log4j log Output mode profile Log4j.properties usage Personal Insights

Log level Size: DEBUG < INFO < WARN < ERROR < FATAL

1, the use of Log4j.rootlogger

#log4j. Rootlogger is configured with an output #log4j that is greater than or equal to the current level of log information. Rootlogger Usage: (note appendername can be one or more) #log4j. Rootlogger = Log level,                            Appendername1,appendername2,.... #log4j. appender.appendername1 defines the output of the log in two ways: one is command line output or console output, and the other is file mode save # 1) The console output should be configured as Org.apache.log4j.PatternLayout # 2) text save should be configured as Org.apache.log4j.DailyR Ollingfileappender # 3) You can also customize the Appender class #log4j. Appender.appenderName1.layout.ConversionPattern The format of the log content is defined #log4j. appender.appenderName1.file defines the file name #log4j for the log file. Appender.appenderName1.DatePattern
Defines the time interval for log file rebuilds and, if set to days, regenerates a new log file daily. # The old log file is saved with a new file name = Log4j.appender.appenderName1.file + log4j.appender.append 
Ername1.datepattern Log4j.rootlogger = Info,stdout,file Log4j.appender.stdout=org.apache.log4j.consoleappender Log4j.appender.stdout.layout=org.apache.log4j.patternlayout log4j.appender.stdout.layout.conversionpattern=[%p] [%d{yyyy-mm-dd HH:mm:ss}] [%c{1}:%l] -%m%n Log4j.appender.file = Org.apache.log4j.DailyRollingFileAppender log4j.appender.file.file=d\:\\log\\info (+). Log log4j.appender.file.datepattern= '. '
YYYY-MM-DD Log4j.appender.file.layout=org.apache.log4j.patternlayout
 LOG4J.APPENDER.FILE.LAYOUT.CONVERSIONPATTERN=[%P][%D{YYYY-MM-DD Hh:mm:ss}][%c{1}:%l]-%m%n

The above code, the information, WARN, ERROR, FATAL these four levels of log messages in the console print out, and as a file saved to D:\log\info (+). Log

2. Log4j.logger usage is as follows

# 1) log4j.logger. Package name = Log level, appendername1,appendername2,.... # defines the log output of all classes in the name of the package # 2) Log4j.logger. class full name with package name = Log level, appendername1,appendername2,.... # defines the log output of the specified class # 3) log4j.log Ger. Log Object logger named name = Log level, appendername1,appendername2,.... # defines the output of a log for a named name, such as: # log4j . Logger. Log1 refers to the log output that defines the log object that is obtained through Logger.getlogger ("Log1") #以log4j. Logger. Package name for example Log4j.logger.edu.service.impl = Error,service _stdout,service_logfile Log4j.appender.service_stdout=org.apache.log4j.consoleappender Log4j.appender.service_ Stdout.layout=org.apache.log4j.patternlayout log4j.appender.service_stdout.layout.conversionpattern=[%p][%d{
YYYY-MM-DD hh:mm:ss}][%c{1}:%l]-%m%n log4j.appender.service_logfile = Org.apache.log4j.DailyRollingFileAppender Log4j.appender.service_logfile.file=d:\\log\\service.log Log4j.appender.service_logfile. Datepattern= '. ' YYYY-MM-DD Log4j.appender.service_logfile.layout=org.apache.log4j.patteRnlayout log4j.appender.service_logfile.layout.conversionpattern=[%p][%d{yyyy-mm-dd HH:mm:ss}][%C{1}:%L]-%m%n
 

Package Edu.service.impl;

Import Java.io.File;
Import Java.io.FileInputStream;
Import Java.io.FileOutputStream;
Import Java.io.InputStream;
Import Java.util.Iterator;
Import java.util.List;

Import Org.apache.commons.lang.RandomStringUtils;
Import Org.apache.log4j.Logger;
Import Org.apache.poi.hssf.usermodel.HSSFRow;
Import Org.apache.poi.hssf.usermodel.HSSFSheet;
Import Org.apache.poi.hssf.usermodel.HSSFWorkbook;

Import Utils. StringUtils;

Import Edu.dao.UserDao;
Import Edu.po.User;
Import Edu.service.UserService;
Import Edu.vo.UserVO;

public class Userserviceimpl implements UserService {
	
	private Logger Logger = Logger.getlogger ( Userserviceimpl.class);

.....

Through the configuration of the above code, the private Logger Logger = Logger.getlogger (Userserviceimpl.class); The error, fatal information for this log object is output and saved to the D:\log\service.log file in the console.