使用java.util.logging.Logger时如何在文本文件中写日志

I have a situation in which I want to write all logs created by me to write into a text file.

我有一种情况，我想写下我创建的所有日志写入文本文件。

we are using java.util.logging.Logger API for generating the logs.

我们使用java.util.logging.Logger API来生成日志。

I tried

我试过了

private static Logger logger = Logger.getLogger(className.class.getName());
FileHandler fh;   
fh = new FileHandler("C:/className.log");   
logger.addHandler(fh);

But still getting my logs on console only....

但仍然只在控制台上登录....

8 个解决方案

#1

182

Try this sample. It works for me.

试试这个样本。这个对我有用。

public static void main(String[] args) {  

    Logger logger = Logger.getLogger("MyLog");  
    FileHandler fh;  

    try {  

        // This block configure the logger with handler and formatter  
        fh = new FileHandler("C:/temp/test/MyLogFile.log");  
        logger.addHandler(fh);
        SimpleFormatter formatter = new SimpleFormatter();  
        fh.setFormatter(formatter);  

        // the following statement is used to log any messages  
        logger.info("My first log");  

    } catch (SecurityException e) {  
        e.printStackTrace();  
    } catch (IOException e) {  
        e.printStackTrace();  
    }  

    logger.info("Hi How r u?");  

}

Produces the output at MyLogFile.log

在MyLogFile.log生成输出

Apr 2, 2013 9:57:08 AM testing.MyLogger main  
INFO: My first log  
Apr 2, 2013 9:57:08 AM testing.MyLogger main  
INFO: Hi How r u?

Edit:

编辑：

To remove the console handler, use

要删除控制台处理程序，请使用

logger.setUseParentHandlers(false);

since the ConsoleHandler is registered with the parent logger from which all the loggers derive.

因为ConsoleHandler是在父记录器中注册的，所有记录器都来自该记录器。

#2

Firstly, where did you define your logger and from what class\method trying to call it? There is a working example, fresh baked:

首先，您在哪里定义了您的记录器以及从哪个类\方法尝试调用它？有一个工作的例子，新鲜出炉：

public class LoggingTester {
    private final Logger logger = Logger.getLogger(LoggingTester.class
            .getName());
    private FileHandler fh = null;

    public LoggingTester() {
        //just to make our log file nicer :)
        SimpleDateFormat format = new SimpleDateFormat("M-d_HHmmss");
        try {
            fh = new FileHandler("C:/temp/test/MyLogFile_"
                + format.format(Calendar.getInstance().getTime()) + ".log");
        } catch (Exception e) {
            e.printStackTrace();
        }

        fh.setFormatter(new SimpleFormatter());
        logger.addHandler(fh);
    }

    public void doLogging() {
        logger.info("info msg");
        logger.severe("error message");
        logger.fine("fine message"); //won't show because to high level of logging
    }
}

In your code you forgot to define the formatter, if you need simple one you can do it as I mentioned above, but there is another option, you can format it by yourself, there is an example (just insert it instead of this line fh.setFormatter(new SimpleFormatter()) following code):

在您的代码中，您忘记定义格式化程序，如果您需要简单的格式化程序，您可以按照上面的说明进行操作，但还有另一个选项，您可以自己格式化，有一个示例（只需插入而不是此行fh） .setFormatter（新的SimpleFormatter（））代码）：

fh.setFormatter(new Formatter() {
            @Override
            public String format(LogRecord record) {
                SimpleDateFormat logTime = new SimpleDateFormat("MM-dd-yyyy HH:mm:ss");
                Calendar cal = new GregorianCalendar();
                cal.setTimeInMillis(record.getMillis());
                return record.getLevel()
                        + logTime.format(cal.getTime())
                        + " || "
                        + record.getSourceClassName().substring(
                                record.getSourceClassName().lastIndexOf(".")+1,
                                record.getSourceClassName().length())
                        + "."
                        + record.getSourceMethodName()
                        + "() : "
                        + record.getMessage() + "\n";
            }
        });

Or any other modification whatever you like. Hope it helps.

或任何其他任何你喜欢的修改。希望能帮助到你。

#3

A good library available named log4j for Java.
This will provide numerous feature. Go through link and you will find your solution.

