ResponseEntity<>(HttpStatus.NOT_FOUND);
+        }
+
+        project.get().getEmployees().remove(employeeId);
+        this.projectService.update(project.get());
+
+        return new ResponseEntity<>(HttpStatus.NO_CONTENT);
+    }
+}

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

@@ -0,0 +1,22 @@
+package de.szut.lf8_starter.project.dto.employee;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.List;
+
+@Getter
+@Setter
+@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/main/java/de/szut/lf8_starter/project/dto/employee/GetEmployeeDto.java

@@ -0,0 +1,11 @@
+package de.szut.lf8_starter.project.dto.employee;
+
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+public class GetEmployeeDto {
+    private long id;
+    private GetSkillDto[] skillSet;
+}

src/main/java/de/szut/lf8_starter/project/dto/employee/GetEmployeesFromProjectDto.java

@@ -0,0 +1,17 @@
+package de.szut.lf8_starter.project.dto.employee;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import lombok.Getter;
+import lombok.Setter;
+
+import java.util.ArrayList;
+
+@Getter
+@Setter
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public class GetEmployeesFromProjectDto {
+    private long projectId;
+    private String projectDescription;
+    private ArrayList<GetEmployeeDto> employees;
+}

src/main/java/de/szut/lf8_starter/project/dto/employee/GetSkillDto.java

@@ -0,0 +1,13 @@
+package de.szut.lf8_starter.project.dto.employee;
+
+import com.fasterxml.jackson.databind.PropertyNamingStrategies;
+import com.fasterxml.jackson.databind.annotation.JsonNaming;
+import lombok.Getter;
+import lombok.Setter;
+
+@Getter
+@Setter
+@JsonNaming(PropertyNamingStrategies.SnakeCaseStrategy.class)
+public class GetSkillDto {
+    private String skill;
+}

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

@@ -1,4 +1,4 @@
-package de.szut.lf8_starter.project.dto;
+package de.szut.lf8_starter.project.dto.project;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.databind.PropertyNamingStrategies;

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

@@ -1,10 +1,8 @@
-package de.szut.lf8_starter.project.dto;
+package de.szut.lf8_starter.project.dto.project;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.databind.PropertyNamingStrategies;
 import com.fasterxml.jackson.databind.annotation.JsonNaming;
-import jakarta.validation.constraints.NotBlank;
-import jakarta.validation.constraints.NotNull;
 import lombok.Getter;
 import lombok.Setter;
 

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

@@ -1,4 +1,4 @@
-package de.szut.lf8_starter.project.dto;
+package de.szut.lf8_starter.project.dto.project;
 
 import com.fasterxml.jackson.annotation.JsonFormat;
 import com.fasterxml.jackson.databind.PropertyNamingStrategies;

src/main/java/de/szut/lf8_starter/project/mapper/EmployeeFromProjectMapper.java

@@ -0,0 +1,35 @@
+package de.szut.lf8_starter.project.mapper;
+
+import de.szut.lf8_starter.employee.EmployeeService;
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.dto.employee.GetEmployeeDto;
+import de.szut.lf8_starter.project.dto.employee.GetEmployeesFromProjectDto;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+
+@Service
+public class EmployeeFromProjectMapper {
+    private final EmployeeService employeeService;
+
+    public EmployeeFromProjectMapper(EmployeeService employeeService) {
+        this.employeeService = employeeService;
+    }
+
+    public GetEmployeesFromProjectDto mapToGetEmployeesFromProjectDto(ProjectEntity projectEntity, String accessToken) {
+        GetEmployeesFromProjectDto getEmployeesFromProjectDto = new GetEmployeesFromProjectDto();
+        getEmployeesFromProjectDto.setProjectId(projectEntity.getId());
+        getEmployeesFromProjectDto.setProjectDescription(projectEntity.getComment());
+
+        ArrayList<GetEmployeeDto> employeeDtos = new ArrayList<>();
+        for (long id : projectEntity.getEmployees()) {
+            GetEmployeeDto getEmployeeDto = this.employeeService.getEmployee(accessToken, id);
+
+            employeeDtos.add(getEmployeeDto);
+        }
+
+        getEmployeesFromProjectDto.setEmployees(employeeDtos);
+
+        return getEmployeesFromProjectDto;
+    }
+}

src/main/java/de/szut/lf8_starter/project/mapper/ProjectMapper.java

@@ -1,8 +1,9 @@
-package de.szut.lf8_starter.project;
+package de.szut.lf8_starter.project.mapper;
 
