关于log4j知识

今天下午接触到log4j知识，花了几个小时，百度了一圈，总算是懂了一些。

log4j的作用：log4j是一个日志输出的插件专门用来进行日志管理的，根据我的理解就是用来执行我们用来检测程序bug的System.out.println()语句的，不过更为简洁，格式也更好判断，利用相关的符号，可以精确到某一行的问题点。

在log4j中，我们刚开始是要利用到log4j的jar包，可以去Apache官网下载，http://www.apache.org/ ，下载后进入到到java中执行build path 加入jar包即可。

log4j有两种使用的形式，一种是利用我们建立的log4j.properties文件进行相关的配置，另外一种是利用log4j2.xml文件进行配置。配置好之后我们就可以写程序了。

 1 package com.sxt.Log4j;
 2 
 3 import org.apache.logging.log4j.LogManager;
 4 import org.apache.logging.log4j.Logger;
 5 
 6 public class TestLog4j {
 7         private static Logger logger = LogManager.getLogger(TestLog4j.class.getName());
 8     
 9         public void getTestLog4j() {
10             
11             logger.info("我是info信息");
12             logger.error("我是error");
13             logger.fatal("我是fatal");
14         }
15         
16         public static void main(String[] args) {
17             new TestLog4j().getTestLog4j();
18         }
19 }

