解决执行MapReduce程序控制台没有日志信息WARN Please initialize the log4j system properly

 运行mapreduce的时候，发现没有日志文件，会提示警告:
 
log4j:WARN No appenders could be found for logger (org.apache.hadoop.metrics2.lib.MutableMetricsFactory).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

 发现控制台重来没有输出过mapreduce的任务信息情况。后来发现需要配置log4j。
 在resource目录下创建一个log4j.properties文件

 添加如下信息:

log4j.rootLogger=info, stdout  
log4j.appender.stdout=org.apache.log4j.ConsoleAppender  
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout  
log4j.appender.stdout.layout.ConversionPattern=%d %p [%c] - %m%n  

log4j.appender.File=org.apache.log4j.DailyRollingFileAppender
log4j.appender.File.File=D:/test/logs.txt
log4j.appender.File.DatePattern='_'yyyy-MM-dd'.txt'
log4j.appender.File.layout=org.apache.log4j.PatternLayout
log4j.appender.File.layout.ConversionPattern=%d %t %-5p [%c] %m%n