通过套接字从客户端发送缓冲图像到服务器

Posted 2023-02-16

【中文标题】通过套接字从客户端发送缓冲图像到服务器

【英文标题】：Sending buffered image over socket from client to server

【发布时间】：2013-07-23 10:24:38

【问题描述】：

我正在尝试将从客户端捕获的图像发送到服务器，使用机器人类捕获图像并写入客户端套接字。在服务器中，我正在读取缓冲图像并写入服务器本地存储区域。我希望客户端定期捕获屏幕截图并发送到服务器。服务器读取图像并存储在其存储库中。

public class ServerDemo 
   public static void main(String[] args) 
     try 

        ServerSocket serversocket=new ServerSocket(6666);
        System.out.println("server listening..........");

        while(true)
        
         Thread ts=new Thread( new ServerThread(serversocket.accept()));
         ts.start();
         System.out.println("server thread started.........");
        
      catch (IOException e) 
       // TODO Auto-generated catch block
       e.printStackTrace();
       

   

 

ServerThread.java

public class ServerThread implements Runnable 
Socket s;
BufferedImage img = null;
String savelocation="d:\\Screenshot\\";

   public ServerThread(Socket server) 
    this.s=server;
   
 @Override
    public void run() 

    try 
        System.out.println("trying to read Image");
        img = ImageIO.read(s.getInputStream());
       System.out.println("Image Reading successful.....");
     catch (IOException e) 
            System.out.println(e);
            // TODO Auto-generated catch block
            e.printStackTrace();
         catch (InterruptedException e) 
            // TODO Auto-generated catch block
            e.printStackTrace();
        
      File save_path=new File(savelocation);
      save_path.mkdirs();
        try 
            ImageIO.write(img, "JPG",new File(savelocation+"img-"+System.currentTimeMillis()+".jpg"));
         System.out.println("Image writing successful......");
         catch (IOException e) 
            // TODO Auto-generated catch block
            System.out.println(e);
            e.printStackTrace();
        
     
    

ClientDemo.java

 public class ClientDemo 
     public static void main(String[] args) throws InterruptedException 
      try 
        Socket client=new Socket("localhost", 6666);
        while(true)
        
            System.out.println("Hello");
            Thread th=new Thread(new ClientThread(client));
            th.start();
            System.out.println("Thread started........");
            th.sleep(1000*60);

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

 

ClientThread.java

 public class ClientThread implements Runnable
 Socket c;
  public ClientThread(Socket client) 
  this.c=client;
  

@Override
public void run() 

    try 
        System.out.println("client");
        //while(true)
        Dimension size=Toolkit.getDefaultToolkit().getScreenSize();
        Robot robot=new Robot();
        BufferedImage img=robot.createScreenCapture(new Rectangle(size));
        System.out.println("Going to capture client screen");

        ImageIO.write(img, "JPG", c.getOutputStream());
        System.out.println("Image capture from client success...!");



     catch (UnknownHostException e) 
        // TODO Auto-generated catch block
        e.printStackTrace();
     catch (IOException e) 
        // TODO Auto-generated catch block
        e.printStackTrace();
     catch (AWTException e) 
        // TODO Auto-generated catch block
        e.printStackTrace();
      

    


   

服务器控制台

服务器监听…………

服务器线程已启动…………

试图读取图像

图片读取成功.....

图像写入成功......

客户端控制台 你好

线程开始......

客户

要捕获客户端屏幕

客户成功的图像捕获...！

你好

线程开始......

客户

要捕获客户端屏幕 你好

线程开始......

客户

要捕获客户端屏幕

像这样重复。此代码在失败后第一次完美运行。每次运行它只捕获一次图像。我必须进行哪些更改才能定期捕获和写入图像...请帮助我

【参考方案1】：

Try this in ClientDemo.java
        while(true)
        
            System.out.println("Hello");
            Socket client=new Socket("localhost", 6666);
            Thread th=new Thread(new ClientThread(client));
            th.start();
            System.out.println("Thread started........");
            th.sleep(1000*60);

        
And make sure that you close the client socket once the thread(ClientThread.java) is completed may be in finally block or at the end of code.

【参考方案2】：

服务器端不需要ImageIO。只需发送和接收字节：

while ((count = in.read(buffer()) > 0)

    out.write(buffer, 0, count);

【参考方案3】：

我发现问题出在服务器上。它第一次接受来自客户端的连接时，

Thread ts=new Thread( new ServerThread(serversocket.accept()));

但是客户端只连接一次

Socket client=new Socket("localhost", 6666);

当第一次传输完成时，服务器再次停留在接受等待客户端进行连接，这永远不会发生再次。因此，您应该只发出一个接受并在每次传输时使用该套接字，或者在客户端和服务器上关闭两个套接字，然后再次进行接受/连接。