单元测试JUnit4 Ctrl + Shift + T

public class Calculator {    public int result = 0;

public int add(int operandl, int operand2) {        result = operandl + operand2;        return result;    }

public int subtract(int operandl, int operand2) {        result = operandl - operand2;        return result;    }

public int multiple(int operandl, int operand2) {        result = operandl * operand2;        for (; ; ) {

}    }

public int divide(int operandl, int operand2) {        result = operandl / 0;        return result;    }

public int getResult() {        return this.result;    }

}

public class CalculatorTest {    public static Calculator cal = new Calculator();

//测试开始前只能被执行一次    @BeforeClass    public static void setUpBeforClass() throws Exception {        System.out.println(" @BeforeClass");

}

//测试结束前只调用一次    @AfterClass    public static void tearDownAfterClass() throws Exception {        System.out.println("@AfterClass");    }

@Before    public void setUp() throws Exception {        System.out.println("测试开始");    }

@After    public void tearDown() throws Exception {        System.out.println("测试结束");    }

@Test    public void testSubstract() {        cal.subtract(4, 2);        assertEquals(2, cal.getResult());//        fail("Not yet implemented");    }

@Test    public void testAdd() {        cal.add(2, 2);        assertEquals(4, cal.getResult());//        fail("Not yet implemented");    }

//忽略执行    @Ignore    public void testMultiply() {        fail("Not yet implemented");

}

//测试用例时间不能超过2s，死循环时间超过2s    @Test(timeout = 2000)    public void testDivide() {        for (; ; ) ;    }

//执行之后抛出异常才成功    @Test(expected = ArithmeticException.class)    public void testDivideByZero() {        cal.divide(4, 0);    }

}