androidstudio java单元测试打印Log

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mob64ca141834d3 2024-10-28 08:33:29

文章标签 单元测试 java 开发语言 ide 文章分类 Android 移动开发

前言：

本文适用于 javaer，其他开发者或许可以借鉴。

写本文的主旨有两个，一是简单的给大家介绍下单元测试，二是通过一个简单的示例来介绍一些单元测试的技巧，希望以此来降低大家写单元测试的门槛。

1、单元测试的定义

单元测试通常是由软件开发人员编写和运营的自动化测试，以确保应用程序的一部分（称为“单元”符合其设计并按预期运行。在编程过程中，一个单元可以是一个完整的模块，但更常见的是一个单独的函数或过程。在面向对象编程中，一个单元通常是一个完整的接口，例如一个类，或者一个单独的方法。通过首先为最小的可测试单元编写测试，然后是它们之间的复合行为，可以为复杂的应用程序构建全面的测试。

Unit tests are typically automated tests written and run by software developers to ensure that a section of an application（known as the “unit”）meets its design and behaves as intended. In procedural programming，a unit could be an entire module, but it is more commonly an individual function or procedure. In object-oriented programming,a unit is often an entire interface,such as a class,or an individual method.By writing tests first for the smallest testable units,then the compound behaviors between those,one can build up comprehensive tests for complex applications.
—Wikipedia，Unit testing

简单来说，单元测试是针对一个单元编写测试方法。其中的单元可以是一个很单纯的函数，也可以是一个完整的接口，该接口中可以包含各种其他函数的调用。

2、单元测试用例

该项目的 SpringBoot 版本是 2.2.5.RELEASE。

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starters</artifactId>
    <version>2.2.5.RELEASE</version>
</parent>

➮ 2-1.项目文件准备

假设有项目文件的目录结构如下：

androidstudio java单元测试打印Log_ide

其中依赖关系为:

java-study-web-provider 依赖 java-study-web-api, java-study-common-provider
java-study-web-api 依赖 java-study-common-api
java-study-common-provider 依赖 java-study-web-api, java-study-common-api

在 java-study-web-api 包中有个rpc 包，其中有两个 rpc 接口，分别是 WebRpc.class & WebRpc2.class。然而，这两个接口的实现类在 java-study-web-provider 包中。

androidstudio java单元测试打印Log_ide_02

public interface WebRpc {

    ApiResult<String> get();

    ApiResult<String> get2(String param);
}

public interface WebRpc2 {

    ApiResult<String> get();

    ApiResult<String> get(String param);
}

@Service
public class WebRpcImpl implements WebRpc {

    @Override
    public ApiResult<String> get() {
        return ApiResult.success("get success");
    }

    @Override
    public ApiResult<String> get2(String param) {
        return ApiResult.success(param);
    }
}

@Service
public class WebRpc2Impl implements WebRpc2 {

    @Override
    public ApiResult<String> get() {
        return ApiResult.success("get success");
    }

    @Override
    public ApiResult<String> get(String param) {
        return null;
    }
}

在 java-study-common-provider 包中有个 service 包，其中有两个 service 接口以及对应的实现类，分别是CommonEntityService.class,CommonEntityService2.class,CommonEntityServiceImpl.class, CommonEntityService2Impl.class，在两个实现类中都有引用 rpc 接口。

androidstudio java单元测试打印Log_单元测试_03

public interface CommonEntityService {

    ApiResult<Void> test(CommonEntity commonEntity);
}

public interface CommonEntityService2 {
}

@Service
public class CommonEntityServiceImpl implements CommonEntityService {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CommonEntityManager commonEntityManager;
    @Autowired
    private WebRpc webRpc;


    @Override
    public ApiResult<Void> test(CommonEntity commonEntity) {
        // webRpc 单元测试时可能为null
        ApiResult<String> getRpc = webRpc.get();
        if (!getRpc.getSuccess()) {
            logger.info("getRpc fail: {}", getRpc);
            return ApiResult.error(getRpc);
        }
        ApiResult<String> getRpc2 = webRpc.get2("test");
        if (!getRpc2.getSuccess()) {
            logger.info("getRpc2 fail: {}", getRpc2);
            return ApiResult.error(getRpc2);
        }
        // 依赖远程方法调用结果
        Optional<String> remoteResultOpt = RmiUtil.getRemoteResult();
        if (!remoteResultOpt.isPresent()) {
            logger.info("getRemoteResult fail");
            return ApiResult.error(BizRespStatusEnum.SYS_ERR);
        }
        // 入库
        int insertNo = commonEntityManager.insert(commonEntity);
        logger.info("insert {} common entity", insertNo);
        return ApiResult.success(null);
    }
}

