[TOC] # 創建一個java工程  **在項目的根目錄下創建** ~~~ ### 設置### #設置logger級別DEBUG、INFO、WRNING、ERROR和輸出格式A、B、C或D log4j.rootLogger = debug,stdout,D,E ### 輸出信息到控制抬 ### log4j.appender.stdout = org.apache.log4j.ConsoleAppender log4j.appender.stdout.Target = System.out log4j.appender.stdout.layout = org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern = [%-5p] %d{yyyy-MM-dd HH:mm:ss,SSS} method:%l%n%m%n ### 輸出DEBUG 級別以上的日志到=/Users/jdxia/Desktop/website/log4j/log.log ### log4j.appender.D = org.apache.log4j.DailyRollingFileAppender log4j.appender.D.File = /Users/jdxia/Desktop/website/log4j/log.log log4j.appender.D.Append = true log4j.appender.D.Threshold = DEBUG log4j.appender.D.layout = org.apache.log4j.PatternLayout log4j.appender.D.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n ### 輸出ERROR 級別以上的日志到=/Users/jdxia/Desktop/website/log4j/error.log ### log4j.appender.E = org.apache.log4j.DailyRollingFileAppender log4j.appender.E.File =/Users/jdxia/Desktop/website/log4j/error.log log4j.appender.E.Append = true log4j.appender.E.Threshold = ERROR log4j.appender.E.layout = org.apache.log4j.PatternLayout log4j.appender.E.layout.ConversionPattern = %-d{yyyy-MM-dd HH:mm:ss} [ %t:%r ] - [ %p ] %m%n ~~~ **設置日志內容** ~~~ package com.jdxia; import org.apache.log4j.Logger; public class Test { //獲取日志記錄器Logger，名字為本類類名 private static Logger log = Logger.getLogger(Test.class); public static void main(String[] args) { //記錄debug級別的日志 log.debug("this is debug message"); //記錄info級別的日志 log.info("this is info message"); //記錄error級別的日志 log.error("this is error message"); } } ~~~ **輸出結果** 1. 首先是控制臺的信息  2. 再來看輸出文件  發現已按照要求輸出到對應的文檔中去了