当程序出现异常或者测试中有异常测试案例可以使他抛出异常

例如：0不可以当做除数，如果将除数设置为0会抛出异常

在testNG上加上 expectedExceptions = ArithmeticException.class

运行测试案例测试通过

package com.lc.testngYiChang;

import org.testng.annotations.Test;

public class testNG04 {
@Test(expectedExceptions = ArithmeticException.class)
public void testNG04_01() {
int a = 0 ;
int b = 1 ;
System.out.println("我是testNG04类的testNG04——01方法,我在异常之前打印。");

  System.out.println("我是b/a  "+b/a);

  System.out.println("我是testNG04类的testNG04——01方法,我在异常之后打印。");  

}
}

如果程序正常，在测方法上加上 expectedExceptions = ArithmeticException.class ，会报出程序异常

package com.lc.testngYiChang;

import org.testng.annotations.Test;

public class testNG04 {
@Test(expectedExceptions = ArithmeticException.class)
public void testNG04_01() {
int a = 0 ;
int b = 1 ;
System.out.println("我是testNG04类的testNG04——01方法,我在异常之前打印。");

  System.out.println("我是b/a  "+b/b);

  System.out.println("我是testNG04类的testNG04——01方法,我在异常之后打印。");  

}

}

[TestNG] Running:
C:\Users\lc\AppData\Local\Temp\testng-eclipse-466935271\testng-customsuite.xml

我是testNG04类的testNG04——01方法,我在异常之前打印。
我是b/a 1
我是testNG04类的testNG04——01方法,我在异常之后打印。
FAILED: testNG04_01
org.testng.TestException:
Method testNG04.testNG04_01()[pri:0, instance:com.lc.testngYiChang.testNG04@256216b3] should have thrown an exception of type class java.lang.ArithmeticException
at org.testng.internal.ExpectedExceptionsHolder.noException(ExpectedExceptionsHolder.java:89)
at org.testng.internal.Invoker.handleInvocationResults(Invoker.java:1376)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:677)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:816)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1124)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:108)
at org.testng.TestRunner.privateRun(TestRunner.java:774)
at org.testng.TestRunner.run(TestRunner.java:624)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:359)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:354)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:312)
at org.testng.SuiteRunner.run(SuiteRunner.java:261)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1191)
at org.testng.TestNG.runSuitesLocally(TestNG.java:1116)
at org.testng.TestNG.run(TestNG.java:1024)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:112)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:205)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:176)

===============================================
Default test

Tests run: 1, Failures: 1, Skips: 0

===============================================
Default suite

Total tests run: 1, Failures: 1, Skips: 0

[TestNG] Time taken by org.testng.reporters.EmailableReporter2@61064425: 11 ms
[TestNG] Time taken by org.testng.reporters.jq.Main@16f65612: 59 ms
[TestNG] Time taken by org.testng.reporters.JUnitReportReporter@6bc168e5: 5 ms
[TestNG] Time taken by [FailedReporter passed=0 failed=0 skipped=0]: 5 ms
[TestNG] Time taken by org.testng.reporters.SuiteHTMLReporter@77556fd: 27 ms
[TestNG] Time taken by org.testng.reporters.XMLReporter@7a7b0070: 3 ms

另外如果程序出现异常 会在项目下test-output/testng-failed.xml 汇整错误信息，方便观察错误类、方法，方便回购测试