@Service
public class CommonEntityService2Impl implements CommonEntityService2 {

    @Autowired
    private WebRpc2 webRpc2;
}

➮ 2-2.针对 CommonEntityService.class 编写单元测试

先加入 SpringBootTest 依赖。

<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>

创建对应的单元测试类。

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = CommonTestApplication.class)
public class CommonEntityServiceTest {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CommonEntityService commonEntityService;

    @Test
    public void test() {
        ApiResult<Void> testSuccess = commonEntityService.test(new CommonEntity());
        Assert.isTrue(testSuccess.getSuccess(), "testSuccess fail");
        logger.info("testSuccess: {}", JSON.toJSONString(testSuccess));
    }
}

当我们去执行单元测试的 test() 方法时，会出现 NoSuchBeanDefinitionException 异常。

Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'com.peng.java.study.web.api.rpc.WebRpc2' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {@org.springframework.beans.factory.annotation.Autowired(required=true)}
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.raiseNoMatchingBeanFound(DefaultListableBeanFactory.java:1695)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:1253)
        at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:1207)
        at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:640)
        ... 43 more

这是因为我们执行单元测试的这个模块虽然依赖了 java-study-web-api 包，能够调用 rpc 方法，但是没有依赖 java-study-web-provider 包，没办法注入对应的实现类。

有三种方法可以解决这个问题：

I .将该单元测试类挪到 java-study-web-provider 包中，这样就能加载到所有的 bean 了。

这个方法有局限性，每次执行单元测试都需要加载所有模块的文件，大大的降低了单元测试的效率。

II .在注入rpc的注解 @Autowired 上加上 required = false

@Autowired(required = false)
private WebRpc2 webRpc2;

这个方法有局限性，假设每次新增的 service 类都需要注入同一个 rpc 时，那每个 rpc 的注解 @Autowired 都需要使用 required = false，不然就没办法启动单元测试，由此可见是比较麻烦的。

III.使用Mock，在执行单元测试前，将依赖但又没办法获取到实现类的 bean 注入进去。

将mokito包加入项目。

<!-- https://mvnrepository.com/artifact/org.mockito/mockito-inline -->
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-inline</artifactId>
    <version>4.5.1</version>
    <scope>test</scope>
</dependency>

<!-- https://mvnrepository.com/artifact/org.mockito/mockito-core -->
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>4.5.1</version>
    <scope>test</scope>
</dependency>

<!-- https://mvnrepository.com/artifact/net.bytebuddy/byte-buddy-agent -->
<dependency>
    <groupId>net.bytebuddy</groupId>
    <artifactId>byte-buddy-agent</artifactId>
    <version>1.12.9</version>
    <scope>test</scope>
</dependency>

<!-- https://mvnrepository.com/artifact/net.bytebuddy/byte-buddy -->
<dependency>
    <groupId>net.bytebuddy</groupId>
    <artifactId>byte-buddy</artifactId>
    <version>1.12.8</version>
</dependency>

使用 @MockBean 和 MockitoAnnotations.openMocks(this) 可以将依赖的 bean 注入进去。

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = CommonTestApplication.class)
public class CommonEntityServiceTest {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CommonEntityService commonEntityService;
    @MockBean
    public WebRpc webRpc;
    @MockBean
    public WebRpc2 webRpc2;

    @BeforeEach
    public void before(){
        MockitoAnnotations.openMocks(this);
    }

    @Test
    public void test() {
        ApiResult<Void> testSuccess = commonEntityService.test(new CommonEntity());
        Assert.isTrue(testSuccess.getSuccess(), "testSuccess fail");
        logger.info("testSuccess: {}", JSON.toJSONString(testSuccess));
    }
}

