Junit的异常测试

方式１：

@Test(expected = IndexOutOfBoundsException.class)

public void empty() {

     new ArrayList<Object>().get(0);

}
解析：
＠Test的注释有一个可选参数expected，它作为Throwable的子类，可以抛出异常。

方式２：
使用try...catch()..

@Test

public void testExceptionMessage() {

    try {

        new ArrayList<Object>().get(0);

        fail("Expected an IndexOutOfBoundsException to be thrown");

    } catch (IndexOutOfBoundsException anIndexOutOfBoundsException) {

        assertThat(anIndexOutOfBoundsException.getMessage(), is("Index: 0, Size: 0"));

    }

}

方式３:
使用ExpectedException规则，此规则可以指示出异常和异常信息。

@Rule

public ExpectedException thrown = ExpectedException.none();

@Test

public void shouldTestExceptionMessage() throws IndexOutOfBoundsException {

    List<Object> list = new ArrayList<Object>();

    thrown.expect(IndexOutOfBoundsException.class);

    thrown.expectMessage("Index: 0, Size: 0");

    list.get(0); // execution will never get past this line

}

方式４：
使用Ｍatchers检查异常

import static org.hamcrest.Matchers.hasProperty;

import static org.hamcrest.Matchers.is;

import static org.hamcrest.Matchers.startsWith;

import javax.ws.rs.NotFoundException;

import javax.ws.rs.core.Response;

import javax.ws.rs.core.Response.Status;

import org.junit.Rule;

import org.junit.Test;

import org.junit.rules.ExpectedException;

public class TestExy {

    @Rule

    public ExpectedException thrown = ExpectedException.none();

    @Test

    public void shouldThrow() {

        TestThing testThing = new TestThing();

        thrown.expect(NotFoundException.class);

        thrown.expectMessage(startsWith("some Message"));

        thrown.expect(hasProperty("response", hasProperty("status", is(404))));

        testThing.chuck();

    }

    private class TestThing {

        public void chuck() {

            Response response = Response.status(Status.NOT_FOUND).entity("Resource not found").build();

            throw new NotFoundException("some Message", response);

        }

    }

}

更多信息点击此链接：
https://github.com/junit-team/junit4/wiki/Exception-testing