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JAVA實(shí)現(xiàn)長連接(含心跳檢測Demo)

更新時(shí)間：2019年10月11日 11:34:16 作者：零度anngle

這篇文章主要介紹了JAVA實(shí)現(xiàn)長連接(含心跳檢測Demo),文中通過示例代碼介紹的非常詳細(xì)，對(duì)大家的學(xué)習(xí)或者工作具有一定的參考學(xué)習(xí)價(jià)值，需要的朋友們下面隨著小編來一起學(xué)習(xí)學(xué)習(xí)吧

實(shí)現(xiàn)原理：
長連接的維持，是要客戶端程序，定時(shí)向服務(wù)端程序，發(fā)送一個(gè)維持連接包的。
如果，長時(shí)間未發(fā)送維持連接包，服務(wù)端程序?qū)嚅_連接。

客戶端：
       Client通過持有Socket的對(duì)象，可以隨時(shí)（使用sendObject方法）發(fā)送Massage Object(消息)給服務(wù)端。
       如果keepAliveDelay毫秒（程序中是2秒）內(nèi)未發(fā)送任何數(shù)據(jù)，則自動(dòng)發(fā)送一個(gè)KeepAlive Object(心跳)給服務(wù)端，用于維持連接。
       由于，我們向服務(wù)端，可以發(fā)送很多不同的消息對(duì)象，服務(wù)端也可以返回不同的對(duì)象。所以，對(duì)于返回對(duì)象的處理，要編寫具體的ObjectAction實(shí)現(xiàn)類進(jìn)行處理。通過Client.addActionMap方法進(jìn)行添加。這樣，程序會(huì)回調(diào)處理。

服務(wù)端：
        由于客戶端會(huì)定時(shí)（keepAliveDelay毫秒）發(fā)送維持連接的信息過來，所以，服務(wù)端要有一個(gè)檢測機(jī)制。
        即當(dāng)服務(wù)端receiveTimeDelay毫秒（程序中是3秒）內(nèi)未接收任何數(shù)據(jù)，則自動(dòng)斷開與客戶端的連接。
         ActionMapping的原理與客戶端相似（相同）。

通過添加相應(yīng)的ObjectAction實(shí)現(xiàn)類，可以實(shí)現(xiàn)不同對(duì)象的響應(yīng)、應(yīng)答過程。

Demo:

package socket.keepalive.test;
 
 
import java.io.Serializable;
import java.text.SimpleDateFormat;
import java.util.Date;
 
/**
 * 
 * 維持連接的消息對(duì)象（心跳對(duì)象）
 */
public class KeepAlive implements Serializable{
 
 private static final long serialVersionUID = -2813120366138988480L;
 
 /* 覆蓋該方法，僅用于測試使用。
 * @see java.lang.Object#toString()
 */
 @Override
 public String toString() {
 return new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(new Date())+"\t維持連接包";
 }
 
}

package socket.keepalive.test;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.Socket;
import java.net.UnknownHostException;
import java.util.Collections;
import java.util.concurrent.ConcurrentHashMap;
 
/**
 * C/S架構(gòu)的客戶端對(duì)象，持有該對(duì)象，可以隨時(shí)向服務(wù)端發(fā)送消息。
 * <p>
 * 創(chuàng)建時(shí)間：2010-7-18 上午12:17:25
 * @author HouLei
 * @since 1.0
 */
public class Client {
 
 /**
 * 處理服務(wù)端發(fā)回的對(duì)象，可實(shí)現(xiàn)該接口。
 */
 public static interface ObjectAction{
 void doAction(Object obj,Client client);
 }
 
 public static final class DefaultObjectAction implements ObjectAction{
 public void doAction(Object obj,Client client) {
  System.out.println("處理：\t"+obj.toString());
 }
 }
 
 
 public static void main(String[] args) throws UnknownHostException, IOException {
 String serverIp = "127.0.0.1";
 int port = 65432;
 Client client = new Client(serverIp,port);
 client.start();
 }
 
 private String serverIp;
 private int port;
 private Socket socket;
 private boolean running=false; //連接狀態(tài)
 
 private long lastSendTime; //最后一次發(fā)送數(shù)據(jù)的時(shí)間
 
 //用于保存接收消息對(duì)象類型及該類型消息處理的對(duì)象
 private ConcurrentHashMap<Class, ObjectAction> actionMapping = new ConcurrentHashMap<Class,ObjectAction>();
 
 public Client(String serverIp, int port) {
 this.serverIp=serverIp;
 this.port=port;
 }
 
 public void start() throws UnknownHostException, IOException {
 if(running)return;
 socket = new Socket(serverIp,port);
 System.out.println("本地端口："+socket.getLocalPort());
 lastSendTime=System.currentTimeMillis();
 running=true;
 new Thread(new KeepAliveWatchDog()).start(); //保持長連接的線程，每隔2秒項(xiàng)服務(wù)器發(fā)一個(gè)一個(gè)保持連接的心跳消息
 new Thread(new ReceiveWatchDog()).start();  //接受消息的線程，處理消息
 }
 
 public void stop(){
 if(running)running=false;
 }
 
 /**
 * 添加接收對(duì)象的處理對(duì)象。
 * @param cls 待處理的對(duì)象，其所屬的類。
 * @param action 處理過程對(duì)象。
 */
 public void addActionMap(Class<Object> cls,ObjectAction action){
 actionMapping.put(cls, action);
 }
 
