cc.pp.analyzer.paoding.dictionary.support.detection.Detector.java Source code

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Here is the source code for cc.pp.analyzer.paoding.dictionary.support.detection.Detector.java

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/**
 * Copyright 2007 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package cc.pp.analyzer.paoding.dictionary.support.detection;

import java.io.File;
import java.io.FileFilter;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

/**
 * 
 * @author Zhiliang Wang [qieqie.wang@gmail.com]
 * 
 * @since 2.0.2
 * 
 */
public class Detector implements Runnable {

    private Log log = LogFactory.getLog(this.getClass());

    private DifferenceListener listener;

    private File home;

    private FileFilter filter;

    private long interval;

    private Snapshot lastSnapshot;

    private Thread thread;

    private boolean alive = true;

    public void setListener(DifferenceListener listener) {
        this.listener = listener;
    }

    public Detector() {
    }

    /**
     * 
     * 
     * @param interval
     */
    public void setInterval(int interval) {
        this.interval = interval * 1000;
    }

    public void setHome(File home) {
        this.home = home;
    }

    public void setHome(String home) {
        this.home = new File(home);
    }

    public void setFilter(FileFilter filter) {
        this.filter = filter;
    }

    public Snapshot flash() {
        return Snapshot.flash(home, filter);
    }

    public void start(boolean daemon) {
        if (lastSnapshot == null) {
            lastSnapshot = flash();
        }
        thread = new Thread(this);
        thread.setDaemon(daemon);
        thread.start();
    }

    public Snapshot getLastSnapshot() {
        return lastSnapshot;
    }

    public void setLastSnapshot(Snapshot last) {
        this.lastSnapshot = last;
    }

    public void run() {
        if (interval <= 0)
            throw new IllegalArgumentException("should set a interval(>0) for the detection.");
        while (alive) {
            sleep();
            forceDetecting();
        }
    }

    public void forceDetecting() {
        Snapshot current = flash();
        Difference diff = current.diff(lastSnapshot);
        if (!diff.isEmpty()) {
            try {
                listener.on(diff);
                log.info("found differen for " + home);
                log.info(diff);
                lastSnapshot = current;
            } catch (Exception e) {
                log.error("", e);
            }
        }
    }

    public void setStop() {
        alive = false;
        thread = null;
    }

    private void sleep() {
        try {
            Thread.sleep(interval);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
    }

    public static void main(String[] args) {
        Detector d = new Detector();
        d.setInterval(1);
        d.setHome(new File("dic"));
        d.setFilter(new ExtensionFileFilter(".dic"));
        d.setListener(new DifferenceListener() {
            public void on(Difference diff) {
                System.out.println(diff);
            }

        });
        d.start(false);
    }

}