Question

我正在对以下课程进行单元测试：

public class FileClass {

    public void funcB() {
        try {
            throw new ClassNotFoundException();
        }
        catch( ClassNotFoundException e ) {

        }
    }
}

使用如下所示的Mockito代码：

public class TestFileClass {

    @Test(expected=ClassNotFoundException.class)
    public void testFuncB() {
        FileClass fc = Mockito.spy(new FileClass());
        fc.funcB();
    }

}

但由于以下错误导致测试失败：

java.lang.AssertionError: Expected exception: java.lang.ClassNotFoundException
    at org.junit.internal.runners.statements.ExpectException.evaluate(ExpectException.java:35)
    at org.junit.internal.runners.statements.RunBefores.evaluate(RunBefores.java:28)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:263)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:68)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:47)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:231)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:60)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:50)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:222)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:300)
    at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50)
    at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
    at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

我也试过PowerMockito但又失败了。有这个错误的任何线索？在我看来，我无法对ClassNotFoundException进行任何测试？

Answer 1

funcB没有抛出异常，因为你是在funcB的主体内捕获它。

Answer 2

方法funcB（）应抛出异常，而不是捕获它。代码低于测试工作：

public class FileClass {

public void funcB() throws ClassNotFoundException {
    //try {
        throw new ClassNotFoundException();
    //} catch ( ClassNotFoundException e) {

    //}
}

}

Mockito测试：

public class TestFileClass {

@Test(expected = ClassNotFoundException.class)
public void testFuncB() throws ClassNotFoundException {
    FileClass fc = Mockito.spy(new FileClass());
    fc.funcB();
}

}

Answer 3

我认为描述测试异常的方法（@Test中的预期注释）并不是最优雅的解决方案 - 它会给出/当/然后约定

最佳选择是catch-exception库

http://code.google.com/p/catch-exception/

Answer 4

很好的抓住异常。但是assertj（http://joel-costigliola.github.io/assertj/）对异常检查有更好的支持

assertThatThrownBy(new DummyService()::someMethod) 
            .isInstanceOf(RuntimeException.class)
            .hasMessage("Runtime exception occurred")
            .hasNoCause();

我怎么能用Mockito测试ClassNotFoundException？

4 个答案: