dbnotifier.java

来自「短信发送」· Java 代码 · 共 71 行

/**
 * Created at Nov 25, 2008
 */
package com.jdev.app.db.event;

import java.util.ArrayList;

import com.jdev.net.queue.Request;
import com.jdev.net.queue.Response;

/**
 * <p>Title: DbNotifier</p>
 * <p>Description: </p>
 * @author Lawrence
 * @version 
 */
public class DbNotifier {

    private static ArrayList<DbServerListener> listeners = null;
    private static DbNotifier instance = null;

    private DbNotifier() {
        listeners = new ArrayList<DbServerListener>();
    }

    /**
     * 获取事件触发器
     * @return 返回事件触发器
     */
    public static synchronized DbNotifier getNotifier() {
        if (instance == null) {
            instance = new DbNotifier();
            return instance;
        }
        else return instance;
    }

    /**
     * 添加事件监听器
     * @param l 监听器
     */
    public void addListener(DbServerListener l) {
        synchronized (listeners) {
            if (!listeners.contains(l))
                listeners.add(l);
        }
    }

    public void fireOnRead(DbRequest request) throws Exception {
        for (int i = listeners.size() - 1; i >= 0; i--)
            ( (DbServerListener) listeners.get(i)).onRead(request);

    }

    public void fireOnWrite(DbRequest request)  throws Exception  {
        for (int i = listeners.size() - 1; i >= 0; i--)
            ( (DbServerListener) listeners.get(i)).onWrite(request);

    }

    public void fireOnError(String error) {
        for (int i = listeners.size() - 1; i >= 0; i--)
            ( (DbServerListener) listeners.get(i)).onError(error);
    }

    public void fireOnConnected() throws Exception {
        for (int i = listeners.size() - 1; i >= 0; i--)
            ( (DbServerListener) listeners.get(i)).onConnected();
    }
}