log4j2 入门学习与总结

Dear 丶 2022-07-14 05:47 181阅读 0赞

### 目录 ###

*  [log4j223入门学习与总结][log4j223]
    
     *  [大纲][Link 1]
        
         *  [目录][Link 2]
            
             *  [一log4j2 配置文件加载][log4j2]
             *  [二log4j2 配置文件结构图][log4j2 1]
             *  [三log4j2 配置文件说明][log4j2 2]
             *  [四log4j2 AppenderschildFilterThresholdFilter 的使用][log4j2 AppenderschildFilterThresholdFilter]
             *  [五log4j2 实战示例][log4j2 3]
             *  [六log4j2 logger 加载规则][log4j2 logger]

--------------------

#### 一、log4j2 配置文件加载 ####

log4j2 的配置文件只用 xml、json、jsn 三种格式，默认情况下由系统自动加载，系统加载 classpath 目录如下的配置文件：   
\- log4j-test.json 或者 log4j-test.jsn 文件   
\- log4j2-test.xml   
\- log4j-test.json 或者 log4j-test.jsn 文件   
\- log4j2.xml   
加载优先级由上向下，且只加载其一。

#### 二、log4j2 配置文件结构图 ####

![这里写图片描述][20160620200255928]

#### 三、log4j2 配置文件说明 ####

1、configration

<table style="width:708px; border-collapse:collapse; border-spacing:0px; border:1px solid rgb(238,238,238); color:rgb(51,51,51); font-family:&quot;microsoft yahei&quot;; font-size:14px"> 
 <thead style=""> 
  <tr style=""> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 字段</th> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 描述</th> 
  </tr> 
 </thead> 
 <tbody style=""> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> status</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 日志级别 默认值为最高级别 OFF</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> monitorInterval</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 监控间隔，例如：monitorInterval=”600” 指log4j2每隔600秒（10分钟），自动监控该配置文件是否有变化，如果变化，则自动根据文件内容重新配置</td> 
  </tr> 
 </tbody> 
</table>

2、Appenders 定义输出类型   
1) Child

<table style="width:708px; border-collapse:collapse; border-spacing:0px; border:1px solid rgb(238,238,238); color:rgb(51,51,51); font-family:&quot;microsoft yahei&quot;; font-size:14px"> 
 <thead style=""> 
  <tr style=""> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 字段</th> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 描述</th> 
  </tr> 
 </thead> 
 <tbody style=""> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> Layout</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 输出类型的模板、布局</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> Filters</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 过滤器，过滤掉不需要的日志</td> 
  </tr> 
 </tbody> 
</table>

2)Filters.ThresholdFilter

<table style="width:708px; border-collapse:collapse; border-spacing:0px; border:1px solid rgb(238,238,238); color:rgb(51,51,51); font-family:&quot;microsoft yahei&quot;; font-size:14px"> 
 <thead style=""> 
  <tr style=""> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 字段</th> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 描述</th> 
  </tr> 
 </thead> 
 <tbody style=""> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> level</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 输出级别，例：level=”info”,日志级别为info或者以上(匹配的界别)</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> onMatch</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> DENY/ACCEPT 禁止或者接受（是否接受匹配）</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> onMismatch</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> DENY/NEUTRAL （是否接受其他高于level的级别）</td> 
  </tr> 
 </tbody> 
</table>

一般的组合为：

*  onMatch=”DENY” onMismatch=”NEUTRAL “
 *  onMatch=”ACCEPT ” onMismatch=”DENY”

3、Loggers 注册日志输出对象   
1) Logger 日志输出对象

<table style="width:708px; border-collapse:collapse; border-spacing:0px; border:1px solid rgb(238,238,238); color:rgb(51,51,51); font-family:&quot;microsoft yahei&quot;; font-size:14px"> 
 <thead style=""> 
  <tr style=""> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 字段</th> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 解释</th> 
  </tr> 
 </thead> 
 <tbody style=""> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> name</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 输出对象名称</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> level</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 日志级别</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> additivity</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 是否冒泡，既在本层输出日志后是否需要在父对象上输出该日志，默认为 true</td> 
  </tr> 
 </tbody> 
</table>

