Dubbo extension uses interceptor

Reference: http://www.cnblogs.com/lizo/p/6701896.html

http://wely.iteye.com/blog/2304718

Take the interceptor as an example to illustrate

<!-- 在xml配置文件中设置 -->
<dubbo:reference filter="xxx,yyy" /> <!-- 消费方调用过程拦截 -->
<dubbo:consumer filter="xxx,yyy"/> <!-- 消费方调用过程缺省拦截器，将拦截所有reference -->
<dubbo:service filter="xxx,yyy" /> <!-- 提供方调用过程拦截 -->
<dubbo:provider filter="xxx,yyy"/> <!-- 提供方调用过程缺省拦截器，将拦截所有service -->
dubbo扩展配置文件
src
 |-main
    |-java
        |-com
            |-xxx
                |-XxxFilter.java (实现Filter接口)
    |-resources
        |-META-INF
            |-dubbo
                |-com.alibaba.dubbo.rpc.Filter (纯文本文件，内容为：xxx=com.xxx.XxxFilter)
//扩展类
package com.xxx;
 
import com.alibaba.dubbo.rpc.Filter;
import com.alibaba.dubbo.rpc.Invoker;
import com.alibaba.dubbo.rpc.Invocation;
import com.alibaba.dubbo.rpc.Result;
import com.alibaba.dubbo.rpc.RpcException;
 
 
public class XxxFilter implements Filter {
    public Result invoke(Invoker<?> invoker, Invocation invocation) throws RpcException {
        // before filter ...
        Result result = invoker.invoke(invocation);
        // after filter ...
        return result;
    }
}