@Test(expectedExceptions = )
在测试的时候，某些用例的输入条件，预期结果是代码抛出异常，那么这个时候就需要testNG的异常测试，先看一段会抛出异常的代码
exception.java：
import org.testng.annotations.Test;
public class exception {
@Test
public void testMethod() {
int a = 0;
int b = 10;
System.out.println(b / a);
}
}
运行结果：
FAILED: testMethod
java.lang.ArithmeticException: / by zero
at exception.testMethod(exception.java:9)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
at java.lang.reflect.Method.invoke(Unknown Source)
at org.testng.internal.MethodInvocationHelper.invokeMethod(MethodInvocationHelper.java:74)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:673)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:846)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1170)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
at org.testng.TestRunner.runWorkers(TestRunner.java:1147)
at org.testng.TestRunner.privateRun(TestRunner.java:749)
at org.testng.TestRunner.run(TestRunner.java:600)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:317)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:312)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:274)
at org.testng.SuiteRunner.run(SuiteRunner.java:223)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1039)
at org.testng.TestNG.runSuitesLocally(TestNG.java:964)
at org.testng.TestNG.run(TestNG.java:900)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:110)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:205)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:174) ===============================================
Default test
Tests run: 1, Failures: 1, Skips: 0
===============================================
如果我们的预期结果就是代码抛出异常ArithmeticException，用例通过的话，则通过@Test的expectedExceptions属性，通过该属性指定抛出异常的类，
修改exception.java，添加(expectedExceptions = ArithmeticException.class)：
import org.testng.annotations.Test;
public class exception {
@Test(expectedExceptions = ArithmeticException.class)
public void testMethod() {
int a = 0;
int b = 10;
System.out.println(b / a);
}
}
再次运行，结果通过：
PASSED: testMethod ===============================================
Default test
Tests run: 1, Failures: 0, Skips: 0
===============================================
如果是一个正常的代码，期望抛出异常的话，会怎样呢？
修改exception.java，不会抛出异常：
import org.testng.annotations.Test;
public class exception {
@Test(expectedExceptions = ArithmeticException.class)
public void testMethod() {
int a = 0;
int b = 10;
System.out.println(a / b);
}
}
再次运行，结果失败：
FAILED: testMethod
org.testng.TestException:
Expected exception java.lang.ArithmeticException but got org.testng.TestException:
Method exception.testMethod() should have thrown an exception of class java.lang.ArithmeticException
at org.testng.internal.Invoker.handleInvocationResults(Invoker.java:1416)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1184)
at org.testng.internal.TestMethodWorker.invokeTestMethods(TestMethodWorker.java:125)
at org.testng.internal.TestMethodWorker.run(TestMethodWorker.java:109)
at org.testng.TestRunner.runWorkers(TestRunner.java:1147)
at org.testng.TestRunner.privateRun(TestRunner.java:749)
at org.testng.TestRunner.run(TestRunner.java:600)
at org.testng.SuiteRunner.runTest(SuiteRunner.java:317)
at org.testng.SuiteRunner.runSequentially(SuiteRunner.java:312)
at org.testng.SuiteRunner.privateRun(SuiteRunner.java:274)
at org.testng.SuiteRunner.run(SuiteRunner.java:223)
at org.testng.SuiteRunnerWorker.runSuite(SuiteRunnerWorker.java:52)
at org.testng.SuiteRunnerWorker.run(SuiteRunnerWorker.java:86)
at org.testng.TestNG.runSuitesSequentially(TestNG.java:1039)
at org.testng.TestNG.runSuitesLocally(TestNG.java:964)
at org.testng.TestNG.run(TestNG.java:900)
at org.testng.remote.RemoteTestNG.run(RemoteTestNG.java:110)
at org.testng.remote.RemoteTestNG.initAndRun(RemoteTestNG.java:205)
at org.testng.remote.RemoteTestNG.main(RemoteTestNG.java:174)
Caused by: org.testng.TestException:
Method exception.testMethod() should have thrown an exception of class java.lang.ArithmeticException
at org.testng.internal.Invoker.handleInvocationResults(Invoker.java:1442)
at org.testng.internal.Invoker.invokeMethod(Invoker.java:722)
at org.testng.internal.Invoker.invokeTestMethod(Invoker.java:846)
at org.testng.internal.Invoker.invokeTestMethods(Invoker.java:1170)
... 17 more ===============================================
Default test
Tests run: 1, Failures: 1, Skips: 0
===============================================