1，关于日志记录是开发中必不可少的知识，现在给大家详细说下如何记录日志信息；原理就不多说了看实际操作

2，配置log4j文件：具体配置表示什么意思就不说了一看就明白 嘿嘿

log4j.rootCategory=DEBUG,stdlog,errorlog

log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.Threshold=ERROR log4j.appender.stdlog.File=d:/error.log log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d{yyyy/MM/dd HH:mm:ss} [%c{1}] - %m%n log4j.appender.stdlog=org.apache.log4j.RollingFileAppender log4j.appender.stdlog.Threshold=DEBUG,console log4j.appender.stdlog.File=d:/debug.log log4j.appender.stdlog.MaxFileSize=1024KB log4j.appender.stdlog.MaxBackupIndex=3 log4j.appender.stdlog.layout=org.apache.log4j.PatternLayout log4j.appender.stdlog.layout.ConversionPattern=%d{yyyy/MM/dd HH:mm:ss} %-5p [%c{1}] - %m%n log4j.appender.errorlog=org.apache.log4j.RollingFileAppender log4j.appender.errorlog.Threshold=WARN log4j.appender.errorlog.File=d:/warn.log log4j.appender.errorlog.MaxFileSize=1024KB log4j.appender.errorlog.MaxBackupIndex=3 log4j.appender.errorlog.layout=org.apache.log4j.PatternLayout log4j.appender.errorlog.layout.ConversionPattern=%d [%c{1}] - %m%n

3，具体代码:

Log4JLogger l = new Log4JLogger("log4j.properties"); //初始化日志驱动

l.logDebug("--->dug记录");l.logError("日志正在记录...");l.logInfo("消息记录中...");try { Log4JLogger ll = null;ll.logDebug("---");} catch (Exception e) { l.logDebug(e, e.fillInStackTrace());       l.logError(e,e.fillInStackTrace());}

4，保存的日志信息:

2013/01/24 16:51:03 ERROR [properties] - 日志正在记录...

2013/01/24 16:51:03 INFO  [properties] - 消息记录中... 2013/01/24 16:51:03 DEBUG [properties] - java.lang.NullPointerException java.lang.NullPointerExceptionat ddm.DataDriverManager.showSysInfo(DataDriverManager.java:47)at ddm.DataDriverManager.main(DataDriverManager.java:20) 2013/01/24 16:51:03 ERROR [properties] - java.lang.NullPointerException java.lang.NullPointerExceptionat ddm.DataDriverManager.showSysInfo(DataDriverManager.java:48)at ddm.DataDriverManager.main(DataDriverManager.java:20)

5,大功高成！ 觉得可以的哥们儿希望给个好评！

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