log4j，可以利用properties的配置语句实现大的功能。

 1 #OFF,systemOut,logFile,logDailyFile,logRollingFile,logMail,logDB,ALL,socket,im 
 2 log4j.rootLogger =ALL,systemOut,logFile,logDailyFile,logRollingFile,logMail,logDB,socket,im
 3  
 4 #输出到控制台 
 5 log4j.appender.systemOut = org.apache.log4j.ConsoleAppender 
 6 log4j.appender.systemOut.layout = org.apache.log4j.PatternLayout 
 7 log4j.appender.systemOut.layout.ConversionPattern = [%-5p][%-22d{yyyy-MM-dd HH:mm:ss S}][%l]%n%m%n 
 8 log4j.appender.systemOut.Threshold = DEBUG 
 9 log4j.appender.systemOut.ImmediateFlush = TRUE 
10 log4j.appender.systemOut.Target = System.out 
11  
12 #输出到文件 
13 log4j.appender.logFile = org.apache.log4j.FileAppender 
14 log4j.appender.logFile.layout = org.apache.log4j.PatternLayout 
15 log4j.appender.logFile.layout.ConversionPattern = [%-5p][%-22d{yyyy-MM-dd HH:mm:ss S}][%l]%n%m%n 
16 log4j.appender.logFile.Threshold = DEBUG 
17 log4j.appender.logFile.ImmediateFlush = TRUE 
18 log4j.appender.logFile.Append = TRUE 
19 log4j.appender.logFile.File = D://opt/ftp/vtm-om/logs/FileAppender.log
20 log4j.appender.logFile.Encoding = UTF-8 
21  
22 #定期回滚日志文件(logDailyFile)
23 log4j.appender.logDailyFile = org.apache.log4j.DailyRollingFileAppender 
24 log4j.appender.logDailyFile.layout = org.apache.log4j.PatternLayout 
25 log4j.appender.logDailyFile.layout.ConversionPattern = [%-5p][%-22d{yyyy-MM-dd HH:mm:ss S}][%l]%n%m%n 
26 log4j.appender.logDailyFile.Threshold = DEBUG 
27 log4j.appender.logDailyFile.ImmediateFlush = TRUE 
28 log4j.appender.logDailyFile.Append = TRUE 
29 log4j.appender.logDailyFile.File = D://opt/ftp/vtm-om/logs/DailyRollingFileAppender
30 log4j.appender.logDailyFile.DatePattern = '.'yyyyMMddHHmmss'.log' 
31 log4j.appender.logDailyFile.Encoding = UTF-8 
32  
33 #回滚文件(logRollingFile)
34 log4j.appender.logRollingFile = org.apache.log4j.RollingFileAppender 
35 log4j.appender.logRollingFile.layout = org.apache.log4j.PatternLayout 
36 log4j.appender.logRollingFile.layout.ConversionPattern = [%-5p][%-22d{yyyy-MM-dd HH:mm:ss S}][%l]%n%m%n 
37 log4j.appender.logRollingFile.Threshold = DEBUG 
38 log4j.appender.logRollingFile.ImmediateFlush = TRUE 
39 log4j.appender.logRollingFile.Append = TRUE 
40 log4j.appender.logRollingFile.File = D://opt/ftp/vtm-om/logs/RollingFileAppender.log
41 log4j.appender.logRollingFile.MaxFileSize = 1MB 
42 log4j.appender.logRollingFile.MaxBackupIndex = 10 
43 log4j.appender.logRollingFile.Encoding = UTF-8 
44  
45 #发送日志到指定邮件
46 log4j.appender.logMail = org.apache.log4j.net.SMTPAppender 
47 log4j.appender.logMail.layout = org.apache.log4j.HTMLLayout 
48 log4j.appender.logMail.layout.LocationInfo = TRUE 
49 log4j.appender.logMail.layout.Title = Struts2 Mail LogFile 
50 log4j.appender.logMail.Threshold = DEBUG 
51 log4j.appender.logMail.SMTPDebug = FALSE 
52 log4j.appender.logMail.SMTPHost = smtp.163.com
53 log4j.appender.logMail.From = ****@163.com
54 log4j.appender.logMail.To = ****@qq.com 
55 #log4j.appender.logMail.Cc = ****@qq.com
56 log4j.appender.logMail.Bcc = ****@qq.com 
57 log4j.appender.logMail.SMTPUsername = ****@163.com
58 log4j.appender.logMail.SMTPPassword = ****
59 log4j.appender.logMail.Subject = Log4j Log Messages
60 log4j.appender.logMail.BufferSize = 1024 
61 log4j.appender.logMail.SMTPAuth = TRUE 
62  
63 #将日志登录到MySQL数据库 
64 log4j.appender.logDB = org.apache.log4j.jdbc.JDBCAppender 
65 log4j.appender.logDB.layout = org.apache.log4j.PatternLayout 
66 log4j.appender.logDB.Driver = com.mysql.jdbc.Driver
67 log4j.appender.logDB.URL = jdbc:mysql://192.168.1.71:3306/test
68 log4j.appender.logDB.User = root
69 log4j.appender.logDB.Password = 123456
70 log4j.appender.logDB.Sql = INSERT log_info(project_name,create_date,level,category,file_name,thread_name,line,all_category,message)values('souvc','%d{yyyy-MM-dd HH:mm:ss}','%p','%c','%F','%t','%L','%l','%m')
71  
72 # 应用于socket
73 log4j.appender.socket=org.apache.log4j.RollingFileAppender
74 log4j.appender.socket.RemoteHost=localhost
75 log4j.appender.socket.Port=5001
76 log4j.appender.socket.LocationInfo=true
77 # Set up for Log Factor 5
78 log4j.appender.socket.layout=org.apache.log4j.PatternLayout
79 log4j.appender.socket.layout.ConversionPattern=[%-5p] %d(%r) --> [%t] %l: %m %x %n
80 # Log Factor 5 Appender
81 log4j.appender.LF5_APPENDER=org.apache.log4j.lf5.LF5Appender
82 log4j.appender.LF5_APPENDER.MaxNumberOfRecords=2000
83  
84  
85 # 自定义Appender
86 log4j.appender.im = com.souvc.logger.appender.IMAppender
87 log4j.appender.im.host = localhost
88 log4j.appender.im.username = username
89 log4j.appender.im.password = password
90 log4j.appender.im.recipient = souvc@souvc.com
91 log4j.appender.im.layout=org.apache.log4j.PatternLayout
92 log4j.appender.im.layout.ConversionPattern=[%-5p] %d(%r) --> [%t] %l: %m %x %n