Log4j2 自定义 Appender

摘要: 自定义log4j2 的Appender 将日志输出到指定weizhi

虽然log4j2 自带了很多种Appender 但是有时候避免不了不是自己想要的，这时候我们就需要自定义Appender，使日志输出到我们指定的位置，废话少说，上菜！

package com.hbzx.log;

import java.io.Serializable;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReadWriteLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;

import org.apache.logging.log4j.core.Filter;
import org.apache.logging.log4j.core.Layout;
import org.apache.logging.log4j.core.LogEvent;
import org.apache.logging.log4j.core.appender.AbstractAppender;
import org.apache.logging.log4j.core.appender.AppenderLoggingException;
import org.apache.logging.log4j.core.config.plugins.Plugin;
import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
import org.apache.logging.log4j.core.config.plugins.PluginElement;
import org.apache.logging.log4j.core.config.plugins.PluginFactory;
import org.apache.logging.log4j.core.layout.PatternLayout;

import com.hbzx.frame.MainFrame;

/**
* 自定义Appender，继承 AbstractAppender 只需要覆盖自已想要的方法即可<br>
* 类上面的注解是用来设置配置文件中的标签。
*/
@Plugin(name = "TextArea", category = "Core", elementType = "appender", printObject = true)
public class TextAreaAppender extends AbstractAppender {

/**
* @fields serialVersionUID
*/
private static final long serialVersionUID = -830237775522429777L;
private final ReadWriteLock rwLock = new ReentrantReadWriteLock();
private final Lock readLock = rwLock.readLock();

//需要实现的构造方法，直接使用父类就行
protected TextAreaAppender(final String name, final Filter filter, final Layout<? extends Serializable> layout,
final boolean ignoreExceptions) {
super(name, filter, layout, ignoreExceptions);
}

@Override
public void append(LogEvent event) {
readLock.lock();
try {
final byte[] bytes = getLayout().toByteArray(event);//日志二进制文件，输出到指定位置就行
//下面这个是要实现的自定义逻辑
MainFrame.log(new String(bytes));
} catch (Exception ex) {
if (!ignoreExceptions()) {
throw new AppenderLoggingException(ex);
}
} finally {
readLock.unlock();
}
}

// 下面这个方法可以接收配置文件中的参数信息
@PluginFactory
public static TextAreaAppender createAppender(@PluginAttribute("name") String name,
@PluginElement("Filter") final Filter filter,
@PluginElement("Layout") Layout<? extends Serializable> layout,
@PluginAttribute("ignoreExceptions") boolean ignoreExceptions) {
if (name == null) {
LOGGER.error("No name provided for MyCustomAppenderImpl");
return null;
}
if (layout == null) {
layout = PatternLayout.createDefaultLayout();
}
return new TextAreaAppender(name, filter, layout, ignoreExceptions);
}

}

接下来就是配置文件中的信息了！

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="info" packages="com.hbzx.log">
<Properties>
<Property name="filePath">C:/logs/project.log</Property>
</Properties>

<Appenders>
<!--这个输出控制台的配置 -->
<Console name="console" target="SYSTEM_OUT">
<!--控制台只输出level及以上级别的信息（onMatch），其他的直接拒绝（onMismatch） -->
<ThresholdFilter level="DEBUG" onMatch="ACCEPT" onMismatch="DENY" />
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%-5p]  %c {%F:%L} - %m%n" />
</Console>

<File  name="logFile" fileName="${filePath}">
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%-5p]  %c {%F:%L} - %m%n" />
</File>

<!-- 这个就是自定义的Appender -->
<TextArea name="textarea">
<PatternLayout pattern="%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%-5p] {%F:%L} - %m%n" />
</TextArea>
</Appenders>
<Loggers>
<logger name="com.hbzx" level="debug" />
<logger name="org.apache.http" level="info" />
<logger name="org.apache.commons" level="info" />
<logger name="io.netty" level="info" />
<logger name="org.asynchttpclient" level="info" />

<Root level="debug">
<AppenderRef ref="console" />
<AppenderRef ref="logFile" />
<AppenderRef ref="textarea" />
</Root>
</Loggers>
</Configuration>