弹簧启动RESTFUL控制器的单元测试

时间：2019-11-26 13:09:42

标签： java spring-boot unit-testing mockito mockmvc

我正在尝试对Spring Boot RESTFUL控制器进行单元测试，但是我收到了空指针异常。该应用程序有一个StudentController，它取决于StudentService。 这是控制器代码：

package com.demo.student.demo.controller;

import com.demo.student.demo.annotation.ApiDescription;
import com.demo.student.demo.entity.Student;
import com.demo.student.demo.entity.StudentDto;
import com.demo.student.demo.service.StudentService;
import io.swagger.annotations.Api;
import io.swagger.annotations.ApiOperation;
import org.modelmapper.ModelMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;
import java.util.List;
import java.util.stream.Collectors;

@RestController
@RequestMapping(value = "/v1/students")
@Api(description = "This is a general description for StudentController RESTFUL Controller")
public class StudentController {

    private StudentService studentService;
    private ModelMapper modelMapper;

    public StudentController(ModelMapper modelMapper, StudentService studentService){
        this.studentService = studentService;
        this.modelMapper = modelMapper;
    }

    private StudentDto convertToDto(Student student) {
        StudentDto studentDto = modelMapper.map(student, StudentDto.class);
        return studentDto;
    }

    private Student convertToEntity(StudentDto studentDto) {
        Student student = modelMapper.map(studentDto, Student.class);
        return student;
    }

    @GetMapping
    @ApiOperation("Returns a list of all students in the system.")
    @ApiDescription("FIND_ALL_STUDENTS.md")
    public List<StudentDto> findAll(){
        List<Student> students = studentService.findAl();
        return students.stream()
                .map(student -> convertToDto(student))
                .collect(Collectors.toList());
    }

    @GetMapping("/{id}")
    @ApiOperation("Returns a specific Student by his/her identifier. 404 if does not exist.")
    @ApiDescription("FIND_STUDENT_BY_ID.md")
    public StudentDto findById(@PathVariable("id") long id){
        return convertToDto(studentService.findById(id));
    }

    @PostMapping
    @ApiOperation("Creates/Updates a new Student.")
    @ApiDescription("SAVE_OR_UPDATE_STUDENT.md")
    public StudentDto saveOrUpdate(@RequestBody StudentDto studentDto) {
        Student student = convertToEntity(studentDto);
        student.setUsername(student.getEmail() + "----" + student.getId());
        Student studentCreated = studentService.saveOrUpdate(student);
        return convertToDto(studentCreated);
    }

    @DeleteMapping("/{id}")
    @ApiOperation("Deletes a Student from the system. 404 if the Student's identifier is not found.")
    @ApiDescription("DELETE_STUDENT_BY_ID.md")
    public void deleteById(@PathVariable("id") long id){
        studentService.deleteById(id);
    }

}

这是服务实现代码：

package com.demo.student.demo.service;

import com.demo.student.demo.entity.Student;
import com.demo.student.demo.exception.StudentNotFoundException;
import com.demo.student.demo.repository.StudentRepository;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;


@Service
public class StudentServiceImpl implements StudentService {

    private StudentRepository studentRepository;

    @Autowired
    public StudentServiceImpl(StudentRepository studentRepository){
        this.studentRepository = studentRepository;
    }

    @Override
    public List<Student> findAl() {
        return studentRepository.findAll();
    }

    @Override
    public Student findById(long id) {
        return  studentRepository.findById(id).orElseThrow(() -> new StudentNotFoundException(id));
    }

    @Override
    public Student saveOrUpdate(Student student) {
        studentRepository.save(student);
        return student;
    }

    @Override
    public void deleteById(long id) {
        if(this.findById(id) != null)
            studentRepository.deleteById(id);
    }

}

这是控制器的测试类：

package com.demo.student.demo.controller;

import com.demo.student.demo.entity.Student;
import com.demo.student.demo.service.StudentService;
import com.demo.student.demo.service.StudentServiceImpl;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.Test;
import org.junit.runner.RunWith;
import org.mockito.InjectMocks;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.web.servlet.MockMvc;

import java.util.Arrays;
import java.util.List;

import static org.mockito.BDDMockito.given;
import static org.mockito.Mockito.mock;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@WebMvcTest(StudentController.class)
class StudentControllerTest {

    private final static String URI = "/v1/students";

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private StudentService studentService;

    @Test
    void findAll() throws Exception {    
        // given
        Student student = new Student(1, "test", "test@test.test");
        List<Student> students = Arrays.asList(student);
        given(studentService.findAl()).willReturn(students);

        // when + then
        mockMvc.perform(get(URI))
                .andExpect(status().isOk())
                .andExpect(content().json("[{'id':1,'email':'test@test.test'}]"));
    }