此时再执行 test() 方法，不再出现 NoSuchBeanDefinitionException 异常，但会出现 NullPointerException 异常。这是因为我们虽然注入了 bean，但这个 bean 是个空的，因此在 commonEntityService.test 方法中执行 webRpc.get() 时，会报 NullPointerException 异常。为解决这个问题，我们可以继续使用 mock，Mockito.when(). thenReturn()。

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = CommonTestApplication.class)
public class CommonEntityServiceTest {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CommonEntityService commonEntityService;
    @MockBean
    public WebRpc webRpc;
    @MockBean
    public WebRpc2 webRpc2;

    @BeforeEach
    public void before(){
        MockitoAnnotations.openMocks(this);
    }

    @Test
    public void test() {
        Mockito.when(webRpc.get()).thenReturn(ApiResult.success("mock result 1"));
        Mockito.when(webRpc.get2("test")).thenReturn(ApiResult.success("mock result 2"));
        ApiResult<Void> testSuccess = commonEntityService.test(new CommonEntity());
        Assert.isTrue(testSuccess.getSuccess(), "testSuccess fail");
        logger.info("testSuccess: {}", JSON.toJSONString(testSuccess));
    }
}

再次执行 test() 方法，此时执行已经成功了，打印日志如下所示。

2022-05-21 22:23:23.094  INFO 3760 --- [           main] c.p.j.s.c.c.s.i.CommonEntityServiceImpl  : insert 0 common entity
2022-05-21 22:23:23.161  INFO 3760 --- [           main] c.p.j.s.c.c.s.CommonEntityServiceTest    : apiResult: {"code":"200","msg":"调用成功","success":true}

虽然已经成功执行了单元测试，但如果需要 mock 的 bean 很多的话，那不是每个测试类都需要写一遍 mock，很浪费时间啊，因此，我们可以把需要 mock 的 bean 全都放到一个类中进行管理。

@Component
public class CommonMockFactory {

    @BeforeEach
    public void before(){
        MockitoAnnotations.openMocks(this);
    }

    @MockBean
    public WebRpc webRpc;
    @MockBean
    public WebRpc2 webRpc2;
}

然后在需要单元测试的类中进行注入即可。

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = CommonTestApplication.class)
public class CommonEntityServiceTest {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CommonEntityService commonEntityService;
    @Autowired
    private CommonMockFactory commonMockFactory;

    @Test
    public void test() {
        Mockito.when(commonMockFactory.webRpc.get()).thenReturn(ApiResult.success("mock result 1"));
        Mockito.when(commonMockFactory.webRpc.get2("test")).thenReturn(ApiResult.success("mock result 2"));
        ApiResult<Void> testSuccess = commonEntityService.test(new CommonEntity());
        Assert.isTrue(testSuccess.getSuccess(), "testSuccess fail");
        logger.info("testSuccess: {}", JSON.toJSONString(testSuccess));
    }
}

➮ 2-3.提高单元测试覆盖率

使用idea自带的单元测试覆盖率工具可以查看相应的覆盖率。绿色的条代表已覆盖，红色的条代表未覆盖。

androidstudio java单元测试打印Log_单元测试_04

以下是单元测试的覆盖率文档，分别是类覆盖率、方法覆盖率、行覆盖率，从图中可以看出我们的行覆盖率只有64%，还有提升的空间。

androidstudio java单元测试打印Log_单元测试_05

如何提升呢？答案就是 mock。

先上改造后的代码：

@ExtendWith(SpringExtension.class)
@SpringBootTest(classes = CommonTestApplication.class)
public class CommonEntityServiceTest {

    private final Logger logger = LoggerFactory.getLogger(this.getClass());

    @Autowired
    private CommonEntityService commonEntityService;
    @Autowired
    private CommonMockFactory commonMockFactory;

    @Test
    public void test() {
        Mockito.when(commonMockFactory.webRpc.get()).thenReturn(ApiResult.success("mock result 1"));
        Mockito.when(commonMockFactory.webRpc.get2("test")).thenReturn(ApiResult.success("mock result 2"));
        ApiResult<Void> testSuccess = commonEntityService.test(new CommonEntity());
        Assert.isTrue(testSuccess.getSuccess(), "testSuccess fail");
        logger.info("testSuccess: {}", JSON.toJSONString(testSuccess));
    }

