how to use the log4j for the standalone app

[lihu]

Hi,
   I use the spark0.9, and when i run the spark-shell, I can log property
according the log4j.properties in the SPARK_HOME/conf directory.But when I
use the standalone app, I do not know how to log it.

  I use the SparkConf to set it, such as:

  *val conf = new SparkConf()*
*  conf.set("*log4j.configuration*", "/home/hadoop/spark/conf/l*
*og4j.properties**")*

  but it does not work.

  this question maybe simple, but I can not find anything in the web. and I
think this maybe helpful for many people who do not familiar with spark.