SpringBoot如何配置log4j输出日志呢？

转自:

SpringBoot如何配置log4j输出日志呢？

下文笔者讲述SpringBoot配置log4j的方法分享,如下所示

SpringBoot日志输出

springboot框架中默认使用logback进行日志输出
当然它也可以配置其它的日志框架

SpringBoot配置log4j

Springboot配置log4j的方法:
   1.添加log4j.properties配置文件
   2.初始化配置文件

配置log4j文件

 添加log4j.properties配置文件
 配置文件添加的路径
   在工程src/main/resources下

文件内容

#log4j.rootLogger=CONSOLE,info,error,DEBUG
log4j.rootLogger=info,error,CONSOLE,DEBUG

log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender     
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout     
log4j.appender.CONSOLE.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n     
      
log4j.logger.info=info
log4j.appender.info=org.apache.log4j.DailyRollingFileAppender
log4j.appender.info.layout=org.apache.log4j.PatternLayout     
log4j.appender.info.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n  
log4j.appender.info.datePattern='.'yyyy-MM-dd
log4j.appender.info.Threshold = info   
log4j.appender.info.append=true   
#log4j.appender.info.File=/home/java265project/logs/info/api_services_info
log4j.appender.info.File=/Users/java265project/logs/info/api_services_info

log4j.logger.error=error  
log4j.appender.error=org.apache.log4j.DailyRollingFileAppender
log4j.appender.error.layout=org.apache.log4j.PatternLayout     
log4j.appender.error.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n  
log4j.appender.error.datePattern='.'yyyy-MM-dd
log4j.appender.error.Threshold = error   
log4j.appender.error.append=true   
#log4j.appender.error.File=/home/java265project/logs/error/api_services_error
log4j.appender.error.File=/Users/java265project/logs/error/api_services_error

log4j.logger.DEBUG=DEBUG
log4j.appender.DEBUG=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DEBUG.layout=org.apache.log4j.PatternLayout     
log4j.appender.DEBUG.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n  
log4j.appender.DEBUG.datePattern='.'yyyy-MM-dd
log4j.appender.DEBUG.Threshold = DEBUG   
log4j.appender.DEBUG.append=true   
#log4j.appender.DEBUG.File=/home/java265project/logs/debug/api_services_debug
log4j.appender.DEBUG.File=/Users/java265project/logs/debug/api_services_debug

### Debug
log4j.logger.com.ibatis=DEBUG
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=DEBUG
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=DEBUG
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=DEBUG
log4j.logger.java.sql.Connection=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

注意事项:
    1.log4j.properties文件中
      当部署线上环境，需要释放掉注释语句，并注释线下配置语句。
      #log4j.appender.info.File=/home/java265project/logs/info/api_services_info
     log4j.appender.info.File=/Users/java265project/logs/info/api_services_info
    2.日志配置涉及三个级别:info、error、debug

例:

初始化log4j配置

springboot启动是通过main入口函数
需在main入口函数中设置log4j初始化

public class App {
	
	private static final Logger logger = LoggerFactory.getLogger(App.class);	
	
	@Value("${server.port}")
	private int port;
	@Value("${server.sessionTimeout}")
	private int sessionTimeout;
	
	static {
		try{
		   // 初始化log4j
		   String log4jPath = "";
		   if(Constant.LOG_MODE == 1){
			   // 配置线上地址
			   log4jPath = App.class.getClassLoader().getResource("").getPath()+"java265project/config/log4j.properties";
			   logger.info("Log4j线上生产模式初始化。。。");	
		   }else{
			   // 配置本地地址
			   log4jPath = App.class.getClassLoader().getResource("").getPath()+"log4j.properties";
			   logger.info("Log4j线下开发模式初始化。。。");	
		   }		   		   
		   logger.info("初始化Log4j。。。。");	
		   logger.info("path is "+ log4jPath);	
		   PropertyConfigurator.configure(log4jPath);
		}catch (Exception e){			  
			  logger.error(e.toString());	
		}
    }

	public static void main(String[] args) {
		
		final String[] temp = args;
		
		logger.info("oops: main入口函数编码-" +System.getProperty("file.encoding"));
		
		if(Constant.LOG_MODE == 0){
			SpringApplication.run(App.class, args);
			logger.info("oops: 线下开发测试");		
		}else{
			logger.info("oops:" + args[0]);		
		}
							
		if(ArrayUtils.isNotEmpty(args))
	    {
	        // 如果你的应用程序，运行后不自动退出，那么处理start时不要执行正常的代码，否则在部署测试 appctl.sh 的时候，会一直等待进程退出
	        if(args[0].equals("startup"))
	        {	            	            
	        	new Thread(
	        		new Runnable(){
	        			public void run(){
	        				System.out.println("启动Mythread子线程");
	        				logger.info("启动Mythread子线程");	
	        				SpringApplication.run(App.class, temp);		        	        
	        			}
	        	}).start();
	        	
	        	System.out.println("program startup");
	    		logger.info("program startup");		    		
	        }else if(args[0].equals("stop"))
	        {
	            System.out.println("program stop");
	            logger.info("program stop");		            
	        }else if(args[0].equals("restart"))
	        {
	            System.out.println("program restart");
	            logger.info("program restart");	
	        }else if(args[0].equals("status"))
	        {
	            System.out.println("program status");
	            logger.info("program status");	
	        }
	    }		 
	}

优化配置

可对log4j.properties文件进行调整
使其配置更简单

log4j.rootLogger=${log.root}

log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender
log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout
log4j.appender.CONSOLE.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n
      
log4j.logger.info=info
log4j.appender.info=org.apache.log4j.DailyRollingFileAppender
log4j.appender.info.layout=org.apache.log4j.PatternLayout
log4j.appender.info.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n
log4j.appender.info.datePattern='.'yyyy-MM-dd
log4j.appender.info.Threshold = info
log4j.appender.info.append=true
log4j.appender.info.File=${log.base}/java265project/logs/info/api_services_info

log4j.logger.error=error
log4j.appender.error=org.apache.log4j.DailyRollingFileAppender
log4j.appender.error.layout=org.apache.log4j.PatternLayout
log4j.appender.error.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n
log4j.appender.error.datePattern='.'yyyy-MM-dd
log4j.appender.error.Threshold = error
log4j.appender.error.append=true
log4j.appender.error.File=${log.base}/java265project/logs/error/api_services_error

log4j.logger.DEBUG=DEBUG
log4j.appender.DEBUG=org.apache.log4j.DailyRollingFileAppender
log4j.appender.DEBUG.layout=org.apache.log4j.PatternLayout
log4j.appender.DEBUG.layout.ConversionPattern=%d{yyyy-MM-dd-HH-mm} [%t] [%c] [%p] - %m%n
log4j.appender.DEBUG.datePattern='.'yyyy-MM-dd
log4j.appender.DEBUG.Threshold = DEBUG
log4j.appender.DEBUG.append=true
log4j.appender.DEBUG.File=${log.base}/java265project/logs/debug/api_services_debug

### Debug
log4j.logger.com.ibatis=DEBUG
log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=DEBUG
log4j.logger.com.ibatis.common.jdbc.ScriptRunner=DEBUG
log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientDelegate=DEBUG
log4j.logger.java.sql.Connection=DEBUG
log4j.logger.java.sql.Statement=DEBUG
log4j.logger.java.sql.PreparedStatement=DEBUG

与之相应的main函数新增如下代码，同时去掉static代码块：

System.setProperty("log.root",Constant.LOG_ROOT_DAILY);			
System.setProperty("log.base",Constant.LOG_PATH_DAILY);