-import de.szut.lf8_starter.project.dto.CreateProjectDto;
+import de.szut.lf8_starter.project.ProjectEntity;
-import de.szut.lf8_starter.project.dto.GetProjectDto;
+import de.szut.lf8_starter.project.dto.project.CreateProjectDto;
-import de.szut.lf8_starter.project.dto.UpdateProjectDto;
+import de.szut.lf8_starter.project.dto.project.GetProjectDto;
+import de.szut.lf8_starter.project.dto.project.UpdateProjectDto;
 import org.springframework.stereotype.Service;
 
 @Service

src/main/java/de/szut/lf8_starter/security/KeycloakSecurityConfig.java

@@ -1,24 +1,17 @@
 package de.szut.lf8_starter.security;
 
 import java.util.*;
-import java.util.stream.Collectors;
 
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
-import org.springframework.context.annotation.Profile;
-import org.springframework.http.HttpMethod;
 import org.springframework.security.config.Customizer;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
 import org.springframework.security.core.GrantedAuthority;
 import org.springframework.security.core.authority.SimpleGrantedAuthority;
-import org.springframework.security.core.authority.mapping.GrantedAuthoritiesMapper;
 import org.springframework.security.core.session.SessionRegistry;
 import org.springframework.security.core.session.SessionRegistryImpl;
-import org.springframework.security.oauth2.core.oidc.user.OidcUserAuthority;
-import org.springframework.security.oauth2.core.user.OAuth2UserAuthority;
 import org.springframework.security.oauth2.server.resource.authentication.JwtAuthenticationConverter;
-import org.springframework.security.oauth2.server.resource.authentication.JwtGrantedAuthoritiesConverter;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.authentication.session.RegisterSessionAuthenticationStrategy;
 import org.springframework.security.web.authentication.session.SessionAuthenticationStrategy;

src/test/java/de/szut/lf8_starter/Lf8StarterApplicationTests.java

@@ -2,7 +2,6 @@ package de.szut.lf8_starter;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;
-import org.springframework.test.context.TestPropertySource;
 
