abstractsessionfilterchain.java

银行项目为后台ｓｏｃｋｅｔ通信写的程序

/****************************************************************************
 * Package		: com.ecSolutions.ecAppServer.server.session
 * File			: AbstractSessionFilterChain.java
 * Create Date  : 2007-7-20
 * Author		: Steven Chen
 * 
 * Copyright(C) 2006 ecSolutions(shanghai) Co.,Limited.All Rights Reserved.
 *			
 ***************************************************************************/
package com.ecSolutions.ecAppServer.server.session;

import com.ecSolutions.ecAppServer.server.Packet;
import com.ecSolutions.ecAppServer.server.SessionFilter;
import com.ecSolutions.ecAppServer.server.SessionFilterChain;
import com.ecSolutions.ecAppServer.server.filter.NullFilter;

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

/**
 * Abstract session filter chain.
 * 
 * @author Steven Chen
 * @version $Id: AbstractSessionFilterChain.java,v 1.2 2007/07/26 03:33:50 stevenchen Exp $
 */
public abstract class AbstractSessionFilterChain implements SessionFilterChain {

    private static final Log log = LogFactory
            .getLog(AbstractSessionFilterChain.class);

    /**
     * Null-Object pattern.
     */
    private static final SessionFilter NULL_FILTER = new NullFilter();

    protected abstract SessionFilter nextFilter();

    private void caughtException(Throwable throwable) {
        getSession().getSessionFilterChain(false).exceptionCaught(throwable);
    }

    private SessionFilter next() {
        SessionFilter filter = nextFilter();
        return filter == null ? NULL_FILTER : filter;
    }

    public void exceptionCaught(Throwable cause) {
        try {
            next().exceptionCaught(this, cause);
        } catch (Throwable e) { // protect catch
            log.error(e, e);
        }
    }

    public void packetReceived(Packet packet) {
        try {
            next().packetReceived(this, packet);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

    public void objectReceived(Object obj) {
        try {
            next().objectReceived(this, obj);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

    public void packetSend(Packet packet) {
        try {
            next().packetSend(this, packet);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

    public void packetSent(Packet packet) {
        try {
            next().packetSent(this, packet);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

    public void objectSent(Object obj) {
        try {
            next().objectSent(this, obj);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

    public void sessionClosed() {
        try {
            next().sessionClosed(this);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

    public void sessionStarted() {
        try {
            next().sessionStarted(this);
        } catch (Throwable e) {
            caughtException(e);
        }

    }

    public void sessionTimeout() {
        try {
            next().sessionTimeout(this);
        } catch (Throwable e) {
            caughtException(e);
        }
    }

}