log4j示例

log4j.properties
# Set root logger level to ERROR and its only appender to A1. 
log4j.rootLogger=info,testfile,testconsole
# R is set to be a DailyRollingFileAppender. 
log4j.appender.testfile=org.apache.log4j.DailyRollingFileAppender 
log4j.appender.testfile.File=../logs/assinter.log
log4j.appender.testfile.DatePattern = '.'yyyy-MM-dd
log4j.appender.testfile.layout=org.apache.log4j.PatternLayout 
log4j.appender.testfile.layout.ConversionPattern=%p: %d{yyyy-MM-dd HH:mm:ss,SSS}[%t][%l]- %m%nlog4j.appender.testconsole=org.apache.log4j.ConsoleAppender
log4j.appender.testconsole.layout=org.apache.log4j.PatternLayout 
log4j.appender.testconsole.layout.ConversionPattern=%p: %d{yyyy-MM-dd HH:mm:ss,SSS}[%t][%l]- %m%n使用示例:
public class TestDao{
   private static Log log = LogFactory.getLog(TestDao.class);
  public void gotest() {
  try {
   ........
   }catch(Exception e){
    log.error(e.getMessage(), e);
    }
} 
}