如何在log4j中使用AsyncAppender？[英] How to use AsyncAppender in log4j?

问题描述

How to use AsyncAppender in log4j in order to write log message to the web service? Should I create my own Appender which would extend AsyncAppender or just attach custom appenders to the AsyncAppender? If the second choice is correct, where should I take the AsyncAppender object? Is there any example?

推荐答案

Answering my own question.

In the log4j config file(usually it's log4j.xml or log4j.properties) we should define AsyncAppender which would refer to a real appender(it may be our own defined class like in my case).

So I wrote a WebServiceAppender class which extends AppenderSkeleton and implements 3 abstract methods. The main method is "append" which connects to the web service and sends all the information to it. That's it.

其他推荐答案

Add AsyncAppender in log4j config file which will refer to a real appender. For demo: adding asyncappender to console appender in log4j.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE log4j:configuration SYSTEM "log4j.dtd" >
<log4j:configuration>
<appender name="console" class="org.apache.log4j.ConsoleAppender">
    <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="[%p] %d{dd MMM hh:mm:ss aa} %t [%l] %m%n"/>
    </layout>
</appender>
<appender name="async" class="org.apache.log4j.AsyncAppender">
    <param name="BufferSize" value="500"/>
    <appender-ref ref="console"/>
</appender>
<root>
    <priority value="all"></priority>
    <appender-ref ref="async"/>
</root>
</log4j:configuration>

其他推荐答案

We wanted to use log4j.AsyncAppender but couldn't find any setter methods to attach other appenders at the log4j.property file. So we extended the log4j.AsyncAppender class and added a setter to add other appenders. This has helped the main program thread to be independent of log4j's logging operation. The details below.

log4j entry:

Define a logger 'com.noPath' with log4j File Appender, 'fileAppender'. Note that the logger path is immaterial and hence the name 'com.noPath'

log4j.logger.com.noPath=DEBUG,fileAppender
log4j.appender.fileAppender=org.apache.log4j.RollingFileAppender
log4j.appender.fileAppender.File=c:/test.log

Define the logger that business needs, 'com.business', Attach the File appender of previous step, 'fileAppender', to the log4j AsyncAppender through a custom class com.log.AsyncAppenderHelper which extends log4j AsyncAppender

log4j.logger.com.business=DEBUG,asyncLog
log4j.appender.asyncLog=com.log.AsyncAppenderHelper
log4j.appender.asyncLog.appenderFromLogger=com.noPath

The java class com.log.AsyncAppenderHelper extending log4j.AsyncAppender, have it available in the class path.

package com.log
import java.util.Enumeration;
import org.apache.log4j.Appender;
import org.apache.log4j.AsyncAppender;
import org.apache.log4j.Logger;

/*
 * This class helps configure to AsyncAppender from log4j as part of log4j.properties
 * You can inject other appenders to AsyncAppender using the AsyncAppenderHelper
 * This would free up the main program thread to be independent of log4j's logging operation
 * @Author http://www.linkedin.com/in/jobypgeorge
 */

public class AsyncAppenderHelper extends AsyncAppender{

    public AsyncAppenderHelper(){
        super();
    }

    public void setAppenderFromLogger(String name){
        Logger l = Logger.getLogger(name);

        Enumeration<Appender> e = l.getAllAppenders();

        while(e.hasMoreElements()){
             Appender a = e.nextElement();
             this.addAppender(a);
             System.out.println("The newAppender "+a.getName() +" attach status "+this.isAttached(a));
        }

     }
}