PowerMockito（与 Mockito）因 ExceptionInInitializerError 而失败

Question

我们正在使用 Powermockito 和 Mockito 来模拟一些静态 classes。好像每次都会抛出java.lang.ExceptionInInitializerError。

你能帮我确定问题出在哪里吗？

Javaclass测试中

package com.myproject.myproduct.search.domain;
import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;

public class MyQueryBuilder {

    public MultiMatchQueryBuilder getMultiMatchQueryBuilder() {
        MultiMatchQueryBuilder builder = QueryBuilders.multiMatchQuery("term", "field1");
        builder.field("field1",200.9f);
        return builder;
    }
}

使用 Powermock runner 进行 Junit 测试

package com.myproject.myproduct.search.domain;

import org.elasticsearch.index.query.MultiMatchQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
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;

@RunWith(PowerMockRunner.class)
@PrepareForTest(QueryBuilders.class)
public class MyQueryBuilderTest {

    private MyQueryBuilder myQueryBuilder;

    @Test
    public void test() {
        PowerMockito.mockStatic(QueryBuilders.class);
        MultiMatchQueryBuilder builder = PowerMockito.mock(MultiMatchQueryBuilder.class);
    }
}

就是这样。一旦我尝试模拟，测试代码就不起作用 MultiMatchQueryBuilder.

这是例外情况：

java.lang.ExceptionInInitializerError at org.elasticsearch.common.logging.DeprecationLogger.(DeprecationLogger.java:138) at org.elasticsearch.common.ParseField.(ParseField.java:35) at org.elasticsearch.index.query.AbstractQueryBuilder.(AbstractQueryBuilder.java:53) at sun.reflect.GeneratedSerializationConstructorAccessor7.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Constructor.java:423) at org.objenesis.instantiator.sun.SunReflectionFactoryInstantiator.newInstance(SunReflectionFactoryInstantiator.java:40) at org.objenesis.ObjenesisBase.newInstance(ObjenesisBase.java:59) at org.mockito.internal.creation.jmock.ClassImposterizer.createProxy(ClassImposterizer.java:128) at org.mockito.internal.creation.jmock.ClassImposterizer.imposterise(ClassImposterizer.java:63) at org.powermock.api.mockito.internal.mockcreation.MockCreator.createMethodInvocationControl(MockCreator.java:111) at org.powermock.api.mockito.internal.mockcreation.MockCreator.mock(MockCreator.java:60) at org.powermock.api.mockito.PowerMockito.mock(PowerMockito.java:143) at com.spartasystems.stratas.search.domain.MyQueryBuilderTest.testBoostSetProperly(MyQueryBuilderTest.java:22) 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.internal.runners.TestMethod.invoke(TestMethod.java:68) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:310) at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:88) at org.junit.internal.runners.MethodRoadie.runBeforesThenTestThenAfters(MethodRoadie.java:96) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.executeTest(PowerMockJUnit44RunnerDelegateImpl.java:294) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTestInSuper(PowerMockJUnit47RunnerDelegateImpl.java:127) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit47RunnerDelegateImpl$PowerMockJUnit47MethodRunner.executeTest(PowerMockJUnit47RunnerDelegateImpl.java:82) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl$PowerMockJUnit44MethodRunner.runBeforesThenTestThenAfters(PowerMockJUnit44RunnerDelegateImpl.java:282) at org.junit.internal.runners.MethodRoadie.runTest(MethodRoadie.java:86) at org.junit.internal.runners.MethodRoadie.run(MethodRoadie.java:49) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.invokeTestMethod(PowerMockJUnit44RunnerDelegateImpl.java:207) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.runMethods(PowerMockJUnit44RunnerDelegateImpl.java:146) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:120) at org.junit.internal.runners.ClassRoadie.runUnprotected(ClassRoadie.java:33) at org.junit.internal.runners.ClassRoadie.runProtected(ClassRoadie.java:45) at org.powermock.modules.junit4.internal.impl.PowerMockJUnit44RunnerDelegateImpl.run(PowerMockJUnit44RunnerDelegateImpl.java:122) at org.powermock.modules.junit4.common.internal.impl.JUnit4TestSuiteChunkerImpl.run(JUnit4TestSuiteChunkerImpl.java:104) at org.powermock.modules.junit4.common.internal.impl.AbstractCommonPowerMockRunner.run(AbstractCommonPowerMockRunner.java:53) at org.powermock.modules.junit4.PowerMockRunner.run(PowerMockRunner.java:53) at org.junit.runner.JUnitCore.run(JUnitCore.java:160) at com.intellij.junit4.JUnit4IdeaTestRunner.startRunnerWithArgs(JUnit4IdeaTestRunner.java:68) at com.intellij.rt.execution.junit.IdeaTestRunner$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) Caused by: java.lang.NullPointerException at org.elasticsearch.Build.(Build.java:47) ... 41 more

Process finished with exit code 255

注：

实际底层elasticsearchclasses的源码可以在这里找到

https://github.com/elastic/elasticsearch/blob/master/core/src/main/java/org/elasticsearch/index/query/QueryBuilders.java

和

https://github.com/elastic/elasticsearch/blob/master/core/src/main/java/org/elasticsearch/index/query/MultiMatchQueryBuilder.java

Answer 1

使用模拟调用时 org.elasticsearch.Build#getElasticsearchCodebase

Build.class.getProtectionDomain().getCodeSource().getLocation()

returns null因为代码没有位置（cglib生成的动态方法。）

所以当 initializing org.elasticsearch.Build 在你的模拟代码中使用

final URL url = getElasticsearchCodebase(); // url is null
final String urlStr = url.toString(); // null pointer exception.

当然，模拟不会成功并抛出 ExceptionInInitializerError，这表明在评估静态初始化程序或静态变量的初始化程序期间发生异常。

---

您可以使用以下代码轻松重现此异常：

@RunWith(PowerMockRunner.class)
@PrepareForTest({QueryBuilders.class})
public class MyQueryBuilderTest {

    @Test
    public void test() {
        final Build current = Build.CURRENT;
    }

}