log4j2输出Logger到控制台

淩亂°似流年 2022-05-21 04:28 352阅读 0赞

在log4j1的时候用这种获取  protected Logger logger = LoggerFactory.getLogger(getClass());

log4j2的时候用这种获取    protected Logger logger = LogManager.getLogger(UserController.class);

区别看红色部分。

注意导入的包是这两个

import org.apache.logging.log4j.LogManager;
    import org.apache.logging.log4j.Logger;

升级到log4j2后，需要用第二张方式。

可以在代码中写上代码试试能否输出日志

logger.trace("=====trace=====");  
            logger.debug("=====debug=====");  
            logger.info("=====info=====");  
            logger.warn("=====warn=====");  
            logger.error("=====error=====");

下面把log4j2的具体配置步骤都记录一下：

pom.xml  用到的jar包

<dependency>
    			<groupId>org.slf4j</groupId>
    			<artifactId>slf4j-api</artifactId>
    			<version>1.7.21</version>
    		</dependency>
    		<dependency>
    			<groupId>org.slf4j</groupId>
    			<artifactId>slf4j-log4j12</artifactId>
    			<version>1.7.21</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.apache.logging.log4j</groupId>
    			<artifactId>log4j-api</artifactId>
    			<version>2.8.2</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.apache.logging.log4j</groupId>
    			<artifactId>log4j-core</artifactId>
    			<version>2.8.2</version>
    		</dependency>
    		
    		<dependency>
    			<groupId>org.apache.logging.log4j</groupId>
    			<artifactId>log4j-web</artifactId>
    			<version>2.8.2</version>
    		</dependency>

web.xml

<context-param>
    		<param-name>log4jConfiguration</param-name>
    		<param-value>classpath:config/log4j2.xml</param-value>
    	</context-param>
    	<listener>
    		<listener-class>org.apache.logging.log4j.web.Log4jServletContextListener</listener-class>
    	</listener>
    	<filter>
    		<filter-name>log4jServletFilter</filter-name>
    		<filter-class>org.apache.logging.log4j.web.Log4jServletFilter</filter-class>
    	</filter>
    	<filter-mapping>
    		<filter-name>log4jServletFilter</filter-name>
    		<url-pattern>/*</url-pattern>
    		<dispatcher>REQUEST</dispatcher>
    		<dispatcher>FORWARD</dispatcher>
    		<dispatcher>INCLUDE</dispatcher>
    		<dispatcher>ERROR</dispatcher>
    	</filter-mapping>

log4j2.xml配置文件

<?xml version="1.0" encoding="UTF-8"?>  
      <Configuration status="OFF" monitorInterval="1800">
        
          <properties>  
          	
              <property name="LOG_HOME">C:/Users/lenovo/Desktop/logs/</property>
              <property name="ERROR_LOG_FILE_NAME">error</property>
          </properties>  
          <Appenders>  
          	
              <Console name="Console" target="SYSTEM_OUT">  
                  <PatternLayout pattern="%d %-5p (%F:%L) - %m%n" />  
              </Console>  
        	
              <RollingRandomAccessFile name="ErrorLog"  
                                       fileName="${LOG_HOME}/${ERROR_LOG_FILE_NAME}.log"  
                                       filePattern="${LOG_HOME}/${ERROR_LOG_FILE_NAME}.log.%d{yyyy-MM-dd}.gz">  
                  <PatternLayout  
                          pattern="%d %-5p (%F:%L) - %m%n"/>  
                  <Policies>  
                  	  
                      <TimeBasedTriggeringPolicy/>  
                      
                      <SizeBasedTriggeringPolicy size="100 MB"/>  
                  </Policies>
                    
                  <DefaultRolloverStrategy max="20"/>  
              </RollingRandomAccessFile>  
              <param name="Encoding" value="UTF-8" />
          </Appenders>  
        
          <Loggers>  
                
              <logger name="org.springframework.core" level="info">  
              </logger>  
              <logger name="org.springframework.beans" level="info">  
              </logger>  
              <logger name="org.springframework.context" level="info">  
              </logger>  
              <logger name="org.springframework.web" level="info">  
              </logger>  
              <logger name="org.springframework.test.context.junit4.SpringJUnit4ClassRunner" level="info">  
              </logger>  
              
              <logger name="com.fast.ssm" level="debug" includeLocation="true" additivity="false">
                  <appender-ref ref="ErrorLog"/>  
                  <appender-ref ref="Console"/>  
              </logger>  
              <root level="info" includeLocation="true">
                  <appender-ref ref="ErrorLog"/>
                  <appender-ref ref="Console"/>  
              </root>  
          </Loggers>  
      </Configuration>

spring-mybatis的配置文件（SqlMapConfig.xml）注意：<settings>标签顺序，要在最上面

SqlCostInterceptor   sql语句拦截器

/**
     * Sql执行时间记录拦截器 
     */
    @Intercepts({@Signature(type = StatementHandler.class, method = "query", args = {Statement.class, ResultHandler.class}),
     @Signature(type = StatementHandler.class, method = "update", args = {Statement.class}),
     @Signature(type = StatementHandler.class, method = "batch", args = { Statement.class })})
    public class SqlCostInterceptor implements Interceptor {
     
     @Override
     public Object intercept(Invocation invocation) throws Throwable {
       
      long startTime = System.currentTimeMillis();
      try {
       return invocation.proceed();
      } finally {
       long endTime = System.currentTimeMillis();
       long sqlCost = endTime - startTime;
       System.out.println("执行耗时 : [" + sqlCost + "ms ] ");
      }
     }
     
     @Override
     public Object plugin(Object target) {
      return Plugin.wrap(target, this);
     }
     
     @Override
     public void setProperties(Properties properties) {
       
     }
      
    }

配置文件就这些，注意有的路径需要改一下。