androidpn的学习研究（八）androidpn 中业务类XmppIoHandler实现分析

     在androidpn中主要采用Mina进行网络通讯，其中Mina中IoHandler用来处理主要的业务逻辑。

Mina 中源代码如下：

package org.apache.mina.core.service;

import java.io.IOException;

import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.session.IoSession;

/**
 * Handles all I/O events fired by MINA.
 *
 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
 *
 * @see IoHandlerAdapter
 */
public interface IoHandler {
    /**
     * Invoked from an I/O processor thread when a new connection has been created.
     * Because this method is supposed to be called from the same thread that
     * handles I/O of multiple sessions, please implement this method to perform
     * tasks that consumes minimal amount of time such as socket parameter
     * and user-defined session attribute initialization.
     */
    void sessionCreated(IoSession session) throws Exception;

    /**
     * Invoked when a connection has been opened.  This method is invoked after
     * {@link #sessionCreated(IoSession)}.  The biggest difference from
     * {@link #sessionCreated(IoSession)} is that it's invoked from other thread
     * than an I/O processor thread once thread model is configured properly.
     */
    void sessionOpened(IoSession session) throws Exception;

    /**
     * Invoked when a connection is closed.
     */
    void sessionClosed(IoSession session) throws Exception;

    /**
     * Invoked with the related {@link IdleStatus} when a connection becomes idle.
     * This method is not invoked if the transport type is UDP; it's a known bug,
     * and will be fixed in 2.0.
     */
    void sessionIdle(IoSession session, IdleStatus status) throws Exception;

    /**
     * Invoked when any exception is thrown by user {@link IoHandler}
     * implementation or by MINA.  If <code>cause</code> is an instance of
     * {@link IOException}, MINA will close the connection automatically.
     */
    void exceptionCaught(IoSession session, Throwable cause) throws Exception;

    /**
     * Invoked when a message is received.
     */
    void messageReceived(IoSession session, Object message) throws Exception;

    /**
     * Invoked when a message written by {@link IoSession#write(Object)} is
     * sent out.
     */
    void messageSent(IoSession session, Object message) throws Exception;
}

 

Mina中IoHandler可供处理的事件回调

sessionCreate(IoSession)

  IoSession对象被创建时的回调，一般用于进行会话初始化操作。注意：与sessionOpened(IoSession)不同，IoSession对象的创建并不意味着对应底层TCP连接的建立，而仅仅代表字面意思：一个IoSession对象被创建出来了。

sessionOpened(IoSession)

  IoSession对象被打开时回调。在TCP中，该事件是在TCP连接建立时触发，一般可用于发起连接建立的握手、认证等操作。

sessionIdle(IoSession,IdleStatus)

  IoSession对象超时时回调。当一个IoSession对象在指定的超时时常内没有读写事件发生，就会触发该事件，一般可用于通知服务器断开长时间闲置的连接等处理。具体的超时设置可由 IoService.setWriteIdleTime(int) ,IoService.setReadIdleTime(int) ,IoService.setBothIdleTime(int)设置。

messageReceived(IoSession,Object)

  当接收到IoSession对Client发送的数据时回调。

messageSent(IoSession,Object)

  当发送给IoSession对Client的数据发送成功时回调。

exceptionCaught(IoSession,Throwable)

  当会话过程中出现异常时回调，通常用于错误处理。

 

 

 

session.write(Object)方法是一个异步方法，对该方法的调用并不会阻塞，而是向Mina投递一个异步的写操作，并返回一个可用于对已投递异步写操作进行控制的WriteFuture对象。例如：调用WriteFuture的await()或awaitUninterruptibly()，可由同步等待该异步操作的完成。

 

在I/O处理器中实现业务逻辑的时候，对于简单的情况，一般只需要在messageReceived中对传入的消息进行处理。如果需要写回数据到对等体，用IoSession.write()即可。

另外的情况，client和server的通信协议比较复杂，client是有状态变迁的，这时可用Mina提供的状态机实现，可使用IO处理器的实现更加简单。

 

androidpn中XmppIoHandler源代码：

package org.androidpn.server.xmpp.net;

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;

import org.androidpn.server.xmpp.XmppServer;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.mina.core.service.IoHandler;
import org.apache.mina.core.session.IdleStatus;
import org.apache.mina.core.session.IoSession;
import org.dom4j.io.XMPPPacketReader;
import org.jivesoftware.openfire.net.MXParser;
import org.jivesoftware.openfire.nio.XMLLightweightParser;
import org.xmlpull.v1.XmlPullParserException;
import org.xmlpull.v1.XmlPullParserFactory;

/** 
 * This class is to create new sessions, destroy sessions and deliver
 * received XML stanzas to the StanzaHandler.
 *
 * @author Sehwan Noh ([e-mail])
 */
public class XmppIoHandler implements IoHandler {

