聊聊dubbo的ClassLoaderFilter

@Activate(group = CommonConstants.PROVIDER, order = -30000)
public class ClassLoaderFilter implements Filter {
​
    @Override
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        ClassLoader ocl = Thread.currentThread().getContextClassLoader();
        Thread.currentThread().setContextClassLoader(invoker.getInterface().getClassLoader());
        try {
            return invoker.invoke(invocation);
        } finally {
            Thread.currentThread().setContextClassLoader(ocl);
        }
    }
​
}

public class ClassLoaderFilterTest {
​
    private ClassLoaderFilter classLoaderFilter = new ClassLoaderFilter();
​
    @Test
    public void testInvoke() throws Exception {
        URL url = URL.valueOf("test://test:11/test?accesslog=true&group=dubbo&version=1.1");
​
        String path = DemoService.class.getResource("/").getPath();
        final URLClassLoader cl = new URLClassLoader(new java.net.URL[]{new java.net.URL("file:" + path)}) {
            @Override
            public Class<?> loadClass(String name) throws ClassNotFoundException {
                try {
                    return findClass(name);
                } catch (ClassNotFoundException e) {
                    return super.loadClass(name);
                }
            }
        };
        final Class<?> clazz = cl.loadClass(DemoService.class.getCanonicalName());
        Invoker invoker = new MyInvoker(url) {
            @Override
            public Class getInterface() {
                return clazz;
            }
​
            @Override
            public Result invoke(Invocation invocation) throws RpcException {
                Assertions.assertEquals(cl, Thread.currentThread().getContextClassLoader());
                return null;
            }
        };
        Invocation invocation = Mockito.mock(Invocation.class);
​
        classLoaderFilter.invoke(invoker, invocation);
    }
}