 @SpringBootTest
 class Lf8StarterApplicationTests {

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

@@ -0,0 +1,160 @@
+package de.szut.lf8_starter.integration.project;
+
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectRepository;
+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.http.*;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+class AddEmployeeToProjectTest {
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @Autowired
+    private ProjectRepository projectRepository;
+
+    @Test
+    void addEmployeeToProjectTest() throws Exception {
+        ProjectEntity project = new ProjectEntity();
+        project.setComment("comment");
+        project.setContractor(1);
+        project.setContractorName("contractorName");
+        project.setEndDate(LocalDate.of(2024, 1, 1));
+        project.setLeadingEmployee(1);
+        project.setName("name");
+        project.setStartDate(LocalDate.of(2021, 1, 1));
+        project.setEmployees(List.of(1L, 2L, 3L));
+        this.projectRepository.save(project);
+
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", 1, 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNoContent());
+
+        ProjectEntity updatedProject = projectRepository.findById(1L).get();
+
+        assert updatedProject.getEmployees().contains(312L);
+    }
+
+    @Test
+    void addEmployeeToPastProjectTest() throws Exception {
+        ProjectEntity project = new ProjectEntity();
+        project.setComment("past project");
+        project.setContractor(1);
+        project.setContractorName("contractorName");
+        project.setPlannedEndDate(LocalDate.of(1991, 1, 1));
+        project.setLeadingEmployee(1);
+        project.setName("past project");
+        project.setStartDate(LocalDate.of(1990, 1, 1));
+        project.setEmployees(List.of(1L, 2L, 3L));
+        this.projectRepository.save(project);
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", project.getId(), 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNoContent());
+
+        ProjectEntity updatedProject = projectRepository.findById(project.getId()).get();
+
+        assert updatedProject.getEmployees().contains(312L);
+    }
+
+    @Test
+    void addEmployeeToFutureProjectTest() throws Exception {
+        ProjectEntity project = new ProjectEntity();
+        project.setComment("future project");
+        project.setContractor(1);
+        project.setContractorName("contractorName");
+        project.setPlannedEndDate(LocalDate.of(2101, 1, 1));
+        project.setLeadingEmployee(1);
+        project.setName("future project");
+        project.setStartDate(LocalDate.of(2100, 1, 1));
+        project.setEmployees(List.of(1L, 2L, 3L));
+        this.projectRepository.save(project);
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", project.getId(), 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNoContent());
+
+        ProjectEntity updatedProject = projectRepository.findById(project.getId()).get();
+
+        assert updatedProject.getEmployees().contains(312L);
+    }
+
+    @Test
+    void addEmployeeToProjectWithOverlappingDatesTest() throws Exception {
+        ProjectEntity project1 = new ProjectEntity();
+        project1.setComment("project 1");
+        project1.setContractor(1);
+        project1.setContractorName("contractorName");
+        project1.setPlannedEndDate(LocalDate.of(2023, 1, 1));
+        project1.setLeadingEmployee(1);
+        project1.setName("project 1");
+        project1.setStartDate(LocalDate.of(2022, 1, 1));
+        project1.setEmployees(List.of(1L, 2L, 3L));
+        this.projectRepository.save(project1);
+
+        ProjectEntity project2 = new ProjectEntity();
+        project2.setComment("project 2");
+        project2.setContractor(1);
+        project2.setContractorName("contractorName");
+        project2.setPlannedEndDate(LocalDate.of(2023, 6, 1));
+        project2.setLeadingEmployee(1);
+        project2.setName("project 2");
+        project2.setStartDate(LocalDate.of(2022, 6, 1));
+        project2.setEmployees(List.of(1L, 2L, 3L));
+        this.projectRepository.save(project2);
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", project1.getId(), 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNoContent());
+
+        mockMvc.perform(post("/projects/{projectId}/employees/{employeeId}", project2.getId(), 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isConflict());
+    }
+
+    private String getBearerToken() {
+        String url = "https://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+
+        MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("grant_type", "password");
+        map.add("client_id", "employee-management-service");
+        map.add("username", "user");
+        map.add("password", "test");
+
+        HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
+
+        ResponseEntity<Map> response = this.restTemplate.exchange(url, HttpMethod.POST, request, Map.class);
+
+        return Objects.requireNonNull(response.getBody()).get("access_token").toString();
+    }
+}

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

@@ -1,30 +1,41 @@
 package de.szut.lf8_starter.integration.project;
 
+import de.szut.lf8_starter.project.ProjectEntity;
 import de.szut.lf8_starter.project.ProjectRepository;
 import org.json.JSONObject;
 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.http.MediaType;
+import org.springframework.http.*;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
 
 import java.time.LocalDate;
-import java.util.Arrays;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+import java.util.Optional;
 
 import static org.assertj.core.api.Assertions.assertThat;
+import static org.hamcrest.Matchers.is;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
-import static org.hamcrest.Matchers.is;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 
 @SpringBootTest
 @AutoConfigureMockMvc(addFilters = false)
-public class CreateProjectActionTest {
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+class CreateProjectActionTest {
     @Autowired
     private MockMvc mockMvc;
     @Autowired
     private ProjectRepository projectRepository;
+    @Autowired
+    private RestTemplate restTemplate;
 
     @Test
     void createProjectTest() throws Exception {
@@ -32,7 +43,7 @@ public class CreateProjectActionTest {
                 {
                     "name": "name",
                     "leading_employee": 1,
-                    "employees": [2, 3],
+                    "employees": [312],
                     "contractor": 4,
                     "contractor_name": "Peter File",
                     "comment": "goal of project",
@@ -41,13 +52,16 @@ public class CreateProjectActionTest {
                   }
                 """;
 
