Mock依赖：
SpringBoot依赖

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <artifactId>spring-test</artifactId>
                    <groupId>org.springframework</groupId>
                </exclusion>
            </exclusions>
        </dependency>
        <!-- https://mvnrepository.com/artifact/org.springframework/spring-test -->
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>5.0.1.RELEASE</version>
            <scope>test</scope>
        </dependency>

SpringMvc依赖:

<dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-all</artifactId>
            <version>1.8.5</version>
            <scope>test</scope>
        </dependency>
  <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
            <version>${spring.version}</version>
            <scope>test</scope>
        </dependency>

 <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.12</version>
        </dependency>

Mock对象

DemoDao demoDao = mock(DemoDao.class);

对象注入到bean

ReflectionTestUtils.setField(demoBean, "demoDao", demoDao);

mock的对象只对demoBean有效，其他地方用到了demoDao，需要重新注入（ReflectionTestUtils.setField(demoBean2, "demoDao", demoDao);）

MockBean

@Service
public class DemoServiceMock {
    @MockBean
    protected DemoService demoService;
    /**
     * mock调用方法
     */
    public void mockPInstanceNull(String param) {
        when(demoService.demoTest(ArgumentMatchers.eq(param))).thenReturn("demoTestString");
    } }

注意:
1.DemoServiceMock 不能被继承，否则会报错

1. @MockBean
   protected DemoService demoService;

不能在其他地方声明，否则报错
3.尽量使用eq()方法，慎用any**()方法