Log4J无法正常工作？

Question

我是Log4J的新手.我想让这个记录器工作.我下载了.JAR文件,我已将其构建到Referenced Libraries中,可以打开文件夹并在那里查看.所以我认为它已经内置到我的项目中.

我想我错过了如何声明记录器,以便我可以在下面使用它.我从stackoverflow获得的一些代码.

问题:我错过了Log4J声明的哪一部分,以便我可以在我的简单示例中将其用作记录器？

码:

import java.io.*;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;
import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class TestLogs {
    private static Logger logger = Logger.getLogger(FileChooserDemo.class.getName());

    FileHandler fh;   

    public TestLogs() {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
            fh = new FileHandler("C:\\Users\\itpr13266\\Desktop\\MyNewLogFile.log");   
            logger.addHandler(fh);
            logger.info("Logging an INFO-level message");
            logger.warning("Your file cannot be written!!");
        } catch (Exception ex) {
            Logger.getLogger(FileChooserDemo.class.getName()).log(Level.SEVERE, null, ex);
        }
    }

    private void LogTester() {
         Logger.getRootLogger().getLoggerRepository().resetConfiguration();
         ConsoleAppender console = new ConsoleAppender(); //create appender
          //configure the appender
          String PATTERN = "%d [%p|%c|%C{1}] %m%n";
          console.setLayout(new PatternLayout(PATTERN)); 
          console.setThreshold(Level.FATAL);
          console.activateOptions();
          //add appender to any Logger (here is root)
          Logger.getRootLogger().addAppender(console);

          FileAppender fa = new FileAppender();
          fa.setName("FileLogger");
          fa.setFile("mylog.log");
          fa.setLayout(new PatternLayout("%d %-5p [%c{1}] %m%n"));
          fa.setThreshold(Level.DEBUG);
          fa.setAppend(true);
          fa.activateOptions();

          //add appender to any Logger (here is root)
          Logger.getRootLogger().addAppender(fa)    
    }

    public static void main(String[] args) {
       TestLogs tls = new TestLogs();
       tls.LogTester();
     }
}

新图像 - 我重建了路径,并将它们放在文件结构中稍微不同的位置.但错误仍然存​​在.

有效的代码---但是如何将其记录到计算机上的文本文件中.

package TestMenu;

import org.apache.log4j.*;

import javax.swing.*;

public class TestLogs {
    private static Logger logger = Logger.getLogger(TestLogs.class.getName());

    public TestLogs() {
        try {
            UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel");
            UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
        } catch (Exception ex) {
        }
    }

    private void LogTester() {
         logger.info("It works");
         TestLogs tls = new TestLogs();
    }

    public static void main(String[] args) {
       TestLogs tls = new TestLogs();
       tls.LogTester();
     }
}

至少log4j正在工作,但是如何更改属性文件,以便我可以将所有警告,信息和文件记录到控制台？

Log4j属性:

# Root logger option
log4j.rootLogger=INFO, stdout

# Direct log messages to stdout
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=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

新图像 - 不工作 - 底部显示错误

错误:

log4j:WARN No appenders could be found for logger (TestMenu.TestLogs).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

Answer 1

您正在尝试使用java util logging而不是log4j.你需要导入

import org.apache.log4j.Logger;

我看到的另一件事是你的代码错了

改变这个:

private static Logger logger = Logger.getLogger(FileChooserDemo.class.getName());

至

private static Logger logger = Logger.getLogger(TestLogs.class.getName());

这是一个例子

package com.vkg;

import org.apache.log4j.Logger;

public class TestLogs {
    private static Logger logger = Logger.getLogger(TestLogs.class.getName());

    public static void main(String[] args) {
        logger.info("It works");
        TestLogs tls = new TestLogs();
    }
}

一个基本的log4j配置文件

  # Root logger 
log4j.rootLogger=INFO, file, stdout

# Write to file
log4j.appender.file=org.apache.log4j.RollingFileAppender
log4j.appender.file.File=[sompath to your log file e.g. C:\\mylog.log]
log4j.appender.file.MaxFileSize=50MB
log4j.appender.file.MaxBackupIndex=1
log4j.appender.file.layout=org.apache.log4j.PatternLayout
log4j.appender.file.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

# Write to console
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=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L - %m%n

并输出

2014-05-12 13:18:01 INFO  TestLogs:9 - It works

下图显示了log4j.properties的保存位置