7-log4j2之自定义Appender

一、添加Maven依赖

<dependencies>

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-api</artifactId>

            <version>${log4j.version}</version>

        </dependency>

        <dependency>

            <groupId>org.apache.logging.log4j</groupId>

            <artifactId>log4j-core</artifactId>

            <version>${log4j.version}</version>

        </dependency>

  </dependencies>

二、自定义Appender

package com.weidai.zm.logger;

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.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 java.io.Serializable;

/**

 * @author : zhangyanqing

 * @time : 2017/12/10

 * @desc : 自定义Appender

 */

@Plugin(name="ConsoleArea", category = "core",elementType = "appender", printObject = true)

public class MyAppender extends AbstractAppender{

    public MyAppender(final String name, final Filter filter, final Layout<? extends Serializable> layout, final boolean ignoreExceptions) {

        super(name, filter, layout,ignoreExceptions);

    }

    @Override

    public void append(LogEvent logEvent) {

        System.out.println("[My Appender] "+logEvent.getLoggerName()+"=>"+logEvent.getMessage());

    }

    @PluginFactory

    public static MyAppender 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 MyAppender(name, filter, layout, ignoreExceptions);

    }

}

三、log4j2.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>

<Configuration status="WARN">

    <properties>

        <Property name="console-pattern">%d{yyyy-MM-dd HH:mm:ss.SSS} [%t] [%level] %logger{36} - %msg%n</Property>

    </properties>

    <Appenders>

        <Console name="Console" target="SYSTEM_OUT">

            <PatternLayout pattern="${console-pattern}" />

        </Console>

    </Appenders>

    <Loggers>

        <Root level="info">

            <AppenderRef ref="Console" />

        </Root>

    </Loggers>

</Configuration>

四、测试代码

import org.apache.logging.log4j.LogManager;

import org.apache.logging.log4j.Logger;

/**

 * @author : zhangyanqing

 * @time : 2017/12/9

 * @desc : 根控制器日志测试

 */

public class ConsoleLoggerTest {

    public static final Logger LOGGER = LogManager.getLogger(LogManager.ROOT_LOGGER_NAME);

    public static void main(String[] args){

        LOGGER.trace("trace level");

        LOGGER.debug("debug level");

        LOGGER.info("info level");

        LOGGER.warn("warn level");

        LOGGER.error("error level");

        LOGGER.fatal("fatal level");

    }

}