自带日志

  1. public class Hello {
  2.     public static void main(String[] args) {
  3.         Logger logger = Logger.getGlobal();
  4.         logger.info("start process...");
  5.         logger.warning("memory is running out...");
  6.         logger.fine("ignored.");
  7.         logger.severe("process will be terminated...");
  8.     }
  9. }

Log4j

resources目录下创建log4j.properties文件

  1.  ### 设置###
  2. log4j.rootLogger = debug,stdout,D,E
  3. ### 输出信息到控制抬 ###
  4. log4j.appender.stdout = org.apache.log4j.ConsoleAppender
  5. log4j.appender.stdout.Target = System.out
  6. log4j.appender.stdout.layout = org.apache.log4j.PatternLayout
  7. log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n
  9. ### 输出DEBUG 级别以上的日志到=/home/duqi/logs/debug.log ###
  10. log4j.appender.D = org.apache.log4j.DailyRollingFileAppender
  11. log4j.appender.D.File = C:debug.log
  12. log4j.appender.D.Append = true
  13. log4j.appender.D.Threshold = DEBUG 
  14. log4j.appender.D.layout = org.apache.log4j.PatternLayout
  15. log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n
  17. ### 输出ERROR 级别以上的日志到=/home/admin/logs/error.log ###
  18. log4j.appender.E = org.apache.log4j.DailyRollingFileAppender
  19. log4j.appender.E.File =C:error.log 
  20. log4j.appender.E.Append = true
  21. log4j.appender.E.Threshold = ERROR 
  22. log4j.appender.E.layout = org.apache.log4j.PatternLayout
  23. log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss}  [ %t:%r ] - [ %p ]  %m%n

输出日志的例子

  1. package com.javadu.log;
  3. import org.slf4j.Logger;
  4. import org.slf4j.LoggerFactory;
  6. public class Log4JTest {
  7.     private static final Logger logger = LoggerFactory.getLogger(Log4JTest.class);
  9.     public static void main(String[] args) {
  10.         // 记录debug级别的信息
  11.         logger.debug("This is debug message.");
  12.         // 记录info级别的信息
  13.         logger.info("This is info message.");
  14.         // 记录error级别的信息
  15.         logger.error("This is error message.");
  16.     }
  17. }