代码说明

<Root level="info">
        <AppenderRef ref="Appender3" />
    </Root>
    
    <logger level="warn" name="com.person" additivity="false">
       <AppenderRef ref="Appender1" />
    </logger>
    
    <logger level="info" name="com.person.man" additivity="true">
        <AppenderRef ref="Appender2" />
    </logger>
     
      
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在 com.person.man 包下面或者类下面执行以下代码

logger.info("man info");    // Appender1、Appender2 有输出
    logger.error("man error");  // Appender1、Appender2 有输出
    logger.warn("man warn");    // Appender1、Appender2 有输出
     
      
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#### 四、log4j2 Appenders.child.Filter.ThresholdFilter 的使用 ####

#### 五、log4j2 实战示例 ####

1、根据日志级别输出到不同文件，按日期进行封存日志

<?xml version="1.0" encoding="UTF-8"?>
    
    
    <configuration status="off" monitorInterval="600"> 
      <properties>
        <property name="LOG_HOME">E:/webbase/logs</property>
        <property name="LOG_BACK_HOME">${LOG_HOME}/backup</property>
        <property name="ERROR_FILE_NAME">error</property>
        <property name="WARN_FILE_NAME">warn</property>
        <property name="INFO_FILE_NAME">info</property>
        <property name="DEBUG_FILE_NAME">debug</property>
      </properties>
      <Appenders>
        <Console name="Console" target="SYSTEM_OUT">
          <PatternLayout pattern="%d{HH:mm:ss.SSS} {%t} %-5level %logger{36} - %msg%n"/>
        </Console>
            
        
        <RollingFile name="ErrLog" fileName="${LOG_HOME}/${ERROR_FILE_NAME}.log" filePattern="${LOG_BACK_HOME}/$${date:yyyy-MM}/${ERROR_FILE_NAME}.%d{yyyy-MM-dd}.log" append="true">  
                
            <PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n"/>  
              
            <Policies>    
                  
                <TimeBasedTriggeringPolicy interval="1" modulate="true" />   
            </Policies> 
            <Filters>
             <ThresholdFilter level="error" onMatch="ACCEPT" onMismatch="DENY"/>
            </Filters>
        </RollingFile> 
    
        
        <RollingFile name="WarnLog" fileName="${LOG_HOME}/${WARN_FILE_NAME}.log" filePattern="${LOG_BACK_HOME}/$${date:yyyy-MM}/${WARN_FILE_NAME}.%d{yyyy-MM-dd}.log" append="true">  
                
            <PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n"/>  
              
            <Policies>    
                <TimeBasedTriggeringPolicy interval="1" modulate="true" />   
            </Policies> 
            <Filters>
              <ThresholdFilter level="error" onMatch="DENY" onMismatch="NEUTRAL"/>
              <ThresholdFilter level="warn" onMatch="ACCEPT" onMismatch="DENY"/>
            </Filters>
        </RollingFile> 
        
        <RollingFile name="InfoLog" fileName="${LOG_HOME}/${INFO_FILE_NAME}.log" filePattern="${LOG_BACK_HOME}/$${date:yyyy-MM}/${INFO_FILE_NAME}.%d{yyyy-MM-dd}.log" append="true">  
                
            <PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n"/>  
              
            <Policies>    
                <TimeBasedTriggeringPolicy interval="1" modulate="true" />   
            </Policies> 
            <Filters>
              <ThresholdFilter level="warn" onMatch="DENY" onMismatch="NEUTRAL"/>
              <ThresholdFilter level="info" onMatch="ACCEPT" onMismatch="DENY"/>
            </Filters>
        </RollingFile> 
        
