如何在log4j中使用AsyncAppender？

Question

如何在log4j中使用AsyncAppender以便将日志消息写入Web服务？我应该创建自己的Appender,它会扩展AsyncAppender或只是将自定义appender附加到AsyncAppender？如果第二个选择正确,我应该在哪里使用AsyncAppender对象？有什么例子吗？

Answer 1

在log4j配置文件中添加AsyncAppender,它将引用一个真正的appender.对于演示:在log4j.xml中将asyncappender添加到console appender

<?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>

Answer 2

我们想使用log4j.AsyncAppender但找不到任何setter方法来在log4j.property文件中附加其他appender.所以我们扩展了log4j.AsyncAppender类并添加了一个setter来添加其他appender.这有助于主程序线程独立于log4j的日志记录操作.详情如下.

log4j条目:

使用log4j File Appender,'fileAppender'定义记录器'com.noPath'.请注意,记录器路径并不重要,因此名称为"com.noPath"

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

通过自定义类com.log.AsyncAppenderHelper定义业务需要的记录器,'com.business',将上一步的File appender,'fileAppender'附加到log4j AsyncAppender,扩展log4j AsyncAppender

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

扩展log4j.AsyncAppender的java类com.log.AsyncAppenderHelper在类路径中可用.

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));
        }

     }
}

Answer 3

回答我自己的问题。

在 log4j 配置文件（通常是 log4j.xml 或 log4j.properties）中，我们应该定义 AsyncAppender ，它将引用真正的附加程序（它可能是我们自己定义的类，就像我的例子一样）。

所以我写了一个WebServiceAppender类，它扩展了AppenderSkeleton并实现了3个抽象方法。主要方法是“append”，它连接到 Web 服务并向其发送所有信息。就是这样。