Dubbo拦截器实现的原理,我的理解就是实现或扩展Dubbo自己的Filter接口(LogFilter implements Filter),然后将这个类在配置文件(META-INF/dubbo/com.alibaba.dubbo.rpc.Filter文本文件)中与一个名称对应(logFilter),然后在dubbo配置文件中对需要增加拦截器的bean进行配置。
我在之前自己搭建的消费者当中实现了一个filter
1.Consumer端增加LogFilter类,扩展Filter
package com.mohrss.service;
import com.alibaba.dubbo.rpc.*;
public class LogFilter implements Filter {
public Result invoke(Invoker> invoker, Invocation invocation) throws RpcException {
// TODO Auto-generated method stub
Result result = null;
Long takeTime = 0L;
try{
Long startTime = System.currentTimeMillis();
//before filter
System.out.println("before filter");
result = invoker.invoke(invocation);
if (result.getException() instanceof Exception)
{
throw new Exception(result.getException());
}
takeTime = System.currentTimeMillis() - startTime;
System.out.println("TakeTime: " + takeTime);
//after filter
System.out.println("after filter");
}
catch(Exception e){
e.printStackTrace();
result = new RpcResult(e);
return result;
}
return result;
}
}
2.增加配置文件(META-INF/dubbo/com.alibaba.dubbo.rpc.Filter),给LogFilter类起名。
logFilter=com.mohrss.service.LogFilter
3.将logFilter加入需要进行拦截器配置的配置属性当中。(dubbo-consumer.xml)
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:dubbo="http://code.alibabatech.com/schema/dubbo"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://code.alibabatech.com/schema/dubbo
http://code.alibabatech.com/schema/dubbo/dubbo.xsd ">
这时,启动provider和consumer就可以看到provider和consumer的控制台上分别打印出了调用和拦截信息。
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