使用 PowerMockito 模拟文件

Question

我有以下测试代码：

@RunWith(PowerMockRunner.class)
@PrepareForTest({Logger.class, Files.class})
public class TestClass {

  private static final List<String> LIST = new ArrayList<String>() {{
    add("some entry");
  }};
  private static final Path PATH = Paths.get("/tmp/foo");

  @Before
  public void setup() {
    PowerMockito.spy(Files.class);
    PowerMockito.doReturn(LIST).when(Files.class, "readAllLines", PATH, Charset.defaultCharset());
  }

  @Test
  public void test() {}
}

上面的代码在最后一行抛出“NoSuchFileException”。这是堆栈跟踪：

java.nio.file.NoSuchFileException: /tmp/foo at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102) at sun.nio .fs.UnixException.rethrowAsIOException(UnixException.java:107) at sun.nio.fs.UnixFileSystemProvider.newByteChannel(UnixFileSystemProvider.java:214) at java.nio.file.Files.newByteChannel(Files.java:317) at java。 nio.file.Files.newByteChannel(Files.java:363) 在 java.nio.file.spi.FileSystemProvider.newInputStream(FileSystemProvider.java:380) 在 java.nio.file.Files.newInputStream(Files.java:108)在 java.nio.file.Files.newBufferedReader(Files.java:2677) 在 java.nio.file.Files.readAllLines(Files.java:3033) 在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 在 sun.reflect .NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.powermock.reflect.internal .WhiteboxImpl.performMethodInvocation(WhiteboxImpl.java:2014) at org.powermock.reflect.internal.WhiteboxImpl.doInvokeMethod(WhiteboxImpl.java:885) at org.powermock.reflect.internal.WhiteboxImpl.invokeMethod(WhiteboxImpl.java:859) org.powermock.reflect.Whitebox.invokeMethod(Whitebox.java:466) 在 org.powermock.api.mockito.internal.expectation.PowerMockitoStubberImpl.when(PowerMockitoStubberImpl.java:106) 在 TestClass.setup(TestClass.java:29)在 sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) 在 sun.reflect.NativeMethodAccessorImpl。invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at org.junit.internal.runners.MethodRoadie .runBefores(MethodRoadie.java:129) 位于 org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:93) 位于 org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl44RunnerDelegateImpl4(Unit4Runner. :294) 在 org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127) 在 org.powermock.modules.junit4.inockPowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127)executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282) 84) 在 org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49) 在 org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207) 在 org.orgsmodule.orgsmodules .junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146) 在 org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$1.run(PowerMockJUnit44RunnerDelegateImpl.java:146) at 1.run(PowerMockJUnit44RunnerDelegateImpl.java:146)runners.ClassRoadie.runUnprotected(ClassRoadie.java:34) at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:44) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImplUnit44RunnerDelegateImpl.run(PowerDelegateImplUnit4mpl4 java:118) 在 org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:101) 在 org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunnerCommonPowerMockRunnerCommonPowerMockRunnerCommonPower java:53) 在 org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:53) 在 org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:50) 在 org.eclipse .jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38) 在 org.eclipse.jdt.internal.junit.runner。RemoteTestRunner.runTests(RemoteTestRunner.java:467) 在 org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683) 在 org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run( RemoteTestRunner.java:390) 在 org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

我不太明白我在这里做错了什么。

Answer 1

我发现了问题：问题是 Files 是 System 类。

https://github.com/powermock/powermock/wiki/mocksystem