log4j2动态修改日志级别及拓展性使用详解

<?xml version="1.0" encoding="UTF-8"?><!-- 配置LoggerConfig，即Appenders的日志级别为WARN --><Configuration status="WARN">  <!-- 定义下面的引用名 -->  <Properties>    <property name="basePath">${sys:vmparam}</property>    <property name="filePath">${basePath}/app.log</property>  </Properties>  <!-- Appenders支持配置多个Appender，支持向不同的目标输送日志，本例为配置向控制台输出 -->  <Appenders>    <Console name="Console" target="SYSTEM_OUT">      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" />    </Console>    <!-- 将日志输出到指定位置的文件中 -->    <RollingFile name="RollingFile" fileName="${filePath}"      filePattern="logs/$${date:yyyy-MM}/app-%d{yyyy-MM-dd-HH}-%i.log.gz">      <Policies>        <!-- interval单位为filePattern最后一个单位，此处为6小时，modulate若为true，        则日志时间将以0点为边界进行偏移计算，由于加了.gz策略，所以此处意思为每隔6小时，便会新生成一个        log4j2的压缩文件，当每个文件超过250M时，也会新生成一个log4j2的压缩文件 -->        <TimeBasedTriggeringPolicy interval="6" modulate="true"/>        <SizeBasedTriggeringPolicy size="250 MB"/>      </Policies>      <!-- 滚动策略，日志文件最多保留20个 -->      <DefaultRolloverStrategy max="20"/>      <!-- 最多备份30天以内||日志文件大小达到100GB的日志||文件数量超过十个      此处为策略限制，Delete中可以按自己需要用正则表达式编写 -->      <DefaultRolloverStrategy>        <Delete basePath="${filePath}" maxDepth="1">          <IfFileName glob="logs_*.log" />          <IfLastModified age="30d" />          <IfAccumulatedFileSize exceeds="100 GB" />          <IfAccumulatedFileCount exceeds="10" />        </Delete>      </DefaultRolloverStrategy>    </RollingFile>  </Appenders>  <!-- Loggers支持配置多个Logger，可引用不同的目标Appender，也可根据业务需求定制特定要求的Appender -->  <Loggers>        <AsyncLogger name="AsyncLogger" level="trace">      <appender-ref ref="Console" />      <appender-ref ref="RollingFile" />    </AsyncLogger>     <asyncRoot level="trace">      <appender-ref ref="Console" />    </asyncRoot>         <Root level="info">      <!-- <AppenderRef ref="Console" /> -->      <AppenderRef ref="RollingFile" />    </Root>        <!-- 第三方日志系统 -->    <logger name="org.springframework" level="INFO" additivity="false">      <appender-ref ref="Console" />    </logger>    <logger name="io.netty" level="warn"/>    <logger name="org.apache.http" level="warn"/>    <logger name="org.mongodb.driver" level="INFO"/>    <logger name="org.jboss.netty" level="warn"/>    <logger name="org.springframework.data.redis" level="INFO"/>  </Loggers></Configuration>

Collection<org.apache.logging.log4j.core.Logger> current = LoggerContext.getContext(false).getLoggers();Collection<org.apache.logging.log4j.core.Logger> notcurrent = LoggerContext.getContext().getLoggers();Collection<org.apache.logging.log4j.core.Logger> allConfig = current;allConfig.addAll(notcurrent);for (org.apache.logging.log4j.core.Logger log:allConfig){  log.setLevel(Level.DEBUG);}　

package com.jyk.log4j2.log4j2_test;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; @Plugin(name = "MyAppender", category = "Core", elementType = "appender", printObject = true)public class MyAppender 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 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 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            //拿到每次打印的日志，写自己的业务逻辑      System.out.println("enter my append...");    } 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 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);  }}

<Configuration status="WARN" packages="com.jyk.log4j2.log4j2_test"><MyAppender name="textarea">      <PatternLayout pattern="%d{HH:mm:ss.SSS} [%t] %-5level %logger{36} - %msg%n" /></MyAppender>