一个名为log4j for Java的好库。这将提供众多功能。通过链接，您将找到您的解决方案。

#4

Maybe this is what you need...

也许这就是你需要的......

import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.io.IOException;
import java.util.logging.FileHandler;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JOptionPane;
import javax.swing.JPanel;

/**
 * LogToFile class
 * This class is intended to be use with the default logging class of java
 * It save the log in an XML file  and display a friendly message to the user
 * @author Ibrabel <ibrabel@gmail.com>
 */
public class LogToFile {

    protected static final Logger logger=Logger.getLogger("MYLOG");
    /**
     * log Method 
     * enable to log all exceptions to a file and display user message on demand
     * @param ex
     * @param level
     * @param msg 
     */
    public static void log(Exception ex, String level, String msg){

        FileHandler fh = null;
        try {
            fh = new FileHandler("log.xml",true);
            logger.addHandler(fh);
            switch (level) {
                case "severe":
                    logger.log(Level.SEVERE, msg, ex);
                    if(!msg.equals(""))
                        JOptionPane.showMessageDialog(null,msg,
                            "Error", JOptionPane.ERROR_MESSAGE);
                    break;
                case "warning":
                    logger.log(Level.WARNING, msg, ex);
                    if(!msg.equals(""))
                        JOptionPane.showMessageDialog(null,msg,
                            "Warning", JOptionPane.WARNING_MESSAGE);
                    break;
                case "info":
                    logger.log(Level.INFO, msg, ex);
                    if(!msg.equals(""))
                        JOptionPane.showMessageDialog(null,msg,
                            "Info", JOptionPane.INFORMATION_MESSAGE);
                    break;
                case "config":
                    logger.log(Level.CONFIG, msg, ex);
                    break;
                case "fine":
                    logger.log(Level.FINE, msg, ex);
                    break;
                case "finer":
                    logger.log(Level.FINER, msg, ex);
                    break;
                case "finest":
                    logger.log(Level.FINEST, msg, ex);
                    break;
                default:
                    logger.log(Level.CONFIG, msg, ex);
                    break;
            }
        } catch (IOException | SecurityException ex1) {
            logger.log(Level.SEVERE, null, ex1);
        } finally{
            if(fh!=null)fh.close();
        }
    }

    public static void main(String[] args) {

        /*
            Create simple frame for the example
        */
        JFrame myFrame = new JFrame();
        myFrame.setTitle("LogToFileExample");
        myFrame.setSize(300, 100);
        myFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        myFrame.setLocationRelativeTo(null);
        JPanel pan = new JPanel();
        JButton severe = new JButton("severe");
        pan.add(severe);
        JButton warning = new JButton("warning");
        pan.add(warning);
        JButton info = new JButton("info");
        pan.add(info);

        /*
            Create an exception on click to use the LogToFile class
        */
        severe.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent ae) {
                int j = 20, i = 0;
                try {
                    System.out.println(j/i);
                } catch (ArithmeticException ex) {
                    log(ex,"severe","You can't divide anything by zero");
                }

            }

        });

        warning.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent ae) {
                int j = 20, i = 0;
                try {
                    System.out.println(j/i);
                } catch (ArithmeticException ex) {
                    log(ex,"warning","You can't divide anything by zero");
                }

            }

        });

        info.addActionListener(new ActionListener(){

            @Override
            public void actionPerformed(ActionEvent ae) {
                int j = 20, i = 0;
                try {
                    System.out.println(j/i);
                } catch (ArithmeticException ex) {
                    log(ex,"info","You can't divide anything by zero");
                }

            }

        });

        /*
            Add the JPanel to the JFrame and set the JFrame visible
        */
        myFrame.setContentPane(pan);
        myFrame.setVisible(true);
    }
}

#5

Location of log file can be control through logging.properties file. And it can be passed as JVM parameter ex : java -Djava.util.logging.config.file=/scratch/user/config/logging.properties

可以通过logging.properties文件控制日志文件的位置。它可以作为JVM参数传递：java -Djava.util.logging.config.file = / scratch / user / config / logging.properties

Details: https://docs.oracle.com/cd/E23549_01/doc.1111/e14568/handler.htm

详细信息：https：//docs.oracle.com/cd/E23549_01/doc.1111/e14568/handler.htm

Configuring the File handler

配置文件处理程序

To send logs to a file, add FileHandler to the handlers property in the logging.properties file. This will enable file logging globally.

