com.voa.weixin.handler.HandlerManager.java Source code

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Here is the source code for com.voa.weixin.handler.HandlerManager.java

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/**
 This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
    
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.
    
You should have received a copy of the GNU General Public License
along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package com.voa.weixin.handler;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.dom4j.Document;
import org.dom4j.Element;

import com.voa.weixin.message.MessageType;
import com.voa.weixin.utils.LogUtil;
import com.voa.weixin.utils.WeixinUtils;

/**
 * ??
 * @author zhaiyuxin
 *
 */
public class HandlerManager {

    private static final Log logger = LogFactory.getLog(HandlerManager.class);

    /**
     * String?? List<String>:handler??
     */
    private Map<String, List<String>> chains;

    private static HandlerManager manager;

    private HandlerManager() {
        init();
    }

    private void init() {
        chains = new HashMap<String, List<String>>();

        chains.put(MessageType.HANDLER_TYPE_TEXT, new ArrayList<String>());
        chains.put(MessageType.HANDLER_TYPE_IMAGE, new ArrayList<String>());
        chains.put(MessageType.HANDLER_TYPE_VOICE, new ArrayList<String>());
        chains.put(MessageType.HANDLER_TYPE_VIDEO, new ArrayList<String>());
        chains.put(MessageType.HANDLER_TYPE_LOCATION, new ArrayList<String>());
        chains.put(MessageType.HANDLER_TYPE_LINK, new ArrayList<String>());

        chains.put(MessageType.HANDLER_EVENT_SUBSCRIBE, new ArrayList<String>());
        chains.put(MessageType.HANDLER_EVENT_SUBSCRIBE_QRSCENE, new ArrayList<String>());
        chains.put(MessageType.HANDLER_EVENT_UNSUBSCRIBE, new ArrayList<String>());
        chains.put(MessageType.HANDLER_EVENT_SCAN, new ArrayList<String>());
        chains.put(MessageType.HANDLER_EVENT_LOCATION, new ArrayList<String>());
        chains.put(MessageType.HANDLER_EVENT_CLICK, new ArrayList<String>());

        Document doc = null;
        try {
            doc = WeixinUtils.getDocumentResource("weixin.handler.xml");
        } catch (Exception e) {
            logger.error("weixin.handler.xml parser error");
            e.printStackTrace();
            return;
        }

        Element root = doc.getRootElement();
        logger.debug(root.asXML());
        List<Element> handlerEs = root.elements();
        for (Element handlerE : handlerEs) {
            String handlerName = handlerE.elementText("name");
            logger.debug("handlerName : " + handlerName);
            List<Element> handlerClzEs = handlerE.elements("handlerclz");
            if (handlerClzEs == null || handlerClzEs.size() == 0)
                continue;

            List<String> handlerClzNames = chains.get(handlerName);
            logger.debug("handlerClzNames:" + handlerClzNames);
            if (handlerClzNames == null)
                continue;
            for (Element handlerClzE : handlerClzEs) {
                String clzName = handlerClzE.getText();
                try {
                    Class.forName(clzName);
                    handlerClzNames.add(clzName);
                } catch (ClassNotFoundException e) {
                    logger.error(clzName + " class not fount exception");
                    e.printStackTrace();
                }
            }
        }

    }

    public static HandlerManager getInstance() {
        if (manager == null)
            manager = new HandlerManager();

        return manager;
    }

    public HandlerChain getChain(String handlerType) {
        List<String> clzNames = chains.get(handlerType);
        logger.debug("handlerType = " + handlerType);
        if (clzNames == null)
            return null;
        logger.debug("clzNames = " + clzNames);
        HandlerChain chain = new HandlerChain(handlerType);

        try {
            for (String clzName : clzNames) {
                Class clz = Class.forName(clzName);
                Handler handler = (Handler) clz.newInstance();
                chain.append(handler);
            }

            return chain;
        } catch (Exception e) {
            e.printStackTrace(LogUtil.getErrorStream(logger));
            e.printStackTrace();
        }

        return null;
    }
}