-        final var contentAsString = this.mockMvc.perform(
+        final String contentAsString = this.mockMvc.perform(
-                post("/projects").content(content).contentType(MediaType.APPLICATION_JSON)
+                        post("/projects")
+                                .content(content)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
                 )
                 .andExpect(status().isCreated())
                 .andExpect(jsonPath("name", is("name")))
                 .andExpect(jsonPath("leading_employee", is(1)))
-                .andExpect(jsonPath("employees", is(Arrays.asList(2, 3))))
+                .andExpect(jsonPath("employees", is(List.of(312))))
                 .andExpect(jsonPath("contractor", is(4)))
                 .andExpect(jsonPath("contractor_name", is("Peter File")))
                 .andExpect(jsonPath("comment", is("goal of project")))
@@ -57,9 +71,9 @@ public class CreateProjectActionTest {
                 .getResponse()
                 .getContentAsString();
 
-            final var id = Long.parseLong(new JSONObject(contentAsString).get("id").toString());
+        final long id = Long.parseLong(new JSONObject(contentAsString).get("id").toString());
 
-            final var project = this.projectRepository.findById(id);
+        final Optional<ProjectEntity> project = this.projectRepository.findById(id);
         assertThat(project.get().getName()).isEqualTo("name");
         assertThat(project.get().getLeadingEmployee()).isEqualTo(1);
         assertThat(project.get().getContractor()).isEqualTo(4);
@@ -68,4 +82,155 @@ public class CreateProjectActionTest {
         assertThat(project.get().getStartDate()).isEqualTo(LocalDate.of(2000, 1, 1));
         assertThat(project.get().getPlannedEndDate()).isEqualTo(LocalDate.of(2001, 1, 1));
     }
+
+    @Test
+    void createProjectShouldReturnConflictResponseOnConflictingProjects() throws Exception {
+        String content = """
+                {
+                    "name": "name",
+                    "leading_employee": 1,
+                    "employees": [312],
+                    "contractor": 4,
+                    "contractor_name": "Peter File",
+                    "comment": "goal of project",
+                    "start_date": "01.01.2000",
+                    "planned_end_date": "01.01.2001"
                   }
+                """;
+
+        this.mockMvc.perform(
+                        post("/projects")
+                                .content(content)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                )
+                .andExpect(status().isCreated());
+
+        this.mockMvc.perform(
+                        post("/projects")
+                                .content(content)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                )
+                .andExpect(status().isConflict());
+    }
+
+    @Test
+    void createProjectWithPastStartDate() throws Exception {
+        String content = """
+                {
+                    "name": "past project",
+                    "leading_employee": 1,
+                    "employees": [312],
+                    "contractor": 4,
+                    "contractor_name": "Past Contractor",
+                    "comment": "past project",
+                    "start_date": "01.01.1990",
+                    "planned_end_date": "01.01.1991"
+                  }
+                """;
+
+        this.mockMvc.perform(
+                        post("/projects")
+                                .content(content)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                )
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("name", is("past project")))
+                .andExpect(jsonPath("start_date", is("01.01.1990")))
+                .andExpect(jsonPath("planned_end_date", is("01.01.1991")));
+    }
+
+    @Test
+    void createProjectWithFutureStartDate() throws Exception {
+        String content = """
+                {
+                    "name": "future project",
+                    "leading_employee": 1,
+                    "employees": [312],
+                    "contractor": 4,
+                    "contractor_name": "Future Contractor",
+                    "comment": "future project",
+                    "start_date": "01.01.2100",
+                    "planned_end_date": "01.01.2101"
+                  }
+                """;
+
+        this.mockMvc.perform(
+                        post("/projects")
+                                .content(content)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                )
+                .andExpect(status().isCreated())
+                .andExpect(jsonPath("name", is("future project")))
+                .andExpect(jsonPath("start_date", is("01.01.2100")))
+                .andExpect(jsonPath("planned_end_date", is("01.01.2101")));
+    }
+
+    @Test
+    void createProjectWithOverlappingDates() throws Exception {
+        String content1 = """
+                {
+                    "name": "project 1",
+                    "leading_employee": 1,
+                    "employees": [312],
+                    "contractor": 4,
+                    "contractor_name": "Contractor 1",
+                    "comment": "project 1",
+                    "start_date": "01.01.2022",
+                    "planned_end_date": "01.01.2023"
+                  }
+                """;
+
+        String content2 = """
+                {
+                    "name": "project 2",
+                    "leading_employee": 1,
+                    "employees": [312],
+                    "contractor": 4,
+                    "contractor_name": "Contractor 2",
+                    "comment": "project 2",
+                    "start_date": "01.06.2022",
+                    "planned_end_date": "01.06.2023"
+                  }
+                """;
+
+        this.mockMvc.perform(
+                        post("/projects")
+                                .content(content1)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                )
+                .andExpect(status().isCreated());
+
+        this.mockMvc.perform(
+                        post("/projects")
+                                .content(content2)
+                                .contentType(MediaType.APPLICATION_JSON)
+                                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                )
+                .andExpect(status().isConflict());
+    }
+
+    private String getBearerToken() {
+        String url = "https://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+
+        MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("grant_type", "password");
+        map.add("client_id", "employee-management-service");
+        map.add("username", "user");
+        map.add("password", "test");
+
+        HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
+
+        ResponseEntity<Map> response = this.restTemplate.exchange(url, HttpMethod.POST, request, Map.class);
+
+        return Objects.requireNonNull(response.getBody()).get("access_token").toString();
+    }
+}
+

