how tomcat works 七 日志记录器

标签：tomcat   读书笔记   日志记录器   timestamp   

Logger接口

Tomcat中的日志记录器都必须实现org.apache.catalina.Logger接口。

package org.apache.catalina;

import java.beans.PropertyChangeListener;

public interface Logger {
    
    public static final int FATAL = Integer.MIN_VALUE;
    public static final int ERROR = 1;
    public static final int WARNING = 2;
    public static final int INFORMATION = 3;
    public static final int DEBUG = 4;

    public Container getContainer();
    public void setContainer(Container container);
    public String getInfo();
    public int getVerbosity();
    public void setVerbosity(int verbosity);
    public void addPropertyChangeListener(PropertyChangeListener listener);

    public void log(String message);
    public void log(Exception exception, String msg);
    public void log(String message, Throwable throwable);
    public void log(String message, int verbosity);
    public void log(String message, Throwable throwable, int verbosity);
    public void removePropertyChangeListener(PropertyChangeListener listener);
}

Tomcat的日志记录器

LoggerBase类(抽象类)

public void log(String message, int verbosity) {
    if (this.verbosity >= verbosity)
        log(message);
}
public void log(String message, Throwable throwable, int verbosity) {
    if (this.verbosity >= verbosity)
        log(message, throwable);
}

SystemOutLogger类

SysteErrLogger类

FileLogger类

public void log(String msg) {

        // Construct the timestamp we will use, if requested
        Timestamp ts = new Timestamp(System.currentTimeMillis());
        String tsString = ts.toString().substring(0, 19);
        String tsDate = tsString.substring(0, 10);
        System.out.println("tsString   "+tsString); //tsString   2014-10-20 15:25:27
        System.out.println("ts   "+ts);            //ts   2014-10-20 15:25:27.406
        System.out.println("tsDate   "+tsDate);        //tsDate   2014-10-20

        // If the date has changed, switch log files
        if (!date.equals(tsDate)) {
            synchronized (this) {
                if (!date.equals(tsDate)) {
                    close();
                    date = tsDate;
                    open();
                }
            }
        }

        // Log this message, timestamped if necessary
        if (writer != null) {
            if (timestamp) {
                writer.println(tsString + " " + msg);
            } else {
                writer.println(msg);
            }
        }
    }

   private void open() {

        // Create the directory if necessary
        File dir = new File(directory);
        if (!dir.isAbsolute())
            dir = new File(System.getProperty("catalina.base"), directory);  //至于catalina.base是什么 一会再说
        dir.mkdirs();

        // Open the current log file
        try {
            String pathname = dir.getAbsolutePath() + File.separator +
                prefix + date + suffix;
            writer = new PrintWriter(new FileWriter(pathname, true), true);
        } catch (IOException e) {
            writer = null;
        }

    }

    private void close() {

        if (writer == null)
            return;
        writer.flush();
        writer.close();
        writer = null;
        date = "";
    }

应用程序

Bootstrap类

...
    System.setProperty("catalina.base", System.getProperty("user.dir"));
    FileLogger logger = new FileLogger();
    logger.setPrefix("FileLog_");
    logger.setSuffix(".txt");
    logger.setTimestamp(true);
    logger.setDirectory("webroot");
    context.setLogger(logger);
....

SimpleContext类

public synchronized void start() throws LifecycleException {
    log("starting Context");
    ........
    lifecycle.fireLifecycleEvent(AFTER_START_EVENT, null);
    log("Context started");
  }
private void log(String message) {
    Logger logger = this.getLogger();
    if (logger!=null)
      logger.log(message);
  }

how tomcat works 七 日志记录器

标签：tomcat   读书笔记   日志记录器   timestamp   

原文地址：http://blog.csdn.net/dlf123321/article/details/40301619