我們在使用Log4j的時候，總是出現：

1 log4j:WARN No appenders could be found for logger (org.apache.ibatis.logging.LogFactory).2 log4j:WARN Please initialize the log4j system PRoperly.

這個問題是因為我們的log4j.properties文件配置不夠完整，所以我們給它配置齊了就不會再出現這個問題。log4j.properties不完整配置如下：

1 log4j.rootLogger=DEBUG, stdout 2  3 log4j.appender.stdout=org.apache.log4j.ConsoleAppender 4 log4j.appender.stdout.layout=org.apache.log4j.PatternLayout 5 log4j.appender.stdout.layout.ConversionPattern=%c{1} - %m%n 6  7 log4j.logger.java.sql.PreparedStatement=DEBUG 

完整配置如下：

 1 log4j.rootLogger=CONSOLE,FILE 2 log4j.addivity.org.apache=true 3  4 # 應用于控制臺 5 log4j.appender.CONSOLE=org.apache.log4j.ConsoleAppender 6 log4j.appender.CONSOLE.Threshold=INFO 7 log4j.appender.CONSOLE.Target=System.out 8 log4j.appender.CONSOLE.Encoding=GBK 9 log4j.appender.CONSOLE.layout=org.apache.log4j.PatternLayout10 log4j.appender.CONSOLE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n11 12 # 每天新建日志13 log4j.appender.A1=org.apache.log4j.DailyRollingFileAppender14 log4j.appender.A1.File=C:/log4j/log15 log4j.appender.A1.Encoding=GBK16 log4j.appender.A1.Threshold=DEBUG17 log4j.appender.A1.DatePattern='.'yyyy-MM-dd18 log4j.appender.A1.layout=org.apache.log4j.PatternLayout19 log4j.appender.A1.layout.ConversionPattern=%d{ABSOLUTE} %5p %c{1}:%L : %m%n20 21 #應用于文件22 log4j.appender.FILE=org.apache.log4j.FileAppender23 log4j.appender.FILE.File=C:/log4j/file.log24 log4j.appender.FILE.Append=false25 log4j.appender.FILE.Encoding=GBK26 log4j.appender.FILE.layout=org.apache.log4j.PatternLayout27 log4j.appender.FILE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n28 29 # 應用于文件回滾30 log4j.appender.ROLLING_FILE=org.apache.log4j.RollingFileAppender31 log4j.appender.ROLLING_FILE.Threshold=ERROR32 log4j.appender.ROLLING_FILE.File=rolling.log33 log4j.appender.ROLLING_FILE.Append=true34 log4j.appender.CONSOLE_FILE.Encoding=GBK35 log4j.appender.ROLLING_FILE.MaxFileSize=10KB36 log4j.appender.ROLLING_FILE.MaxBackupIndex=137 log4j.appender.ROLLING_FILE.layout=org.apache.log4j.PatternLayout38 log4j.appender.ROLLING_FILE.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n39 40 #自定義Appender41 log4j.appender.im = net.cybercorlin.util.logger.appender.IMAppender42 log4j.appender.im.host = mail.cybercorlin.net43 log4j.appender.im.username = username44 log4j.appender.im.passWord = password45 log4j.appender.im.recipient = yyflyons@163.com46 log4j.appender.im.layout=org.apache.log4j.PatternLayout47 log4j.appender.im.layout.ConversionPattern =[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n48 49 #應用于socket50 log4j.appender.SOCKET=org.apache.log4j.RollingFileAppender51 log4j.appender.SOCKET.RemoteHost=localhost52 log4j.appender.SOCKET.Port=500153 log4j.appender.SOCKET.LocationInfo=true54 # Set up for Log Facter 555 log4j.appender.SOCKET.layout=org.apache.log4j.PatternLayout56 log4j.appender.SOCET.layout.ConversionPattern=[start]%d{DATE}[DATE]%n%p[PRIORITY]%n%x[NDC]%n%t[THREAD]%n%c[CATEGORY]%n%m[MESSAGE]%n%n57 # Log Factor 5 Appender58 log4j.appender.LF5_APPENDER=org.apache.log4j.lf5.LF5Appender59 log4j.appender.LF5_APPENDER.MaxNumberOfRecords=200060 61 # 發送日志給郵件62 log4j.appender.MAIL=org.apache.log4j.net.SMTPAppender63 log4j.appender.MAIL.Threshold=FATAL64 log4j.appender.MAIL.BufferSize=1065 log4j.appender.MAIL.From=yyflyons@163.com66 log4j.appender.MAIL.SMTPHost=www.wusetu.com67 log4j.appender.MAIL.Subject=Log4J Message68 log4j.appender.MAIL.To=yyflyons@126.com69 log4j.appender.MAIL.layout=org.apache.log4j.PatternLayout70 log4j.appender.MAIL.layout.ConversionPattern=[framework] %d - %c -%-4r [%t] %-5p %c %x - %m%n

再次運行你的程序，你會發現Log4j的警告消失了。不過發現以前的Log4j控制臺信息也沒有了，其實只要把上面詳細配置的log4j.rootLogger=CONSOLE,FILE改為log4j.rootLogger=DEBUG,CONSOLE,FILE，你就發現，控制臺信息又回來了。

1 log4j.rootLogger=CONSOLE,FILE2 #log4j.rootLogger=DEBUG,CONSOLE,FILE3 log4j.addivity.org.apache=true