PowerMockito（with Mockito）因ExceptionInInitializerError而失败

Question

我们正在使用Powermockito和Mockito来模拟一些静态类。似乎每次都会抛出java.lang.ExceptioninInitializerError。

你能帮我找出问题出在哪里吗？

测试中的Java类

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);
    }
}

进程已完成，退出代码为255

注：

实际底层elasticsearch类的源代码可以在这里找到

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

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()

返回null，因为代码没有位置（由cglib生成的动态方法。）

因此，在模拟代码使用的过程中初始化org.elasticsearch.build时

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

当然，模拟将不会成功，并抛出ExceptionInitializerError，这表示在计算静态初始值设定项或静态变量的初始值设定项期间发生了异常。

您可以使用以下代码轻松地再现此异常：

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

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

}