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

@@ -0,0 +1,84 @@
+package de.szut.lf8_starter.integration.project;
+
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectRepository;
+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.http.*;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+class GetEmployeesFromProjectTest {
+    @Autowired
+    private MockMvc mockMvc;
+    @Autowired
+    private ProjectRepository projectRepository;
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @Test
+    void getEmployeesFromProjectTest() throws Exception {
+        ProjectEntity project = new ProjectEntity();
+        project.setId(1);
+        project.setComment("comment");
+        project.setContractor(1);
+        project.setContractorName("contractorName");
+        project.setEndDate(LocalDate.of(2024, 1, 1));
+        project.setLeadingEmployee(1);
+        project.setName("name");
+        project.setStartDate(LocalDate.of(2021, 1, 1));
+        project.setEmployees(List.of(315L));
+        this.projectRepository.save(project);
+
+        this.mockMvc.perform(get("/projects/1/employees")
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                ).andExpect(status().isOk())
+                .andExpect(jsonPath("project_id").value(1))
+                .andExpect(jsonPath("project_description").value("comment"))
+                .andExpect(jsonPath("employees[0].id").value(315))
+                .andExpect(jsonPath("employees[0].skillSet[0].skill").value("Product Owner"));
+    }
+
+    @Test
+    void getEmployeesFromProjectShouldReturnNotFoundResponseWhenProjectIsNotFound() throws Exception {
+        this.mockMvc.perform(get("/projects/1111/employees")
+                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+        ).andExpect(status().isNotFound());
+    }
+
+    private String getBearerToken() {
+        String url = "https://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+
+        MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("grant_type", "password");
+        map.add("client_id", "employee-management-service");
+        map.add("username", "user");
+        map.add("password", "test");
+
+        HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
+
+        ResponseEntity<Map> response = this.restTemplate.exchange(url, HttpMethod.POST, request, Map.class);
+
+        return Objects.requireNonNull(response.getBody()).get("access_token").toString();
+    }
+}

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

@@ -6,6 +6,7 @@ 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.test.annotation.DirtiesContext;
 import org.springframework.test.web.servlet.MockMvc;
 
 import java.time.LocalDate;
@@ -18,6 +19,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 
 @SpringBootTest
 @AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
 class GetProjectActionTest {
     @Autowired
     private MockMvc mockMvc;
@@ -26,7 +28,7 @@ class GetProjectActionTest {
 
