import com.alibaba.dubbo.examples.callback.api.CallbackService; //导入依赖的package包/类
public static void main(String[] args) throws Exception {
    String config = CallbackConsumer.class.getPackage().getName().replace('.', '/') + "/callback-consumer.xml";
    ClassPathXmlApplicationContext context = new ClassPathXmlApplicationContext(config);
    context.start();
    CallbackService callbackService = (CallbackService) context.getBean("callbackService");
    callbackService.addListener("foo.bar", new CallbackListener() {
        public void changed(String msg) {
            System.out.println("callback1:" + msg);
        }
    });
    System.in.read();
}