见证Android消息推送时刻--笔记---Socket即时通讯机制

        前几天在"慕课网"看到了郭霖大神的视频----点击打开链接"见证Android消息推送时刻",由于自己这段时间也在做即时通讯,作为初级码农,顿时感到与大神如此的接近,所以决定追随大神的步伐,把郭神的每一段代码,每一句话都记下来认真学习,笔记分享给大家,一起学习.1 IM通讯机制研究       长连接  短连接        即时通讯属于长连接,维护一个服务,一直监听消息的到达2 实现在控制台输出内容在服务端接收        ----客户端代码:这个类实现了控制台输出文本              

/**
* 消息推送机制客户端代码
* @author fflin learned by GuoLin
*
*/

public class SocketClient {

public static void main(String[] args) {

/**

* 实现用户在命令行输出消息

*/

SocketClient socketClient = new SocketClient();

socketClient.start();

}

public void start(){

BufferedReader inBufferedReader;

try {

inBufferedReader = new BufferedReader(new InputStreamReader(System.in));

String inputContent;

while(!(inputContent = inBufferedReader.readLine()).equals("bye")){

System.out.println(inputContent);

}

} catch (Exception e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

        ----服务端代码:接收客户端消息   

public class SocketServer {
public static void main(String[] args) {
SocketServer mSocketServer = new SocketServer();
mSocketServer.start();
}
public void start(){
ServerSocket mServerSocket;
BufferedReader reader;
/**
* 创建ServerSocket对象,参数是端口号,
* accept方法表示阻塞服务,等待客户端接入
*/
try {
mServerSocket = new ServerSocket(9998);
Socket mSocket = mServerSocket.accept();
reader = new BufferedReader(new InputStreamReader(mSocket.getInputStream()));
/**
* 客户端发送过来的消息
*/
String receivedMessage;
while((receivedMessage = reader.readLine()) != null){
System.out.println(receivedMessage);
}

} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}

          -----客户端创建Socket消息对象,通过创建输出流,发送消息到服务器        

 //创建服务器的Socket连接,参数:IP地址,端口号socket = new Socket("127.0.0.1",9998);//发送消息writer = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));inBufferedReader = new BufferedReader(new InputStreamReader(System.in));String inputContent;while(!(inputContent = inBufferedReader.readLine()).equals("bye")){writer.write(inputContent+"\n");writer.flush();System.out.println(inputContent);}  

          ----服务端接收到消息,打印到控制台 

 mServerSocket = new ServerSocket(9998);System.out.println("服务启动了....");Socket mSocket = mServerSocket.accept();System.out.println("客户端:"+mSocket.hashCode()+"已经连接服务器");

        -----服务端接收到消息,打印                      -----目前实现了从客户端发送消息给服务端,如果要实现服务端发送消息到客户端,只需要把服务端和客户端的reader和writer替换              ---服务端创建writer对象,回复客户端消息                writer = new BufferedWriter(new OutputStreamWriter(mSocket.getOutputStream()));              ---客户端创建reader,接收服务端消息            reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));3 问题:        目前虽然实现了客户端与服务端的长连接,可是客户端不能被动接受服务端的消息,只能主动发送消息到服务器,才会收到服务器返回的消息       4 完善优化Socket消息机制        ---客户端开启服务器消息监听器,目前客户端已经拥有了随时接受服务端返回消息的能力            public void startServerReplyListener(final BufferedReader reader){        //请求网络等耗时操作要放在子线程中运行        new Thread(new Runnable() {                        @Override            public void run() {                try {                    String response;                        //相当于子线程阻塞,一直监听服务器的消息到达                    while((response = reader.readLine()) != null){                        System.out.println(response);                    }                } catch (IOException e) {                    e.printStackTrace();                }                            }        }).start();    }        -----定时任务                        -----注意一个问题,在读取数据的操作中,程序判断以"\n"(换行符)为一段文本的结束        5 服务端目前存在的问题:只允许一个客户端接入            public void manageConnection(Socket socket){        //为每个建立连接的Socket建立一个线程,进行管理        new Thread(new Runnable() {                        @Override            public void run() {                try {                    reader = new BufferedReader(new InputStreamReader(mSocket.getInputStream()));                    writer = new BufferedWriter(new OutputStreamWriter(mSocket.getOutputStream()));                        /**                     * 客户端发送过来的消息                     */                    String receivedMessage;                    while((receivedMessage = reader.readLine()) != null){                        System.out.println(receivedMessage);                        //服务器收到消息,回复给客户端,注意加换行符                        writer.write("服务端收到消息,回复:"+receivedMessage+"\n");                        writer.flush();                    }                } catch (IOException e) {                    // TODO Auto-generated catch block                    e.printStackTrace();                }finally{                    try {                        reader.close();                        writer.close();                    } catch (IOException e) {                        // TODO Auto-generated catch block                        e.printStackTrace();                    }                }                            }        }).start();            -----调用管理客户端接入的方法                    while (true) {                 mSocket = mServerSocket.accept();                    manageConnection(mSocket);                System.out.println("客户端:" + mSocket.hashCode() + "已经连接服务器");            }       ----运行效果