SpringBoot | 第二十五章：日志管理之自定义Appender

前言

log4j2

logback

Appender

Appender

log4j2

logback

Appender

一点知识

Appender

log4j2

logback

Appender

log4j2自带Appender

Appender

logback自带Appender

log4j2

自定义Appender

Appender

log4j2

appender

final

log4j2自定义Appender

AbstractAppender

MyLog4j2Appender.java

/**
* 自定义log4j2输出源，简单的输出到控制台
* @author oKong
*
*/
//这里的 MyLog4j2 对应就是 xml中，
/**
*
*  <appenders>
*     <MyLog4j2 name="customAppender" printString="一枚趔趄的猿">
*     </MyLog4j2>
*  </appenders>
*
*/
@Plugin(name = "MyLog4j2", category = "Core", elementType = "appender", printObject = true)
public class MyLog4j2Appender extends AbstractAppender {

String printString;
/**
*构造函数 可自定义参数 这里直接传入一个常量并输出
*
*/
protected MyLog4j2Appender(String name, Filter filter, Layout<? extends Serializable> layout,String printString) {
super(name, filter, layout);
this.printString = printString;
}

@Override
public void append(LogEvent event) {
if (event != null && event.getMessage() != null) {
// 此处自定义实现输出
// 获取输出值：event.getMessage().toString()
// System.out.print(event.getMessage().toString());
// 格式化输出
System.out.print(printString + "：" + getLayout().toSerializable(event));
}

}

/**  接收配置文件中的参数
*
* @PluginAttribute 字面意思都知道，是xml节点的attribute值，如<oKong name="oKong"></oKong> 这里的name 就是 attribute
* @PluginElement：表示xml子节点的元素，
* 如
*     <oKong name="oKong">
*         <PatternLayout pattern="[%d{HH:mm:ss:SSS}] [%p] - %l - %m%n"/>
*     </oKong>
*   其中，PatternLayout就是 的 Layout，其实就是{@link Layout}的实现类。
*/
@PluginFactory
public static MyLog4j2Appender createAppender(
@PluginAttribute("name") String name,
@PluginElement("Filter") final Filter filter,
@PluginElement("Layout") Layout<? extends Serializable> layout,
@PluginAttribute("printString") String printString) {

if (name == null) {
LOGGER.error("no name defined in conf.");
return null;
}
//默认使用 PatternLayout
if (layout == null) {
layout = PatternLayout.createDefaultLayout();
}

return new MyLog4j2Appender(name, filter, layout, printString);
}

@Override
public void start() {
System.out.println("log4j2-start方法被调用");
super.start();
}

@Override
public void stop() {
System.out.println("log4j2-stop方法被调用");
super.stop();
}
}

@Plugin

log4j2-spring.xml

append()

createAppender()

log4j2-spring.xml

log4j2-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration status="WARN" monitorInterval="30" packages="cn.lqdev.learning">
<!--定义appenders-->
<appenders>
<MyLog4j2 name="oKong" printString="一枚趔趄的猿(log4j2)">
<!--输出日志的格式-->
<PatternLayout pattern="[%d{HH:mm:ss:SSS}] [%p] - %l - %m%n"/>
</MyLog4j2>
</appenders>
<!--然后定义logger，只有定义了logger并引入的appender，appender才会生效-->
<loggers>
<!--过滤掉spring和mybatis的一些无用的DEBUG信息-->
<logger name="org.springframework" level="INFO"></logger>
<logger name="org.mybatis" level="INFO"></logger>
<!-- 自定义包下设置为INFO,则可以看见输出的日志不包含debug输出了 -->
<logger name="cn.lqdev.learning" level="INFO"/>
<root level="all">
<appender-ref ref="oKong"/>
</root>
</loggers>
</configuration>

configuration

packages

cn.lqdev.learning

...部分省略...
一枚趔趄的猿(log4j2)：[14:47:43:751] [INFO] - org.apache.juli.logging.DirectJDKLog.log(DirectJDKLog.java:180) - Using a shared selector for servlet write/read
一枚趔趄的猿(log4j2)：[14:47:43:761] [INFO] - org.springframework.boot.context.embedded.tomcat.TomcatEmbeddedServletContainer.start(TomcatEmbeddedServletContainer.java:216) - Tomcat started on port(s): 8080 (http)
一枚趔趄的猿(log4j2)：[14:47:43:764] [INFO] - org.springframework.boot.StartupInfoLogger.logStarted(StartupInfoLogger.java:57) - Started Chapter25Application in 2.03 seconds (JVM running for 3.164)
一枚趔趄的猿(log4j2)：[14:47:43:764] [INFO] - cn.lqdev.learning.springboot.chapter25.Chapter25Application.main(Chapter25Application.java:14) - Chapter25启动!