     @Test
     void getProjectTest() throws Exception {
-        var project = new ProjectEntity();
+        ProjectEntity project = new ProjectEntity();
         project.setId(1);
         project.setComment("comment");
         project.setContractor(1);
@@ -54,6 +56,6 @@ class GetProjectActionTest {
 
     @Test
     void getProjectShouldReturnNotFoundResponseWhenProjectIsNotFound() throws Exception {
-        this.mockMvc.perform(get("/projects/2")).andExpect(status().isNotFound());
+        this.mockMvc.perform(get("/projects/1111")).andExpect(status().isNotFound());
     }
 }

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

@@ -0,0 +1,88 @@
+package de.szut.lf8_starter.integration.project;
+
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectRepository;
+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.http.*;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+class GetProjectsFromEmployeeTest {
+    @Autowired
+    private MockMvc mockMvc;
+    @Autowired
+    private ProjectRepository projectRepository;
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @Test
+    void getProjectsFromEmployeeTest() throws Exception {
+        ProjectEntity project = new ProjectEntity();
+        project.setId(1);
+        project.setComment("comment");
+        project.setContractor(1);
+        project.setContractorName("contractorName");
+        project.setEndDate(LocalDate.of(2024, 1, 1));
+        project.setLeadingEmployee(1);
+        project.setName("name");
+        project.setStartDate(LocalDate.of(2021, 1, 1));
+        project.setEmployees(List.of(315L));
+        this.projectRepository.save(project);
+
+        this.mockMvc.perform(get("/employees/315/projects")
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                ).andExpect(status().isOk())
+                .andExpect(jsonPath("$[0].id").value(1))
+                .andExpect(jsonPath("$[0].name").value("name"))
+                .andExpect(jsonPath("$[0].leading_employee").value(1))
+                .andExpect(jsonPath("$[0].employees[0]").value(315))
+                .andExpect(jsonPath("$[0].contractor").value(1))
+                .andExpect(jsonPath("$[0].contractor_name").value("contractorName"))
+                .andExpect(jsonPath("$[0].comment").value("comment"))
+                .andExpect(jsonPath("$[0].start_date").value("01.01.2021"));
+    }
+
+    @Test
+    void GetProjectsFromEmployeeShouldReturnNotFoundResponseWhenEmployeeIsNotFound() throws Exception {
+        this.mockMvc.perform(get("/employees/1111/projects")
+                .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+        ).andExpect(status().isNotFound());
+    }
+
+    private String getBearerToken() {
+        String url = "https://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+
+        MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("grant_type", "password");
+        map.add("client_id", "employee-management-service");
+        map.add("username", "user");
+        map.add("password", "test");
+
+        HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
+
+        ResponseEntity<Map> response = this.restTemplate.exchange(url, HttpMethod.POST, request, Map.class);
+
+        return Objects.requireNonNull(response.getBody()).get("access_token").toString();
+    }
+}

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

@@ -1,37 +0,0 @@
-package de.szut.lf8_starter.integration.project;
-
-import de.szut.lf8_starter.project.ProjectEntity;
-import de.szut.lf8_starter.project.ProjectRepository;
-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.web.client.TestRestTemplate;
-import org.springframework.test.web.servlet.MockMvc;
-
-import java.time.LocalDate;
-import java.util.List;
-
-import static org.hamcrest.collection.IsCollectionWithSize.hasSize;
-import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
-import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
-
-@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
-@AutoConfigureMockMvc(addFilters = true)
-public class ProjectFindAllNotAuthenticated {
-    @Autowired
-    private ProjectRepository projectRepository;
-
-    @Autowired
-    private MockMvc mockMvc;
-
-    @Autowired
-    private TestRestTemplate restTemplate;
-
-    @Test
-    void findAllProjects() throws Exception {
-        this.mockMvc.perform(get("/projects"))
-                .andExpect(status().isUnauthorized());
-    }
-}

