log4j–动态打印日志文件到指定文件夹
1、添加Maven依赖
<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>
2、配置文件 log4j.properties
log4j.rootLogger = debug,stdout,file
### 输出到控制台 ###
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 = %d{ABSOLUTE} %5p %c{1}:%L - %m%n
### 输出到日志文件 ###
log4j.appender.file = org.apache.log4j.DailyRollingFileAppender
###设置DatePattern,当天日志保存到log.log文件,前一天的日志文件名将被修改为log.log + _yyyy-MM-dd.log
log4j.appender.file.File =D/logs/log.log
log4j.appender.file.DatePattern = '_'yyyy-MM-dd'.log'
log4j.appender.file.Append = true
## 输出DEBUG级别以上的日志
log4j.appender.file.Threshold = DEBUG
log4j.appe