1. First configure the jdk

Choose Preferences----

Find the location of your own jdk

2. Configure Tomcat

window-----preferences-------

Find your own tomcat location

3. Right click the project, build path -------- > configure build path

4. Import log4j-1.2.14.jar

Right click log4j-1.2.14.jar file build path ----- > add to build path

Create a log4j.log file in the root directory of the project, and import the log4j.properties file in the src directory

The code of log4j.properties file is as follows

#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

Create a package org.jsoft.log

Create a TestLog class under the package

package org.jsoft.log;

import org.apache.log4j.*;
/**
 * @author Administrator
 * @version 2018-1-9 9:14:11 am
 */
public class TestLog {
    
    public static void main(String[] args) {
        //Acquisition recorder
        new TestLog().getLog();
    }
    public void getLog(){
        Logger l = Logger.getLogger(TestLog.class);
        l.info("You moved my people");
    }
}

Run. You can see that the log is printed out in log4j.log

WARN No appenders could be found for logger (org.jsoft.log.TestLog).

This error occurred because the log4j.properties file was not imported