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

    public static final String XML_PARSER = "XML_PARSER";

    private static final String CONNECTION = "CONNECTION";

    private static final String STANZA_HANDLER = "STANZA_HANDLER";

    private String serverName;

    private static Map<Integer, XMPPPacketReader> parsers = new ConcurrentHashMap<Integer, XMPPPacketReader>();

    private static XmlPullParserFactory factory = null;

    static {
        try {
            factory = XmlPullParserFactory.newInstance(
                    MXParser.class.getName(), null);
            factory.setNamespaceAware(true);
        } catch (XmlPullParserException e) {
            log.error("Error creating a parser factory", e);
        }
    }

    /**
     * Constructor. Set the server name from server instance. 
     */
    protected XmppIoHandler() {
        serverName = XmppServer.getInstance().getServerName();
    }

    /**
     * Invoked from an I/O processor thread when a new connection has been created.
     */
    public void sessionCreated(IoSession session) throws Exception {
        log.debug("sessionCreated()...");
    }

    /**
     * Invoked when a connection has been opened.
     */
    public void sessionOpened(IoSession session) throws Exception {
        log.debug("sessionOpened()...");
        log.debug("remoteAddress=" + session.getRemoteAddress());
        // Create a new XML parser
        XMLLightweightParser parser = new XMLLightweightParser("UTF-8");
        session.setAttribute(XML_PARSER, parser);
        // Create a new connection
        Connection connection = new Connection(session);
        session.setAttribute(CONNECTION, connection);
        session.setAttribute(STANZA_HANDLER, new StanzaHandler(serverName,
                connection));
    }

    /**
     * Invoked when a connection is closed.
     */
    public void sessionClosed(IoSession session) throws Exception {
        log.debug("sessionClosed()...");
        Connection connection = (Connection) session.getAttribute(CONNECTION);
        connection.close();
    }

    /**
     * Invoked with the related IdleStatus when a connection becomes idle.
     */
    public void sessionIdle(IoSession session, IdleStatus status)
            throws Exception {
        log.debug("sessionIdle()...");
        Connection connection = (Connection) session.getAttribute(CONNECTION);
        if (log.isDebugEnabled()) {
            log.debug("Closing connection that has been idle: " + connection);
        }
        connection.close();
    }

    /**
     * Invoked when any exception is thrown.
     */
    public void exceptionCaught(IoSession session, Throwable cause)
            throws Exception {
        log.debug("exceptionCaught()...");
        log.error(cause);
    }

    /**
     * Invoked when a message is received.
     */
    public void messageReceived(IoSession session, Object message)
            throws Exception {
        log.debug("messageReceived()...");
        log.debug("RCVD: " + message);

        // Get the stanza handler
        StanzaHandler handler = (StanzaHandler) session
                .getAttribute(STANZA_HANDLER);

        // Get the XMPP packet parser
        int hashCode = Thread.currentThread().hashCode();
        XMPPPacketReader parser = parsers.get(hashCode);
        if (parser == null) {
            parser = new XMPPPacketReader();
            parser.setXPPFactory(factory);
            parsers.put(hashCode, parser);
        }

        // The stanza handler processes the message
        try {
            handler.process((String) message, parser);
        } catch (Exception e) {
            log.error(
                    "Closing connection due to error while processing message: "
                            + message, e);
            Connection connection = (Connection) session
                    .getAttribute(CONNECTION);
            connection.close();
        }
    }

    /**
     * Invoked when a message written by IoSession.write(Object) is sent out.
     */
    public void messageSent(IoSession session, Object message) throws Exception {
        log.debug("messageSent()...");
    }

}

 XmppIoHandler在加载的时候创建相关的xml解析工厂。

        sessionOpened：在连接打开时候创建相关的xml的解析器和Handler处理器。

        sessionClosed：关闭相关的连接。

        sessionIdle：关闭相关的连接。

        messageReceived：获取相关的xml解析器和handler处理器处理相关的消息。

 

评论

2 楼 yojeajie 2012-10-25  

对于1楼的疑惑一，你可以参考类NotificationPacketListener，这个类是用来监听服务器端发来的数据包（也就是服务器端推送来的消息），在这个类里发送出了一个广播，而NotificationDetailsActivity只是接收这个广播，然后将信息显示出来！！！！[size=large][/size]

1 楼 wenjiefeng 2012-10-13  

你好，在andrioidpn-client客户端源码里，NotificationDetailsActivity这个类里，下面的参数都是什么意思呢
Intent intent = getIntent();
String notificationId = intent
.getStringExtra(Constants.NOTIFICATION_ID);
String notificationApiKey = intent
.getStringExtra(Constants.NOTIFICATION_API_KEY);
String notificationTitle = intent
.getStringExtra(Constants.NOTIFICATION_TITLE);
String notificationMessage = intent
.getStringExtra(Constants.NOTIFICATION_MESSAGE);
String notificationUri = intent
.getStringExtra(Constants.NOTIFICATION_URI);

疑惑1、 这几个参数代表什么意思呢， notificationId; notificationApiKey; notificationTitle; notificationMessage; notificationUri;
我看源码里好几处都用到这几个参数 ，

疑惑2、 现在服务端已经能将消息推送到服务端了并增加了一些参数，推送的消息里增加了距离distance等参数，该在客户端的哪个类里获取这些值呢
我的QQ号是  1297234270

谢谢