 public void sendObject(Object obj) throws IOException {
 ObjectOutputStream oos = new ObjectOutputStream(socket.getOutputStream());
 oos.writeObject(obj);
 System.out.println("發(fā)送：\t"+obj);
 oos.flush();
 }
 
 class KeepAliveWatchDog implements Runnable{
 long checkDelay = 10;
 long keepAliveDelay = 2000;
 public void run() {
  while(running){
  if(System.currentTimeMillis()-lastSendTime>keepAliveDelay){
   try {
   Client.this.sendObject(new KeepAlive());
   } catch (IOException e) {
   e.printStackTrace();
   Client.this.stop();
   }
   lastSendTime = System.currentTimeMillis();
  }else{
   try {
   Thread.sleep(checkDelay);
   } catch (InterruptedException e) {
   e.printStackTrace();
   Client.this.stop();
   }
  }
  }
 }
 }
 
 class ReceiveWatchDog implements Runnable{
 public void run() {
  while(running){
  try {
   InputStream in = socket.getInputStream();
   if(in.available()>0){
   ObjectInputStream ois = new ObjectInputStream(in);
   Object obj = ois.readObject();
   System.out.println("接收：\t"+obj);
   ObjectAction oa = actionMapping.get(obj.getClass());
   oa = oa==null?new DefaultObjectAction():oa;
   oa.doAction(obj, Client.this);
   }else{
   Thread.sleep(10);
   }
  } catch (Exception e) {
   e.printStackTrace();
   Client.this.stop();
  } 
  }
 }
 }
 
}

package socket.keepalive.test;
 
import java.io.IOException;
import java.io.InputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.concurrent.ConcurrentHashMap;
 
/**
 * C/S架構(gòu)的服務(wù)端對(duì)象。
 * <p>
 * 創(chuàng)建時(shí)間：2010-7-18 上午12:17:37
 * @author HouLei
 * @since 1.0
 */
public class Server {
 
 /**
 * 要處理客戶端發(fā)來的對(duì)象，并返回一個(gè)對(duì)象，可實(shí)現(xiàn)該接口。
 */
 public interface ObjectAction{
 Object doAction(Object rev, Server server);
 }
 
 public static final class DefaultObjectAction implements ObjectAction{
 public Object doAction(Object rev,Server server) {
  System.out.println("處理并返回："+rev);
  return rev;
 }
 }
 
 public static void main(String[] args) {
 int port = 65432;
 Server server = new Server(port);
 server.start();
 }
 
 private int port;
 private volatile boolean running=false;
 private long receiveTimeDelay=3000;
 private ConcurrentHashMap<Class, ObjectAction> actionMapping = new ConcurrentHashMap<Class,ObjectAction>();
 private Thread connWatchDog;
 
 public Server(int port) {
 this.port = port;
 }
 
 public void start(){
 if(running)return;
 running=true;
 connWatchDog = new Thread(new ConnWatchDog());
 connWatchDog.start();
 }
 
 @SuppressWarnings("deprecation")
 public void stop(){
 if(running)running=false;
 if(connWatchDog!=null)connWatchDog.stop();
 }
 
 public void addActionMap(Class<Object> cls,ObjectAction action){
 actionMapping.put(cls, action);
 }
 
 class ConnWatchDog implements Runnable{
 public void run(){
  try {
  ServerSocket ss = new ServerSocket(port,5);
  while(running){
   Socket s = ss.accept();
   new Thread(new SocketAction(s)).start();
  }
  } catch (IOException e) {
  e.printStackTrace();
  Server.this.stop();
  }
  
 }
 }
 
 class SocketAction implements Runnable{
 Socket s;
 boolean run=true;
 long lastReceiveTime = System.currentTimeMillis();
 public SocketAction(Socket s) {
  this.s = s;
 }
 public void run() {
  while(running && run){
  if(System.currentTimeMillis()-lastReceiveTime>receiveTimeDelay){
   overThis();
  }else{
   try {
   InputStream in = s.getInputStream();
   if(in.available()>0){
    ObjectInputStream ois = new ObjectInputStream(in);
    Object obj = ois.readObject();
    lastReceiveTime = System.currentTimeMillis();
    System.out.println("接收：\t"+obj);
    ObjectAction oa = actionMapping.get(obj.getClass());
    oa = oa==null?new DefaultObjectAction():oa;
    Object out = oa.doAction(obj,Server.this);
    if(out!=null){
    ObjectOutputStream oos = new ObjectOutputStream(s.getOutputStream());
    oos.writeObject(out);
    oos.flush();
    }
   }else{
    Thread.sleep(10);
   }
   } catch (Exception e) {
   e.printStackTrace();
   overThis();
   } 
  }
  }
 }
 
 private void overThis() {
  if(run)run=false;
  if(s!=null){
  try {
   s.close();
  } catch (IOException e) {
   e.printStackTrace();
  }
  }
  System.out.println("關(guān)閉："+s.getRemoteSocketAddress());
 }
 
 }
 
}

以上就是本文的全部內(nèi)容，希望對(duì)大家的學(xué)習(xí)有所幫助，也希望大家多多支持腳本之家。

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