1.先将jdk配置一下
选Preferences----
找到自己的jdk所在的位置
2.配置Tomcat
window-----preferences-------
找到自己的tomcat所在位置
3.项目右键，build path--------->configure build path
4.导入log4j-1.2.14.jar
右键点击log4j-1.2.14.jar文件build path----->add to build path
项目根目录下创建一个log4j.log的文件，同时在src目录下导入log4j.properties文件
log4j.properties文件代码如下
#log4j.rootLogger = DEBUG, a1 log4j.rootLogger = INFO, A1 #log4j.rootLogger = ERROR, A1 #\u8fd9\u91cc\u5b9a\u4e49\u7684\u662ferror\u7ea7\u522b\u7684\uff0c\u5176\u5b9e\u7528info\u7ea7\u7684\u5c31\u53ef\u4ee5\u4e86\uff0c\u53cd\u6b63\u67095\u4e2a\u7ea7\u522b\u4f60\u81ea\u5df1\u770b\u7740\u7528\uff1b #log4j.appender.A1 = org.apache.log4j.ConsoleAppender log4j.appender.A1 = org.apache.log4j.FileAppender log4j.appender.A1 = org.apache.log4j.RollingFileAppender log4j.appender.A1.File =log4j.log #\u5b9a\u4e49\u65e5\u5fd7\u7684\u5b58\u653e\u8def\u5f84\u548c\u6587\u4ef6\u540d\uff1b log4j.appender.A1.MaxFileSize=500KB #\u5f53log\u6587\u4ef6\u5927\u4e8e500K\u7684\u65f6\u5019\u5220\u9664\u91cd\u65b0\u5efa\uff1b log4j.appender.A1.MaxBackupIndex=10 log4j.appender.A1.layout = org.apache.log4j.PatternLayout #\u4f7f\u7528\u7684\u662f\u81ea\u5b9a\u4e49\u7684\u65e5\u5fd7\u683c\u5f0f\uff0c\u4e0b\u9762\u5c31\u662f\u81ea\u5b9a\u4e49\u7684\u4e00\u4e9b\u53c2\u6570\u54af\uff1b #log4j.appender.A1.layout.ConversionPattern = %-4r [%t] %-5p %c %x - %m%n log4j.appender.A1.layout.ConversionPattern = [%d] [%t] %m%n