1.在工程中导入log4j的jar包。
2.在src目录下新建log4j.properties文件
3.log4j.properties中输入
log4j.rootLogger=INFO, stdout, file
log4j.appender.stdout.Target=System.out
log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=%n%-d{yyyy-MM-dd HH:mm:ss}%n[%p]-[Thread: %t]-[%C.%M()]: %m%n
# Output to the File
log4j.appender.file=org.apache.log4j.FileAppender
log4j.appender.file.File=./myapp.log
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%n%-d{yyyy-MM-dd HH:mm:ss}%n[%p]-[Thread: %t]-[%C.%M()]: %m%n
# Druid
log4j.logger.druid.sql=warn,stdout
log4j.logger.druid.sql.DataSource=warn,stdout
log4j.logger.druid.sql.Connection=warn,stdout
log4j.logger.druid.sql.Statement=debug,stdout
log4j.logger.druid.sql.ResultSet=warn,stdout