您如何将发送到服务器的同一映像下载回客户端？

Question

我有两个项目；一个用于我的服务器，另一个用于我的客户端，我能够轻松地将图像发送到服务器。但是我想知道，当我按下在客户端GUI上创建的下载按钮时，如何将刚刚发送到服务器的映像重新下载回客户端？我的代码是用Java编写的。

非常感谢

这是我的服务器处理程序

    String fileName;
        fileName = "RecievedImageoutreach1.jpg";
        DataOutputStream dout = new DataOutputStream(sock.getOutputStream());

//Coding for image transfer 
        int flag=0,i; 
        String extn=""; 
            for(i=0; i<fileName.length(); i++) 
            { 
                if(fileName.charAt(i)=='.' || flag==1) 
                { 
                flag=1; 
                extn += fileName.charAt(i); 
                } 
            }

            if(extn.equals(".jpg") || extn.equals(".gif")) 
                {
                try{

                    File file = new File(fileName); 
                    FileInputStream fin = new FileInputStream(file);    
                    dout.writeUTF(fileName);  
                    byte[] readData = new byte[1024];

                    while((i = fin.read(readData)) != -1) 
                            { 
                            dout.write(readData, 0, i); 
                            }  
                            //ta.appendText("\nImage Has Been Sent");

                            dout.flush();
                            fin.close(); 
                    }catch(IOException ex)
                      {System.out.println("Image ::"+ex);}

                }

    }

这是我的客户

   public void download() throws IOException {
    // Get input from the server

    DataInputStream dis = new DataInputStream (sock.getInputStream()); 
    String str,extn = ""; 
    str = dis.readUTF();

    int flag=0,i;

        for(i=0;i<str.length();i++) 
        {

            if(str.charAt(i)=='.' || flag==1) 
            { 
            flag=1; 
            extn+=str.charAt(i); 
            }
        }

// ***阅读图片*** * //

       if(extn.equals(".jpg") || extn.equals(".gif")) 
          {             
            File file = new File("Downloaded"+str); 
            FileOutputStream fout = new FileOutputStream(file);

            //receive and save image from client 
            byte[] readData = new byte[1024]; 
            while((i = dis.read(readData)) != -1) 
            {
                fout.write(readData, 0, i); 
                if(flag==1) 
                { 
                ta.append("Image Has Been Downloaded"); 
                flag=0; 
                } 
            } 
        fout.flush(); 
        fout.close();

          } 
}

但是运行时什么也没发生？我已经链接了单击按钮时要运行的客户端方法。

Answer 1

我会做这样的事情：

//服务器处理程序

 File file = new File(fileName); 
 FileInputStream fin = new FileInputStream(file);    
// dout.writeUTF(fileName); 
   byte[] readData = new byte[1024]; 
   fin.read(readData);  
   fin.close();
   dout.write(readData, 0, readData.length); 
   dout.flush();

  /* while((i = fin.read(readData)) != -1) 
   { 
       dout.write(readData, 0, i); 
   }*/  
                        //ta.appendText("\nImage Has Been Sent");

                        dout.flush();
                        fin.close(); 
                }catch(IOException ex)
                  {System.out.println("Image ::"+ex);}

            }

//接收图片

if(extn.equals(".jpg") || extn.equals(".gif")) 
      {   
        //give path to new file
        File file = new File(".//Downloaded"+str); 
        FileOutputStream fout = new FileOutputStream(file);

        //receive and save image from client 
        byte[] readData = new byte[1024]; 
        int offset =0; 
        while((i = dis.read(readData,0,readData.length-offset)) != -1){
              offset += i;
        }

            fout.write(readData, 0, readData.length); 
            if(flag==1) 
            { 
            ta.append("Image Has Been Downloaded"); 
            flag=0; 
            }

    fout.flush(); 
    fout.close();

      } 
}