Java 使用PowerMock模拟枚举时静态字段为Null

我已经编写了一个线程池，但无法为该类编写Junits（PowerMock）

public enum ThreadPool {
INSTANCE;

private static final String THREAD_POOL_SIZE = "threadpool.objectlevel.size";
private static TPropertyReader PROP_READER = new PropertyReader();
private final ExecutorService executorService;
private static final ILogger LOGGER = LoggerFactory
        .getLogger(ReportExecutorObjectLevelThreadPool.class.getName());

ThreadPool() {
    loadProperties();
    int no_of_threads = getThreadPoolSize();
    executorService = Executors.newFixedThreadPool(no_of_threads);

}

public void submitTask(Runnable task) {
    executorService.execute(task);
}

private static void loadProperties() {
    try {
        PROP_READER.loadProperties("Dummy");
    } catch (final OODSystemException e) {
        LOGGER.severe("Loading properties for app failed!");
    }
}

private int getThreadPoolSize() {
    return Integer.valueOf(PROP_READER
            .getProperty(THREAD_POOL_SIZE));
}
}

在模拟这个类时，我在PROP_READER.loadProperties（“DUMMY”）行中得到了NullPointerException

我的测试用例是：-

PowerMockito.whenNew(PropertyReader.class).withNoArguments().thenReturn(mockPropertyReader);
PowerMockito.doNothing().when( mockPropertyReader,"loadProperties",anyString());
mockStatic(ThreadPool.class);

---

首先，您需要设置枚举的内部状态，因为枚举是最终类 枚举的实例将在类加载时加载

ThreadPool mockInstance = mock(ThreadPool .class);
Whitebox.setInternalState(ThreadPool.class, "INSTANCE", mockInstance);

然后

然后嘲笑

doNothing().when(mockInstance).loadProperties(any(String.class));

不要忘记将以下注释添加到测试中

@RunWith(PowerMockRunner.class)
@PrepareForTest({ThreadPool.class})

如果仍然不起作用，您需要查看需要在内部状态下设置的类中的哪个成员

@RunWith(PowerMockRunner.class)
@PrepareForTest({ThreadPool.class})