java之 junit单元测试案例【经典版】

一  junit单元测试

1.1 单元测试作用

单元测试要满足AIR原则，即

A： automatic 自动化；

I: Independent  独立性；

R：Repeatable 可重复；

2.单元测试必须使用assert来验证

1.2 案例1 常规单元测试

1.代码

public class CalcDemo
{public int add(int x ,int y){return x + y;//return x * y;}public int sub(int x ,int y){return x - y;}
}

2.测试

public class AppTest {@Testvoid sub(){CalcDemo calcDemo = new CalcDemo();int retValue = calcDemo.sub(2, 2);assertEquals(0,retValue);System.out.println("");}
}

1.3 案例2 单元覆盖率Coverage*

1.代码

public class ScoreDemo
{public String scoreLevel(int score){if(score <= 0) {throw new IllegalArgumentException("缺考");} else if (score < 60) {return "弱";} else if (score < 70) {return "差";} else if (score <= 80) {return "中";} else if (score < 90) {return "良";} else {return "优";}}
}

2.测试

class ScoreDemoTest
{@Testvoid scoreLevel(){ScoreDemo scoreDemo = new ScoreDemo();assertEquals("弱",scoreDemo.scoreLevel(52));}@Testvoid scoreLevelv2(){ScoreDemo scoreDemo = new ScoreDemo();assertEquals("差",scoreDemo.scoreLevel(62));}@Testvoid scoreLevelv3(){ScoreDemo scoreDemo = new ScoreDemo();assertEquals("中",scoreDemo.scoreLevel(80));}@Testvoid scoreLevelv4(){ScoreDemo scoreDemo = new ScoreDemo();assertThrows(IllegalArgumentException.class,() -> scoreDemo.scoreLevel(-7));}
}

查看测试报告：对应覆盖率

1.4 案例3 BeforeEach，BeforeAfterall

1.代码

public class CalcDemo
{public int add(int x ,int y){return x + y;//return x * y;}public int sub(int x ,int y){return x - y;}
}

2.测试 

class CalcDemoTestV2
{CalcDemo calcDemo = null;static StringBuffer stringBuffer = null;@BeforeAllstatic void m1(){stringBuffer = new StringBuffer("abc");System.out.println("===============: "+stringBuffer.length());}@AfterAllstatic void m2(){System.out.println("===============: "+stringBuffer.append(" ,end").toString());}@BeforeEachvoid setUp(){System.out.println("----come in BeforeEach");calcDemo = new CalcDemo();}@AfterEachvoid tearDown(){System.out.println("----come in AfterEach");calcDemo = null;}@Testvoid add(){assertEquals(5,calcDemo.add(1,4));assertEquals(5,calcDemo.add(2,3));}@Testvoid sub(){assertEquals(5,calcDemo.sub(10,5));}
}

3.结果

1.5 案例4  junit+反射+注解实现测试

1.定义注解

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
public @interface AtguiguTest
{
}

2.定义调用类

public class CalcHelpDemo
{public int mul(int x ,int y){return x * y;}@AtguiguTestpublic int div(int x ,int y){return x / y;}@AtguiguTestpublic void thank(int x ,int y){System.out.println("3ks，help me test bug");}
}

3.定义测试类

@Slf4j
public class AutoTestClient
{public static void main(String[] args) throws IOException, ClassNotFoundException, NoSuchMethodException, InvocationTargetException, InstantiationException, IllegalAccessException{//家庭作业，抽取一个方法，（class，p....）CalcHelpDemo calcHelpDemo = new CalcHelpDemo();int para1 = 10;int para2 = 0;Method[] methods = calcHelpDemo.getClass().getMethods();AtomicInteger bugCount = new AtomicInteger();// 要写入的文件路径（如果文件不存在，会创建该文件）String filePath = "BugReport"+ (DateUtil.format(new Date(), "yyyyMMddHHmmss"))+".txt";for (int i = 0; i < methods.length; i++){if (methods[i].isAnnotationPresent(AtguiguTest.class)){try{methods[i].invoke(calcHelpDemo,para1,para2);//放行} catch (Exception e) {bugCount.getAndIncrement();log.info("异常名称:{},异常原因:{}",e.getCause().getClass().getSimpleName(),e.getCause().getMessage());FileUtil.writeString(methods[i].getName()+"\t"+"出现了异常"+"\n", filePath, "UTF-8");FileUtil.appendString("异常名称:"+e.getCause().getClass().getSimpleName()+"\n", filePath, "UTF-8");FileUtil.appendString("异常原因:"+e.getCause().getMessage()+"\n", filePath, "UTF-8");}finally {FileUtil.appendString("异常数:"+bugCount.get()+"\n", filePath, "UTF-8");}}}}
}

4.查看结果

1.6 案例5  web工程单元测试

1.pom配置

   <!--test--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-web</artifactId></dependency><!--test--><dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope></dependency>

2.处理类

@Service
public class MemberService
{public String add(Integer uid){System.out.println("---come in addUser,your uid is: "+uid);if (uid == -1){throw new IllegalArgumentException("parameter is negative。。。。");}return "ok";}public int del(Integer uid){System.out.println("---come in del,your uid is: "+uid);return uid;}
}

3.启动类

@SpringBootApplication
public class App 
{public static void main( String[] args ){SpringApplication.run(App.class, args);System.out.println( "Hello World!" );}
}

4.测试类

@SpringBootTest
public class MemberTest {@Resource //真实调用，落盘mysql-MQ=redis。。。。测试条件充分的情况下private MemberService memberService1;//    @Test
//    void m1()
//    {
//        String result = memberService1.add(2);
//        assertEquals("ok",result);
//
//        System.out.println("----m1 over");
//    }@MockBeanprivate MemberService memberService2;//    @Test
//    void m2_NotMockRule()
//    {
//        String result = memberService2.add(2);
//        assertEquals("ok",result);
//
//        System.out.println("----m2_NotMockRule over");
//    }//    @Test
//    void m2_WithMockRule()
//    {
//        when(memberService2.add(3)).thenReturn("ok");//不真的进入数据库/MQ，不落盘，改变return
//
//        String result = memberService2.add(3);
//        assertEquals("ok",result);
//
//        System.out.println("----m2_WithMockRule over");
//    }
@SpyBean //有规则按照规则走，没有规则走真实
private MemberService memberService3;@Testvoid m3(){when(memberService3.add(2)).thenReturn("ok");String result = memberService3.add(2);System.out.println("----add result:  "+result);Assertions.assertEquals("ok",result);int result2 = memberService3.del(3);System.out.println("----del result2:  "+result2);Assertions.assertEquals(3,result2);//跨部门调用，不是写代码，累的是心，协调工作。    zzyybs@126.comSystem.out.println("----over");}
}

4.结果