在Android上使用PowerMockito模拟静态方法

Question

我正在尝试stub一个静态方法，以便我可以单元测试一个REST Api接口。

我用…

• PowerMockito 1.5(启用静态模拟)
• Roboelectric 1.2(将android的其余部分拔掉)
• JUnit 4.10

运行下面的代码会产生后续的错误

有什么办法可以解决这个问题吗?

    @RunWith(RobolectricTestRunner.class)
    @PrepareForTest({Api.class})
    public class ApiTest extends TestCase {
        @Rule
        public PowerMockRule rule = new PowerMockRule();
        ...
        @Test
        public void testGet() throws Exception {
            Api.Response fakeResponse = PowerMockito.mock(Api.Response.class);
            PowerMockito.when(fakeResponse.getResult()).thenReturn(responseObj);
            mockStatic(Api.class);
            PowerMockito.when(Api.execute(any(HttpRequestBase.class))).thenReturn(fakeResponse);
            Api.get("/v1/contacts/");
        }
    }

然而，在我们调用"Api"之前的静态存根。Get "抛出以下错误…

java.lang.RuntimeException: java.lang.ClassNotFoundException: caught an exception while obtaining a class file for org.powermock.classloading.DeepCloner
    at org.powermock.api.support.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:68)
    at org.powermock.api.support.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:34)
    at org.powermock.classloading.ClassloaderExecutor.createDeepCloner(ClassloaderExecutor.java:106)
    at org.powermock.classloading.ClassloaderExecutor.execute(ClassloaderExecutor.java:88)
    at org.powermock.classloading.ClassloaderExecutor.execute(ClassloaderExecutor.java:78)
    at org.powermock.modules.junit4.rule.PowerMockStatement.evaluate(PowerMockRule.java:49)
    at com.xtremelabs.robolectric.RobolectricTestRunner$1.evaluate(RobolectricTestRunner.java:288)
    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.junit.runner.JUnitCore.run(JUnitCore.java:157)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:77)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:195)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:63)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at com.intellij.rt.execution.application.AppMain.main(AppMain.java:120)
Caused by: java.lang.ClassNotFoundException: caught an exception while obtaining a class file for org.powermock.classloading.DeepCloner
    at javassist.Loader.findClass(Loader.java:360)
    at com.xtremelabs.robolectric.bytecode.RobolectricClassLoader.findClass(RobolectricClassLoader.java:83)
    at javassist.Loader.loadClass(Loader.java:312)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
    at com.xtremelabs.robolectric.bytecode.RobolectricClassLoader.loadClass(RobolectricClassLoader.java:59)
    at java.lang.Class.forName0(Native Method)
    at java.lang.Class.forName(Class.java:247)
    at org.powermock.api.support.ClassLoaderUtil.loadClass(ClassLoaderUtil.java:66)
    ... 24 more
Caused by: com.xtremelabs.robolectric.bytecode.IgnorableClassNotFoundException: msg because of javassist.NotFoundException: org.powermock.classloading.DeepCloner
    at com.xtremelabs.robolectric.bytecode.AndroidTranslator.onLoad(AndroidTranslator.java:92)
    at javassist.Loader.findClass(Loader.java:341)
    ... 31 more

Answer 1

要使用静态mock，您必须使用PowerMockRunner，否则它无法工作。参考文档

如果可能的话，我总是避免静态模拟，因为类加载的复杂性。如果您愿意分享经过测试的代码，也许我可以建议一些解决方法。通常我在类中创建一个使用静态方法的非静态方法，然后在这个非静态方法中调用静态方法。然后，我简单地对被测试的类做一个监视，并且只模拟这个方法。这样我就不需要PowerMock了