        <RollingFile name="DebugLog" fileName="${LOG_HOME}/${DEBUG_FILE_NAME}.log" filePattern="${LOG_BACK_HOME}/$${date:yyyy-MM}/${DEBUG_FILE_NAME}.%d{yyyy-MM-dd}.log" append="true">  
                
            <PatternLayout pattern="%date{yyyy-MM-dd HH:mm:ss.SSS} %level [%thread][%file:%line] - %msg%n"/>  
              
            <Policies>    
                <TimeBasedTriggeringPolicy interval="1" modulate="true" />   
            </Policies> 
            <Filters>
              <ThresholdFilter level="info" onMatch="DENY" onMismatch="NEUTRAL"/>
              <ThresholdFilter level="debug" onMatch="ACCEPT" onMismatch="DENY"/>
            </Filters>
        </RollingFile> 
      </Appenders>
      <Loggers>
        <Logger name="org.webbase" level="debug" additivity="true">
            <AppenderRef ref="DebugLog" />
            <AppenderRef ref="InfoLog" />
        </Logger>
        <Root level="warn">
            <AppenderRef ref="WarnLog" />
            <AppenderRef ref="ErrLog" />
            <AppenderRef ref="Console"/>
        </Root>
      </Loggers>
    </configuration>
     
      
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TimeBasedTriggeringPolicy

<table style="width:708px; border-collapse:collapse; border-spacing:0px; border:1px solid rgb(238,238,238); color:rgb(51,51,51); font-family:&quot;microsoft yahei&quot;; font-size:14px"> 
 <thead style=""> 
  <tr style=""> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 属性</th> 
   <th style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> 解释</th> 
  </tr> 
 </thead> 
 <tbody style=""> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> interval</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> （integer）该属性是相对 RollingFile.filePattern 中的&nbsp;<br style=""> %d{yyyy-MM-dd}值,例：<br style=""> filePattern=”xxx%d{yyyy-MM-dd}xx” interval=”2” 表示将2天一个日志文件；<br style=""> filePattern=”xxx%d{yyyy-MM-dd-HH}xx” interval=”1”表示一个小时一个日志文件</td> 
  </tr> 
  <tr style=""> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> modulate</td> 
   <td style="padding:8px; line-height:20px; vertical-align:top; border:1px solid rgb(238,238,238)"> （boolean）以0点为边界进行偏移计算</td> 
  </tr> 
 </tbody> 
</table>

#### 六、log4j2 logger 加载规则 ####

1.  logger name 相同时，以 level 级别高的为准
2.  logger name = “org” 会被 name=”org.xxx” 继承
3.  logger 中的 additivity=”true” 表示子日志所获得的日志也会在父日志中出现，即使 父日志的 level 远高于子日志的 level
4.  当子日志 level 大于 父日志时，父日志只能接收到子日志过滤后的日志

[log4j223]: http://blog.csdn.net/u010201484/article/details/51723455#log4j223入门学习与总结
[Link 1]: http://blog.csdn.net/u010201484/article/details/51723455#大纲
[Link 2]: http://blog.csdn.net/u010201484/article/details/51723455#目录
[log4j2]: http://blog.csdn.net/u010201484/article/details/51723455#一log4j2-配置文件加载
[log4j2 1]: http://blog.csdn.net/u010201484/article/details/51723455#二log4j2-配置文件结构图
[log4j2 2]: http://blog.csdn.net/u010201484/article/details/51723455#三log4j2-配置文件说明
[log4j2 AppenderschildFilterThresholdFilter]: http://blog.csdn.net/u010201484/article/details/51723455#四log4j2-appenderschildfilterthresholdfilter-的使用
[log4j2 3]: http://blog.csdn.net/u010201484/article/details/51723455#五log4j2-实战示例
[log4j2 logger]: http://blog.csdn.net/u010201484/article/details/51723455#六log4j2-logger-加载规则
[20160620200255928]: /images/20220714/062c655633e446ffbe175a09e99dde90.png