MyBatis中日志工厂与log4j

1.日志工厂

如果一个数据库出现了异常，需要排错，日志就是最好的助手

在mybatis-config.xml中配置：

2.log4j

1.先导入Log4j的包
2.log4j.properties:

### 设置###
log4j.rootLogger = debug,stdout,D,E

### 输出信息到控制抬 ###
log4j.appender.stdout = org.apache.log4j.ConsoleAppender
log4j.appender.stdout.Target = System.out
log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n

### 输出DEBUG 级别以上的日志到=E://logs/error.log ###
log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
log4j.appender.D.File = E://logs/log.log
log4j.appender.D.Append = true
log4j.appender.D.Threshold = DEBUG 
log4j.appender.D.layout = org.apache.log4j.PatternLayout
log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

### 输出ERROR 级别以上的日志到=E://logs/error.log ###
log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
log4j.appender.E.File =E://logs/error.log 
log4j.appender.E.Append = true
log4j.appender.E.Threshold = ERROR 
log4j.appender.E.layout = org.apache.log4j.PatternLayout
log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

3.配置log4j为日志的实现：

<settings>
   <setting name="logImpl" value="LOG4J"/>
</settings>

4.简单使用

package com.kuang.dao;
import org.apache.log4j.Logger;
import org.junit.Test;
public class UserDaoTest {
    static Logger logger =  Logger.getLogger(UserDaoTest.class);
    @Test
    public void testLog4j(){
        logger.info("info进入了testLog4j");
        logger.debug("debug:进入了testLog4j");
        logger.error("error:进入了Log4j");
    }
}