source: trunk/CrossPare/src/de/ugoe/cs/cpdp/decentApp/FileWatcher.java @ 40

package de.ugoe.cs.cpdp.decentApp;

import java.util.*;
import java.io.*;

/**
 * Helper class for watching if a file was changed
 * 
 * @author Philip Makedonski
 *
 */
public abstract class FileWatcher extends TimerTask {
        // Last timestamp
        private long timeStamp;
        
        // File to watch
        private File file;

        /**
         * Constructor
         * @param file
         */
        public FileWatcher(File file) {
                this.file = file;
                this.timeStamp = file.lastModified();
        }

        /**
         * Watches a file and executes the onChange Method
         * if a file is changed
         */
        public final void run() {
                long timeStamp = file.lastModified();

                if (this.timeStamp != timeStamp) {
                        this.timeStamp = timeStamp;
                        onChange(file);
                }
        }

        protected abstract void onChange(File file);
}