Spring boot 弹簧&x2B；Powermock+；JUnit从一个服务调用另一个服务-NullPointerException

获取NullPointerException。不知道我做错了什么。任何帮助都将不胜感激

在调用时获取空指针

Teacher t = teacherService.getTeacherDetails();

我进行了调试，发现teacherService为空。我不知道为什么它是空的，因为我已经在我的测试类中模拟了这个对象

StudentServiceTest.java

@RunWith(PowerMockRunner.class)
@PrepareForTest({StudentService.class, TeacherService.class})
public class StudentServiceTest{

    @InjectMocks
    StudentService studentService;

    @InjectMocks
    TeacherService teacherService;

    @Mock
    private StudentRepository studentRepository;

    @Mock
    private TeacherRepository teacherRepository;

    @Test
    public void getStudentInformation() {
        Student student = new Student();
        Teacher teacher = new Teacher();

        when(studentRepository.getStudentDetails()).thenReturn(student);
        when(teacherRepository.getTeacherDetails()).thenReturn(teacher);

        Student student = studentService.getStudentInformaition();

    }

   private TeacherService teacherService;

   @Autowired
    public StudentService(TeacherService teacherService) {
        this.teacherService = teacherService;
    }

    public Student getStudentInformaition() {
        Teacher t = teacherService.getTeacherDetails();
        // some logic
        Student s = studentRepository.getStudentDetails();
       // some more logic
       return s;
    }

 public Teacher getTeacherDetails() {
        Teacher t = teacherRepository.getTeacherDetails();
        return t;
    }

StudentService.java

@RunWith(PowerMockRunner.class)
@PrepareForTest({StudentService.class, TeacherService.class})
public class StudentServiceTest{

    @InjectMocks
    StudentService studentService;

    @InjectMocks
    TeacherService teacherService;

    @Mock
    private StudentRepository studentRepository;

    @Mock
    private TeacherRepository teacherRepository;

    @Test
    public void getStudentInformation() {
        Student student = new Student();
        Teacher teacher = new Teacher();

        when(studentRepository.getStudentDetails()).thenReturn(student);
        when(teacherRepository.getTeacherDetails()).thenReturn(teacher);

        Student student = studentService.getStudentInformaition();

    }

   private TeacherService teacherService;

   @Autowired
    public StudentService(TeacherService teacherService) {
        this.teacherService = teacherService;
    }

    public Student getStudentInformaition() {
        Teacher t = teacherService.getTeacherDetails();
        // some logic
        Student s = studentRepository.getStudentDetails();
       // some more logic
       return s;
    }

 public Teacher getTeacherDetails() {
        Teacher t = teacherRepository.getTeacherDetails();
        return t;
    }

TeacherService.java

@RunWith(PowerMockRunner.class)
@PrepareForTest({StudentService.class, TeacherService.class})
public class StudentServiceTest{

    @InjectMocks
    StudentService studentService;

    @InjectMocks
    TeacherService teacherService;

    @Mock
    private StudentRepository studentRepository;

    @Mock
    private TeacherRepository teacherRepository;

    @Test
    public void getStudentInformation() {
        Student student = new Student();
        Teacher teacher = new Teacher();

        when(studentRepository.getStudentDetails()).thenReturn(student);
        when(teacherRepository.getTeacherDetails()).thenReturn(teacher);

        Student student = studentService.getStudentInformaition();

    }

   private TeacherService teacherService;

   @Autowired
    public StudentService(TeacherService teacherService) {
        this.teacherService = teacherService;
    }

    public Student getStudentInformaition() {
        Teacher t = teacherService.getTeacherDetails();
        // some logic
        Student s = studentRepository.getStudentDetails();
       // some more logic
       return s;
    }

 public Teacher getTeacherDetails() {
        Teacher t = teacherRepository.getTeacherDetails();
        return t;
    }

---

问题是这个代码

@InjectMocks
StudentService studentService;

将定义的模拟对象实例注入

studentService

实例，但

TeacherService

的实例不是模拟，因此不会作为模拟注入

studentService

实例

您应该将代码调整为以下内容：

@RunWith(PowerMockRunner.class)
@PrepareForTest({StudentService.class, TeacherService.class})
public class StudentServiceTest{

    @InjectMocks
    StudentService studentService;

    @Mock
    TeacherService teacherService;

    @Mock
    private StudentRepository studentRepository;

    @Test
    public void getStudentInformation() {
        Student student = new Student();
        Teacher teacher = mock(Teacher.class);

        when(studentRepository.getStudentDetails()).thenReturn(student);
        when(teacherService.getTeacherDetails()).thenReturn(teacher);
        when(teacher.getFoo()).thenReturn(???);

        Student student = studentService.getStudentInformaition();

    }

---

请注意，

teacherService

现在是一个模拟对象实例，不再需要

TeacherRepository

，因为您正在进行单元测试

StudentService

，那么您应该只将模拟注入到

StudentService

的实例中，包括

teacherService

的模拟实例，这有什么作用

getstudentinformation（）

return

Student s

？@StalateofTuning是，updatedmy的目标是调用Student服务，该服务将调用教师服务并执行业务逻辑。如果我只是模拟教师服务，我的目标将无法实现。那么您就不是单元测试

StudentService

。如果您真的非常想走这条路，那么您需要避免

@InjectMocks

的魔力，并手动构建

StudentService

@SK的实例。您不应该在

teacherService

类中测试

teacherService

。顺便说一句，

@Autowired

是一个Spring的东西，在这里不起作用。PowerMockito将忽略该注释