我在这里没有问题。使用Mockito API的以下代码，我做到了：
public class CodeWithPrivateMethod { public void meaningfulPublicApi() { if (doTheGamble("Whatever", 1 << 3)) { throw new RuntimeException("boom"); } } private boolean doTheGamble(String whatever, int binary) { Random random = new Random(System.nanoTime()); boolean gamble = random.nextBoolean(); return gamble; }}这是JUnit测试：
import org.junit.Test;import org.junit.runner.RunWith;import org.powermock.api.mockito.PowerMockito;import org.powermock.core.classloader.annotations.PrepareForTest;import org.powermock.modules.junit4.PowerMockRunner;import static org.mockito.Matchers.anyInt;import static org.mockito.Matchers.anyString;import static org.powermock.api.mockito.PowerMockito.when;import static org.powermock.api.support.membermodification.MemberMatcher.method;@RunWith(PowerMockRunner.class)@PrepareForTest(CodeWithPrivateMethod.class)public class CodeWithPrivateMethodTest { @Test(expected = RuntimeException.class) public void when_gambling_is_true_then_always_explode() throws Exception { CodeWithPrivateMethod spy = PowerMockito.spy(new CodeWithPrivateMethod()); when(spy, method(CodeWithPrivateMethod.class, "doTheGamble", String.class, int.class)) .withArguments(anyString(), anyInt()) .thenReturn(true); spy.meaningfulPublicApi(); }}