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

@@ -6,6 +6,7 @@ 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.test.annotation.DirtiesContext;
 import org.springframework.test.web.servlet.MockMvc;
 
 import java.time.LocalDate;
@@ -18,7 +19,8 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 
 @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
 @AutoConfigureMockMvc(addFilters = false)
-public class ProjectFindAllSuccessTest {
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+class ProjectFindAllSuccessTest {
     @Autowired
     private ProjectRepository projectRepository;
 
@@ -27,7 +29,7 @@ public class ProjectFindAllSuccessTest {
 
     @Test
     void findAllProjectsTest() throws Exception {
-        var project = new ProjectEntity();
+        ProjectEntity project = new ProjectEntity();
         project.setId(1);
         project.setComment("comment");
         project.setContractor(1);

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

@@ -0,0 +1,87 @@
+package de.szut.lf8_starter.integration.project;
+
+import de.szut.lf8_starter.project.ProjectEntity;
+import de.szut.lf8_starter.project.ProjectRepository;
+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.http.*;
+import org.springframework.test.annotation.DirtiesContext;
+import org.springframework.test.web.servlet.MockMvc;
+import org.springframework.util.LinkedMultiValueMap;
+import org.springframework.util.MultiValueMap;
+import org.springframework.web.client.RestTemplate;
+
+import java.time.LocalDate;
+import java.util.List;
+import java.util.Map;
+import java.util.Objects;
+
+import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.delete;
+import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
+
+@SpringBootTest
+@AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
+class RemoveEmployeeFromProjectIntegrationTest {
+    @Autowired
+    private MockMvc mockMvc;
+
+    @Autowired
+    private RestTemplate restTemplate;
+
+    @Autowired
+    private ProjectRepository projectRepository;
+
+    @Test
+    void removeEmployeeFromProject() throws Exception {
+        ProjectEntity project = new ProjectEntity();
+        project.setComment("comment");
+        project.setContractor(1);
+        project.setContractorName("contractorName");
+        project.setEndDate(LocalDate.of(2024, 1, 1));
+        project.setLeadingEmployee(1);
+        project.setName("name");
+        project.setStartDate(LocalDate.of(2021, 1, 1));
+        project.setEmployees(List.of(1L, 2L, 3L, 312L));
+        this.projectRepository.save(project);
+
+
+        mockMvc.perform(delete("/projects/{projectId}/employees/{employeeId}", 1, 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNoContent());
+
+        ProjectEntity updatedProject = projectRepository.findById(1L).get();
+
+        assert !updatedProject.getEmployees().contains(312L);
+    }
+
+    private String getBearerToken() {
+        String url = "https://keycloak.szut.dev/auth/realms/szut/protocol/openid-connect/token";
+
+        HttpHeaders headers = new HttpHeaders();
+        headers.setContentType(MediaType.APPLICATION_FORM_URLENCODED);
+
+        MultiValueMap<String, String> map = new LinkedMultiValueMap<>();
+        map.add("grant_type", "password");
+        map.add("client_id", "employee-management-service");
+        map.add("username", "user");
+        map.add("password", "test");
+
+        HttpEntity<MultiValueMap<String, String>> request = new HttpEntity<>(map, headers);
+
+        ResponseEntity<Map> response = this.restTemplate.exchange(url, HttpMethod.POST, request, Map.class);
+
+        return Objects.requireNonNull(response.getBody()).get("access_token").toString();
+    }
+
+    @Test
+    void removeEmployeeShouldReturn404IfProjectNotFound() throws Exception {
+        mockMvc.perform(delete("/projects/{projectId}/employees/{employeeId}", 1987234987, 312)
+                        .header(HttpHeaders.AUTHORIZATION, getBearerToken())
+                        .contentType(MediaType.APPLICATION_JSON))
+                .andExpect(status().isNotFound());
+    }
+}

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

@@ -6,6 +6,7 @@ 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.test.annotation.DirtiesContext;
 import org.springframework.test.web.servlet.MockMvc;
 
 import java.time.LocalDate;
@@ -17,6 +18,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 
 @SpringBootTest
 @AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
 class RemoveProjectActionTest {
     @Autowired
     private MockMvc mockMvc;
@@ -25,7 +27,7 @@ class RemoveProjectActionTest {
 