}

这也是pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.demo.student</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.modelmapper/modelmapper -->
        <dependency>
            <groupId>org.modelmapper</groupId>
            <artifactId>modelmapper</artifactId>
            <version>0.7.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.plugin</groupId>
            <artifactId>spring-plugin-core</artifactId>
            <version>1.2.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-bean-validators</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>javax.xml</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-engine -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.2.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.25.0-GA</version>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>2.22.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.skyscreamer</groupId>
            <artifactId>jsonassert</artifactId>
            <version>1.5.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

运行测试时，我收到指向StudentController类中代码行的NULL POINTER EXCEPTION，学生服务将在其中检索所有学生数据：List<Student> students = studentService.findAl(); 

java.lang.NullPointerException: null
    at com.demo.student.demo.controller.StudentController.findAll

谁能告诉我这是什么问题？

3 个答案:

答案 0 :(得分：0)

以这种方式注释测试类。 

@RunWith(SpringRunner.class)
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)

自动为此：

@Autowired
private WebApplicationContext wac;

这只是一个类变量：

private MockMvc mockMvc;

您的设置方法：

@Before
    public void setup() {

        this.mockMvc = MockMvcBuilders.webAppContextSetup(this.wac).build();

    }

在此行之前：

given（studentService.findAl（））。willReturn（students）; 创建：

 StudentService studentService = org.mockito.Mockito.mock(StudentService.class);

它应该运行。

答案 1 :(得分：0)

您的测试有两点，首先，您要混合JUnit4和JUnit5，第二，您要尝试对付Spring Boot创建的模拟，不要。最后，您将为服务和注册行为创建一个新的模拟。

  1. 删除@RunWith批注，该批注用于JUnit4测试，JUnit5不需要。
  2. 删除您的@BeforeEach方法，因为它会干扰Spring Boot（通过MockMvc通过@WebMvcTest创建的模拟@MockBean的准备工作。
  3. 从测试方法中删除StudentService studentService = mock(StudentService.class);。 @MockBean已经创建了一个模拟。这将创建一个新的模拟，而不绑定到控制器。
  4. 使用的Spring Boot版本（2.0.x）尚没有包含@WebMvcTest批注的@ExtendWith（从Spring Boot 2.1.x开始）。因此，还要添加它以使用适当的执行模型。

专业提示：从您的@Autowired中删除no-args构造函数和StudentController，Spring足够聪明，可以选择单个构造函数。

答案 2 :(得分：0)

最后，我找到了答案，添加了@ExtendWith(SpringExtension.class)以便在JUnit5中工作。
因此，我的控制器测试类为：

package com.demo.student.demo.controller;

import com.demo.student.demo.entity.Student;
import com.demo.student.demo.service.StudentService;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import org.springframework.test.web.servlet.MockMvc;

import java.util.Arrays;
import java.util.List;

import static org.mockito.BDDMockito.given;
import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.*;

@ExtendWith(SpringExtension.class)
@WebMvcTest
class StudentControllerTest {

    private final static String URI = "/v1/students";

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private StudentService studentService;

    @Test
    void findAll() throws Exception {
        // given
        Student student = new Student(1, "test", "test@test.test");
        List<Student> students = Arrays.asList(student);
        given(studentService.findAl()).willReturn(students);

        // when + then
        mockMvc.perform(get(URI))
                .andExpect(status().isOk())
                .andExpect(content().json("[{'id':1,'email':'test@test.test'}]"));
    }

}

这也是pom.xml：

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://maven.apache.org/POM/4.0.0"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.0.5.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>com.demo.student</groupId>
    <artifactId>demo</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>demo</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-jpa</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>com.h2database</groupId>
            <artifactId>h2</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.postgresql</groupId>
            <artifactId>postgresql</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
            <optional>true</optional>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>junit</groupId>
                    <artifactId>junit</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.modelmapper/modelmapper -->
        <dependency>
            <groupId>org.modelmapper</groupId>
            <artifactId>modelmapper</artifactId>
            <version>0.7.5</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.plugin</groupId>
            <artifactId>spring-plugin-core</artifactId>
            <version>1.2.0.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger2</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-swagger-ui</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>io.springfox</groupId>
            <artifactId>springfox-bean-validators</artifactId>
            <version>2.8.0</version>
        </dependency>
        <dependency>
            <groupId>javax.xml</groupId>
            <artifactId>jaxb-api</artifactId>
            <version>2.1</version>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.junit.jupiter/junit-jupiter-engine -->
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-engine</artifactId>
            <version>5.2.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.javassist</groupId>
            <artifactId>javassist</artifactId>
            <version>3.25.0-GA</version>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>2.22.0</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.skyscreamer</groupId>
            <artifactId>jsonassert</artifactId>
            <version>1.5.0</version>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>
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