运行JUnit时出现java NullPointerException

Question

在运行JUnit测试时获取NullPointerException。我已经嘲笑了ClientHttpResponse类。不知道我还缺什么

错误：

java.lang.NullPointerException
    at org.springframework.web.client.DefaultResponseErrorHandler.hasError(DefaultResponseErrorHandler.java:75)
    at org.springframework.web.client.DefaultResponseErrorHandler.hasError(DefaultResponseErrorHandler.java:50)
    at com.tss.payhub.template.rest.client.CustomResponseErrorHandler.hasError(CustomResponseErrorHandler.java:20)
    at com.tss.payhub.template.rest.client.test.CustomResponseErrorHandlerTest.testHasError(CustomResponseErrorHandlerTest.java:21)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.lang.reflect.Method.invoke(Method.java:498)
    at org.junit.runners.model.FrameworkMethod$1.runReflectiveCall(FrameworkMethod.java:47)
    at org.junit.internal.runners.model.ReflectiveCallable.run(ReflectiveCallable.java:12)
    at org.junit.runners.model.FrameworkMethod.invokeExplosively(FrameworkMethod.java:44)
    at org.junit.internal.runners.statements.InvokeMethod.evaluate(InvokeMethod.java:17)
    at org.junit.runners.ParentRunner.runLeaf(ParentRunner.java:271)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:70)
    at org.junit.runners.BlockJUnit4ClassRunner.runChild(BlockJUnit4ClassRunner.java:50)
    at org.junit.runners.ParentRunner$3.run(ParentRunner.java:238)
    at org.junit.runners.ParentRunner$1.schedule(ParentRunner.java:63)
    at org.junit.runners.ParentRunner.runChildren(ParentRunner.java:236)
    at org.junit.runners.ParentRunner.access$000(ParentRunner.java:53)
    at org.junit.runners.ParentRunner$2.evaluate(ParentRunner.java:229)
    at org.junit.runners.ParentRunner.run(ParentRunner.java:309)
    at org.junit.runner.JUnitCore.run(JUnitCore.java:160)
    at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68)
    at com.intellij.rt.execution.junit.IdeaTestRunner$Repeater.startRunnerWithArgs(IdeaTestRunner.java:47)
    at com.intellij.rt.execution.junit.JUnitStarter.prepareStreamsAndStart(JUnitStarter.java:242)
    at com.intellij.rt.execution.junit.JUnitStarter.main(JUnitStarter.java:70)

CustomResponseErrorHandlerTest。java

public class CustomResponseErrorHandlerTest {
    @Mock
    ClientHttpResponse response = Mockito.mock(ClientHttpResponse.class);

    @Test
    public void testHasError() throws IOException {
        CustomResponseErrorHandler instance = new CustomResponseErrorHandler();
        boolean blnVal = instance.hasError(response);
        assertTrue(blnVal);
    }
}

CustomResponseErrorHandler。java（测试中的类）

@Component
public class CustomResponseErrorHandler implements ResponseErrorHandler {
    private ResponseErrorHandler errorHandler = new DefaultResponseErrorHandler();

    public boolean hasError(ClientHttpResponse response) throws IOException {
        return errorHandler.hasError(response);
    }
}