log4j2

logback自定义Appender

logback

appender

logback

AppenderBase

UnsynchronizedAppenderBase

appender

MyLogbackAppender.java

@Getter
@Setter
public class MyLogbackAppender extends UnsynchronizedAppenderBase<ILoggingEvent>{

Layout<ILoggingEvent> layout;

//自定义配置
String printString;

@Override
public void start(){
//这里可以做些初始化判断 比如layout不能为null ,
if(layout == null) {
addWarn("Layout was not defined");
}
//或者写入数据库 或者redis时 初始化连接等等
super.start();
}

@Override
public void stop()
{
//释放相关资源，如数据库连接，redis线程池等等
System.out.println("logback-stop方法被调用");
if(!isStarted()) {
return;
}
super.stop();
}

@Override
public void append(ILoggingEvent event) {
if (event == null || !isStarted()){
return;
}
// 此处自定义实现输出
// 获取输出值：event.getFormattedMessage()
// System.out.print(event.getFormattedMessage());
// 格式化输出
System.out.print(printString + "：" + layout.doLayout(event));

}
}

start

stop

logback-spring.xml

<?xml version="1.0" encoding="UTF-8"?>
<configuration debug="false">
<!--定义日志文件的存储地址 勿在 LogBack 的配置中使用相对路径 -->
<property name="LOG_HOME" value="/home" />
<!-- 控制台输出 -->
<appender name="MyLogback"
class="cn.lqdev.learning.springboot.chapter25.config.MyLogbackAppender">
<filter class="ch.qos.logback.classic.filter.ThresholdFilter">
<!-- 日志收集最低日志级别 -->
<level>INFO</level>
</filter>
<layout
class="ch.qos.logback.classic.PatternLayout">
<!--格式化输出：%d表示日期，%thread表示线程名，%-5level：级别从左显示5个字符宽度%msg：日志消息，%n是换行符 -->
<pattern>%d{yyyy-MM-dd HH:mm:ss.SSS} [%thread] %-5level %logger{50} - %msg%n</pattern>
</layout>
<!-- 自定义参数 -->
<printString>一枚趔趄的猿(logback)</printString>
</appender>

<!-- 自定义包下设置为INFO,则可以看见输出的日志不包含debug输出了 -->
<logger name="cn.lqdev.learning" level="INFO" />

<!-- 日志输出级别 -->
<root level="INFO">
<appender-ref ref="MyLogback" />
</root>

</configuration>

...部分省略...
一枚趔趄的猿(logback)：2018-08-25 15:01:57.486 [main] INFO  org.apache.coyote.http11.Http11NioProtocol - Starting ProtocolHandler ["http-nio-8080"]
一枚趔趄的猿(logback)：2018-08-25 15:01:57.497 [main] INFO  org.apache.tomcat.util.net.NioSelectorPool - Using a shared selector for servlet write/read
一枚趔趄的猿(logback)：2018-08-25 15:01:57.520 [main] INFO  o.s.b.c.e.tomcat.TomcatEmbeddedServletContainer - Tomcat started on port(s): 8080 (http)
一枚趔趄的猿(logback)：2018-08-25 15:01:57.523 [main] INFO  c.l.l.springboot.chapter25.Chapter25Application - Started Chapter25Application in 54.349 seconds (JVM running for 55.377)
一枚趔趄的猿(logback)：2018-08-25 15:01:57.524 [main] INFO  c.l.l.springboot.chapter25.Chapter25Application - Chapter25启动!

关于ShutdownHook

appender

stop

ShutdownHook

jvm

一点知识

java

Runtime

Runtime.getRuntime().addShutdownHook(new Thread(new Runnable() {

@Override
public void run() {
// 执行资源释放操作

}
}));

SpringBoot

logging.register-shutdown-hook

true

logging.register-shutdown-hook=true

logback

logback-spring.xml

<shutdownHook class="ch.qos.logback.core.hook.DelayingShutdownHook"/>

DelayingShutdownHook

log4j2

log4j2

start()

stop

参考资料

总结

log4j2

logback

appender

log4j2

logback

最后

SpringBoot

老生常谈

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