我发现 cobertura-maven-plugin 2.6 和 jmockit 1.8 之间存在奇怪的交互。我们的生产代码中的一个特定模式有一个带有许多静态方法的类,这些静态方法有效地包装了一个像单例一样的不同类。为这些类编写单元测试进展顺利,直到我尝试使用 cobertura 运行覆盖率报告时,出现了以下错误:
java.lang.ExceptionInInitializerError
at java.lang.reflect.Constructor.newInstance(Constructor.java:526)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.maven.surefire.junit4.JUnit4Provider.execute(JUnit4Provider.java:252)
at org.apache.maven.surefire.junit4.JUnit4Provider.executeTestSet(JUnit4Provider.java:141)
at org.apache.maven.surefire.junit4.JUnit4Provider.invoke(JUnit4Provider.java:112)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.lang.reflect.Method.invoke(Method.java:606)
at org.apache.maven.surefire.util.ReflectionUtils.invokeMethodWithArray(ReflectionUtils.java:189)
at org.apache.maven.surefire.booter.ProviderFactory$ProviderProxy.invoke(ProviderFactory.java:165)
at org.apache.maven.surefire.booter.ProviderFactory.invokeProvider(ProviderFactory.java:85)
at org.apache.maven.surefire.booter.ForkedBooter.runSuitesInProcess(ForkedBooter.java:115)
at org.apache.maven.surefire.booter.ForkedBooter.main(ForkedBooter.java:75)
Caused by: java.lang.NullPointerException
at com.example.foo.MySingleton.<clinit>(MySingleton.java:7)
... 13 more
这会导致NoClassDefFoundError
并且无法初始化单例类。这是一个完整的 SSCCE(我能得到的最短的),它复制了错误;第 7 行MySingleton
is Logger.getLogger()
.
这里是“单例”...
package com.example.foo;
import org.apache.log4j.Logger;
public class MySingleton {
private static final Logger LOG = Logger.getLogger(MySingleton.class);
private boolean inited = false;
private Double d;
MySingleton() {
}
public boolean isInited() {
return inited;
}
public void start() {
inited = true;
}
public double getD() {
return d;
}
}
还有静态类...
package com.example.foo;
import org.apache.log4j.Logger;
public class MyStatic {
private static final Logger LOGGER = Logger.getLogger(MyStatic.class);
private static MySingleton u = new MySingleton();
public static double getD() {
if (u.isInited()) {
return u.getD();
}
return 0.0;
}
}
以及打破一切的测试......
package com.example.foo;
import mockit.Expectations;
import mockit.Mocked;
import mockit.Tested;
import org.junit.Test;
public class MyStaticTest {
@Tested MyStatic myStatic;
@Mocked MySingleton single;
@Test
public void testThatBombs() {
new Expectations() {{
single.isInited(); result = true;
single.getD(); /*result = 1.2;*/
}};
// Deencapsulation.invoke(MyStatic.class, "getD");
MyStatic.getD();
}
}
和 Maven pom:
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>com.example.foo</groupId>
<artifactId>test</artifactId>
<version>0.0.1-SNAPSHOT</version>
<name>Test</name>
<dependencies>
<dependency>
<groupId>log4j</groupId>
<artifactId>log4j</artifactId>
<version>1.2.16</version>
</dependency>
<dependency>
<groupId>org.jmockit</groupId>
<artifactId>jmockit</artifactId>
<version>1.8</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<pluginManagement>
<plugins>
<plugin>
<groupId>org.codehaus.mojo</groupId>
<artifactId>cobertura-maven-plugin</artifactId>
<version>2.6</version>
</plugin>
</plugins>
</pluginManagement>
</build>
</project>
总结一下:运行普通单元测试时(mvn clean test
),上面测试就好了;当与 cobertura 一起运行时(mvn clean cobertura:cobertura
)它会抛出顶部显示的一组令人讨厌的异常。显然是某个地方的错误,但是是谁的?