java - 在方法内部调用方法时模拟异常

Question

我有这段代码，我想在调用 try block 内的 close 方法时用mockito抛出 IOException

public static void cleanup(Logger log, Closeable... closeables) {
        for (Closeable c : closeables) {
            if (c != null) {
                try {
                    c.close();
                } catch (IOException e) {
                    if (log != null) {
                        log.warn("Exception in closing " + c, e);
                    }
                }
            }
        }
    }

这是我在测试方法中尝试过的，但显然它不起作用:

OutputStream outputStream = Mockito.mock(OutputStream.class);
doThrow(new IOException()).when(outputStream).close();

cleanup(log, closeables);

我怎样才能实现我的目标？谢谢!

Answer 1

您需要确保将模拟作为第二个参数传递给cleanup方法。

以下测试对我有用:

    @Test
    public void testException() throws IOException {
        OutputStream outputStream = Mockito.mock(OutputStream.class);
        doThrow(new IOException()).when(outputStream).close();
        cleanup(log, outputStream);

        Mockito.verify(outputStream, times(1)).close(); // make sure #close method is called once
    }

cleanup 方法看起来是正确的。无需更改。