要将日志发送到文件，请将FileHandler添加到logging.properties文件中的handlers属性。这将启用全局文件记录。

handlers= java.util.logging.FileHandler Configure the handler by setting the following properties:

handlers = java.util.logging.FileHandler通过设置以下属性来配置处理程序：

java.util.logging.FileHandler.pattern=<home directory>/logs/oaam.log
java.util.logging.FileHandler.limit=50000
java.util.logging.FileHandler.count=1
java.util.logging.FileHandler.formatter=java.util.logging.SimpleFormatter

java.util.logging.FileHandler.pattern specifies the location and pattern of the output file. The default setting is your home directory.

java.util.logging.FileHandler.pattern指定输出文件的位置和模式。默认设置是您的主目录。

java.util.logging.FileHandler.limit specifies, in bytes, the maximum amount that the logger writes to any one file.

java.util.logging.FileHandler.limit以字节为单位指定记录器写入任何一个文件的最大数量。

java.util.logging.FileHandler.count specifies how many output files to cycle through.

java.util.logging.FileHandler.count指定要循环的输出文件的数量。

java.util.logging.FileHandler.formatter specifies the java.util.logging formatter class that the file handler class uses to format the log messages. SimpleFormatter writes brief "human-readable" summaries of log records.

java.util.logging.FileHandler.formatter指定文件处理程序类用于格式化日志消息的java.util.logging格式化程序类。 SimpleFormatter编写简短的“人类可读”日志记录摘要。

To instruct java to use this configuration file instead of $JDK_HOME/jre/lib/logging.properties:

要指示java使用此配置文件而不是$ JDK_HOME / jre / lib / logging.properties：

java -Djava.util.logging.config.file=/scratch/user/config/logging.properties

#6

int SIZE = "<intialize-here>"
int ROTATIONCOUNT = "<intialize-here>"

Handler handler = new FileHandler("test.log", SIZE, LOG_ROTATIONCOUNT);
logger.addHandler(handler);     // for your code.. 

// you can also set logging levels
Logger.getLogger(this.getClass().getName()).log(Level.[...]).addHandler(handler);

#7

import java.io.IOException;
import org.apache.log4j.Appender;
import org.apache.log4j.FileAppender;
import org.apache.log4j.Logger;
import org.apache.log4j.SimpleLayout;

/**
 * @author Kiran
 * 
 */
public class MyLogger {

    public MyLogger() {
    }

    public static void main(String[] args) {
        Logger logger = Logger.getLogger("MyLog");
        Appender fh = null;
        try {
            fh = new FileAppender(new SimpleLayout(), "MyLogFile.log");
            logger.addAppender(fh);
            fh.setLayout(new SimpleLayout());
            logger.info("My first log");
        } catch (SecurityException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        logger.info("Hi How r u?");
    }
}

#8

Here is my logging class based on the accepted answer:

这是我根据接受的答案记录的日志类：

import java.io.File;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.logging.*;

public class ErrorLogger
{
    private Logger logger;

    public ErrorLogger()
    {
        logger = Logger.getAnonymousLogger();

        configure();
    }

    private void configure()
    {
        try
        {
            String logsDirectoryFolder = "logs";
            Files.createDirectories(Paths.get(logsDirectoryFolder));
            FileHandler fileHandler = new FileHandler(logsDirectoryFolder + File.separator + getCurrentTimeString() + ".log");
            logger.addHandler(fileHandler);
            SimpleFormatter formatter = new SimpleFormatter();
            fileHandler.setFormatter(formatter);
        } catch (IOException exception)
        {
            exception.printStackTrace();
        }

        addCloseHandlersShutdownHook();
    }

    private void addCloseHandlersShutdownHook()
    {
        Runtime.getRuntime().addShutdownHook(new Thread(() ->
        {
            // Close all handlers to get rid of empty .LCK files
            for (Handler handler : logger.getHandlers())
            {
                handler.close();
            }
        }));
    }

    private String getCurrentTimeString()
    {
        DateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd-HH-mm-ss");
        return dateFormat.format(new Date());
    }

    public void log(Exception exception)
    {
        logger.log(Level.SEVERE, "", exception);
    }
}

#1

182