log4j的分层打印

深藏阁楼爱情的钟 2022-08-27 10:39 208阅读 0赞

在开发的过程中，我们总会想看到更多的错误，这时候log4j便产生了作用，但是有时候我们总会把日志给打印在一个文件中，那我们如何对各个不同的模块的日志进行分不同的日志文件存放呢，比如dao、service、controller、error、jsp等不同层次的日志。

1、log4j的配置

<?xml version="1.0" encoding="UTF-8" ?>
    <!DOCTYPE log4j:configuration SYSTEM "log4j.dtd">
    <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/">
    
    
    	<appender name="ConsoleAppender" class="org.apache.log4j.ConsoleAppender">
    		<layout class="org.apache.log4j.SimpleLayout" />
    	</appender>
    	
    	<root>
    		<level value="INFO" />
    		<appender-ref ref="ConsoleAppender" />
    	</root>
    	
    	
    	
    	<appender name="dao" class="org.apache.log4j.FileAppender">
    		<param name="File" value="${webapp.root}/logs/dao.log" />
    		<param name="Append" value="true" />
    		
    		<layout class="org.apache.log4j.PatternLayout">
    			<param name="ConversionPattern" value="%d [%t] %p - %m%n" />
    		</layout>
    	</appender>
    	
    	<logger name="com.hj.dao" additivity="true">
    		<level value="INFO" />
    		<appender-ref ref="dao" />
    	</logger>
    	
    	
    	<appender name="service" class="org.apache.log4j.FileAppender">
    		<param name="File" value="${webapp.root}/logs/service.log" />
    		<param name="MaxFileSize" value="5MB" />
    		<param name="MaxBackupIndex" value="20" />
    		<param name="Encoding" value="utf-8"/>
    		<layout class="org.apache.log4j.PatternLayout">
    			<param name="ConversionPattern" value="%d [%-5p][%t] %c{1} %m %n" />
    		</layout>
    	</appender>
    	
    	<logger name="com.hj.service" additivity="true">
    		<level value="INFO" />
    		<appender-ref ref="service" />
    	</logger>
    	
    	
    	<appender name="controller" class="org.apache.log4j.RollingFileAppender">
    		<param name="File" value="${webapp.root}/logs/controller.log" />
    		<param name="MaxFileSize" value="5MB" />
    		<param name="MaxBackupIndex" value="20" />
    		<param name="Encoding" value="utf-8"/>
    		<layout class="org.apache.log4j.PatternLayout">
    			<param name="ConversionPattern" value="%d [%-5p][%t] %c{1} %m %n" />
    		</layout>
    	</appender>
    	
    	
    	<logger name="com.hj.controller" additivity="true">
    		<level value="INFO" />
    		<appender-ref ref="controller" />
    	</logger>
    	
    	
    	<appender name="error" class="org.apache.log4j.RollingFileAppender">
    		<param name="File" value="${webapp.root}/logs/error.log" />
    		<param name="MaxFileSize" value="5MB" />
    		<param name="MaxBackupIndex" value="20" />
    		<param name="Encoding" value="utf-8"/>
    		<layout class="org.apache.log4j.PatternLayout">
    			<param name="ConversionPattern" value="%d [%-5p][%t] %c{1} %m %n" />
    		</layout>
    	</appender>
    	
    	<logger name="com.hj.exception.ErrorHandler" additivity="true">
    		<level value="ERROR" />
    		<appender-ref ref="error" />
    	</logger>
    </log4j:configuration>

2、dao层

@Repository
    public class UserDao {
    	
    	private Logger logger = Logger.getLogger(this.getClass());
    	
    	public void show(){
    		logger.info("this is DAO add");
    	}
    	
    	public void exception(){
    		String str = null;
    		try{
    			str.charAt(2);
    		}catch(Exception e){
    			logger.error("DAO空指针异常", e);
    		}
    	}
    
    	public void throwsExcep() throws Exception{
    		String str = null;
    		logger.info("dao测试异常");
    		str.charAt(2);
    	}
    }

3、service层

@Service
    public class UserService {
    	
    	private Logger logger = Logger.getLogger(this.getClass());
    	
    	@Resource
    	private UserDao userDao;
    	
    	public void show(){
    		logger.info("ths is Service add");
    		userDao.show();
    	}
    	
    	public void exception(){
    		String str = null;
    		try{
    			str.charAt(2);
    		}catch(Exception e){
    			logger.error("Service空指针异常", e);
    		}
    		userDao.exception();
    	}
    	
    	public void throwsExcep() throws Exception{
    		logger.info("service测试异常");
    		userDao.throwsExcep();
    	}
    }

4、controller层

@Controller
    public class UserController {
    	
    	private Logger logger = Logger.getLogger(this.getClass());
    	
    	@Resource
    	private UserService userService;
    	
    	@RequestMapping(value = "/show")
    	public String show(){
    		logger.info("this is Controller add");
    		userService.show();
    		return "index";
    	}
    	
    	@RequestMapping(value = "/exception")
    	public String exception(){
    		String str = null;
    		try{
    			str.charAt(2);
    		}catch(Exception e){
    			logger.error("Controller空指针异常", e);
    		}
    		userService.exception();
    		return "index";
    	}
    
    	@RequestMapping(value = "/throwsExcep")
    	public String throwsExcep() throws Exception{
    		logger.info("controller测试异常");
    		userService.throwsExcep();
    		return "index";
    	}
    }

5、异常处理中心，捕获所有controller的所有异常

@ControllerAdvice 
    public class ErrorHandler {
    	
    	private Logger logger = Logger.getLogger(this.getClass());
    	
    	@ExceptionHandler(value = Exception.class)
        public @ResponseBody Object errorResponse(Exception e) {
    		logger.error("异常处理中心", e);
    		return e;
    	}
    }

6、生成的日志文件

![SouthEast][]

工程下载地址：http://download.csdn.net/detail/wxwzy738/7409341

[SouthEast]: /images/20220824/959ff554663f49879a49fbd05424ebe8.png