    @Test
    public void testWithMock() {
        Mockito.when(commonMockFactory.webRpc.get()).thenReturn(ApiResult.success("mock result 1"));
        Mockito.when(commonMockFactory.webRpc.get2("test")).thenReturn(ApiResult.success("mock result 2"));
        ApiResult<Void> testSuccess = commonEntityService.test(new CommonEntity());
        Assert.isTrue(testSuccess.getSuccess(), "testSuccess fail");
        logger.info("testSuccess: {}", JSON.toJSONString(testSuccess));

        // 模拟 webRpc.get() 失败
        Mockito.when(commonMockFactory.webRpc.get()).thenReturn(ApiResult.error(BizRespStatusEnum.ILLEGAL_PARAM));
        Mockito.when(commonMockFactory.webRpc.get2("test")).thenReturn(ApiResult.success("mock result 2"));
        ApiResult<Void> testFail1 = commonEntityService.test(new CommonEntity());
        Assert.isTrue(!testFail1.getSuccess(), "testFail1 fail");
        logger.info("testFail1: {}", JSON.toJSONString(testFail1));

        Mockito.when(commonMockFactory.webRpc.get()).thenReturn(ApiResult.success("mock result 1"));
        // 模拟 webRpc.get2() 失败
        Mockito.when(commonMockFactory.webRpc.get2("test")).thenReturn(ApiResult.error(BizRespStatusEnum.ILLEGAL_PARAM));
        ApiResult<Void> testFail2 = commonEntityService.test(new CommonEntity());
        Assert.isTrue(!testFail2.getSuccess(), "testFail1 fail");
        logger.info("testFail2: {}", JSON.toJSONString(testFail2));

        Mockito.when(commonMockFactory.webRpc.get()).thenReturn(ApiResult.success("mock result 1"));
        Mockito.when(commonMockFactory.webRpc.get2("test")).thenReturn(ApiResult.success("mock result 2"));
        try (MockedStatic<RmiUtil> rmiUtilMockedStatic = Mockito.mockStatic(RmiUtil.class)) {
            // 模拟 RmiUtil.getRemoteResult() 失败
            rmiUtilMockedStatic.when(RmiUtil::getRemoteResult).thenReturn(Optional.empty());
            ApiResult<Void> testFail3 = commonEntityService.test(new CommonEntity());
            Assert.isTrue(!testFail3.getSuccess(), "testFail3 fail");
            logger.info("testFail3: {}", JSON.toJSONString(testFail3));
        }
    }
}

单元测试的执行结果。

2022-05-21 23:23:46.516  INFO 35136 --- [           main] c.p.j.s.c.c.s.i.CommonEntityServiceImpl  : insert 0 common entity
2022-05-21 23:23:46.589  INFO 35136 --- [           main] c.p.j.s.c.c.s.CommonEntityServiceTest    : testSuccess: {"code":"200","msg":"调用成功","success":true}
2022-05-21 23:23:46.590  INFO 35136 --- [           main] c.p.j.s.c.c.s.i.CommonEntityServiceImpl  : getRpc fail: ApiResult{success=false, code='400', msg='参数异常', result=null}
2022-05-21 23:23:46.590  INFO 35136 --- [           main] c.p.j.s.c.c.s.CommonEntityServiceTest    : testFail1: {"code":"400","msg":"参数异常","success":false}
2022-05-21 23:23:46.591  INFO 35136 --- [           main] c.p.j.s.c.c.s.i.CommonEntityServiceImpl  : getRpc2 fail: ApiResult{success=false, code='400', msg='参数异常', result=null}
2022-05-21 23:23:46.591  INFO 35136 --- [           main] c.p.j.s.c.c.s.CommonEntityServiceTest    : testFail2: {"code":"400","msg":"参数异常","success":false}
2022-05-21 23:23:46.629  INFO 35136 --- [           main] c.p.j.s.c.c.s.i.CommonEntityServiceImpl  : getRemoteResult fail
2022-05-21 23:23:46.629  INFO 35136 --- [           main] c.p.j.s.c.c.s.CommonEntityServiceTest    : testFail3: {"code":"002","msg":"系统异常","success":false}

再来看看改造之后的覆盖率！从下图中可以看出单元测试的行覆盖率达到了100%，惊不惊喜，意不意外！

androidstudio java单元测试打印Log_开发语言_06