java - 使用 JMockit 模拟 ResourceLoading

Question

我的应用程序使用保存配置设置的单例。这是代码:

private PropertiesSingleton() throws Exception {
    InputStream appstream = this.getClass().getClassLoader()
            .getResourceAsStream("application.properties");
    props = new Properties();
    try {
        props.load(appstream);
    } catch (IOException e) {
        logger.log(Log.FATAL,
                "Cannot find application.properties in classpath.", e);
        throw e;
    }
}

通常我的应用程序在容器内运行。对于我的单元测试，我必须使 application.properties 可供加载。我尝试过这样的:

@Before
public void init() throws Exception {


    final FileInputStream inStream = new FileInputStream("../path/to/config/application.properties");
    new NonStrictExpectations(ClassLoader.class) {
        {
            String.class.getClassLoader().getResourceAsStream("application.properties"); result = inStream;
        }
    };
}

测试不会启动，但会打印此堆栈跟踪:

java.lang.VerifyError
at sun.instrument.InstrumentationImpl.redefineClasses0(Native Method)
at de.lpm.ejb.archiving.ArchiveHandlerBeanTest$2.<init>(ArchiveHandlerBeanTest.java:50)
at de.lpm.ejb.archiving.ArchiveHandlerBeanTest.init(ArchiveHandlerBeanTest.java:50)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.lang.reflect.Method.invoke(Method.java:597)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.lang.reflect.Method.invoke(Method.java:597)
at org.eclipse.jdt.internal.junit4.runner.JUnit4TestReference.run(JUnit4TestReference.java:46)
at org.eclipse.jdt.internal.junit.runner.TestExecution.run(TestExecution.java:38)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:467)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.runTests(RemoteTestRunner.java:683)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.run(RemoteTestRunner.java:390)
at org.eclipse.jdt.internal.junit.runner.RemoteTestRunner.main(RemoteTestRunner.java:197)

Answer 1

我相信模拟类加载器根本不可能，因为它首先存在。在类加载器出现之前你不能做任何事情。因此，请尝试模拟调用者，而不是类加载器。