     @Test
     void deleteProjectTest() throws Exception {
-        var project = new ProjectEntity();
+        ProjectEntity project = new ProjectEntity();
         project.setComment("comment");
         project.setContractor(1);
         project.setContractorName("contractorName");

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

@@ -8,11 +8,13 @@ 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.http.MediaType;
+import org.springframework.test.annotation.DirtiesContext;
 import org.springframework.test.web.servlet.MockMvc;
 
 import java.time.LocalDate;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Optional;
 
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.hamcrest.Matchers.is;
@@ -22,6 +24,7 @@ import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.
 
 @SpringBootTest
 @AutoConfigureMockMvc(addFilters = false)
+@DirtiesContext(classMode = DirtiesContext.ClassMode.AFTER_EACH_TEST_METHOD)
 class UpdateProjectActionTest {
     @Autowired
     private MockMvc mockMvc;
@@ -55,7 +58,7 @@ class UpdateProjectActionTest {
                   }
                 """;
 
-        final var contentAsString = this.mockMvc.perform(
+        final String contentAsString = this.mockMvc.perform(
                         put("/projects/1").content(content).contentType(MediaType.APPLICATION_JSON)
                 )
                 .andExpect(status().isOk())
@@ -71,9 +74,9 @@ class UpdateProjectActionTest {
                 .getResponse()
                 .getContentAsString();
 
-        final var id = Long.parseLong(new JSONObject(contentAsString).get("id").toString());
+        final long id = Long.parseLong(new JSONObject(contentAsString).get("id").toString());
 
-        final var existingProject = this.projectRepository.findById(id);
+        final Optional<ProjectEntity> existingProject = this.projectRepository.findById(id);
         assertThat(existingProject.get().getName()).isEqualTo("updatedName");
         assertThat(existingProject.get().getLeadingEmployee()).isEqualTo(2);
         assertThat(existingProject.get().getContractor()).isEqualTo(6);
@@ -103,7 +106,7 @@ class UpdateProjectActionTest {
                 {}
                 """;
 
-        final var contentAsString = this.mockMvc.perform(
+        final String contentAsString = this.mockMvc.perform(
                         put("/projects/1").content(content).contentType(MediaType.APPLICATION_JSON)
                 )
                 .andExpect(status().isOk())
@@ -120,9 +123,9 @@ class UpdateProjectActionTest {
                 .getResponse()
                 .getContentAsString();
 
-        final var id = Long.parseLong(new JSONObject(contentAsString).get("id").toString());
+        final long id = Long.parseLong(new JSONObject(contentAsString).get("id").toString());
 
-        final var existingProject = this.projectRepository.findById(id);
+        final Optional<ProjectEntity> existingProject = this.projectRepository.findById(id);
         assertThat(existingProject.get().getName()).isEqualTo("name");
         assertThat(existingProject.get().getLeadingEmployee()).isEqualTo(1);
         assertThat(existingProject.get().getContractor()).isEqualTo(1);
@@ -135,6 +138,6 @@ class UpdateProjectActionTest {
 
     @Test
     void updateProjectShouldReturnNotFoundResponseWhenProjectIsNotFound() throws Exception {
-        this.mockMvc.perform(put("/projects/2").content("{}").contentType(MediaType.APPLICATION_JSON)).andExpect(status().isNotFound());
+        this.mockMvc.perform(put("/projects/98723498798").content("{}").contentType(MediaType.APPLICATION_JSON)).andExpect(status().isNotFound());
     }
 }

src/test/resources/application-test.properties

@@ -0,0 +1,6 @@
+spring.datasource.url=jdbc:h2:mem:testdb;DB_CLOSE_DELAY=-1;DB_CLOSE_ON_EXIT=FALSE
+spring.datasource.driverClassName=org.h2.Driver
+spring.datasource.username=sa
+spring.datasource.password=password
+spring.jpa.database-platform=org.hibernate.dialect.H2Dialect
+spring.jpa.hibernate.ddl-auto=create-drop