import java.io.*;
import java.util.*;
import java.net.*; 

public class receiveServer {
    final int RECEIVE_PORT=9090;
    
    public receiveServer() {
        ServerSocket rServer=null;
        
        Socket request=null;
        
        Thread receiveThread=null;
        try{
            rServer=new ServerSocket(RECEIVE_PORT);
            rServer.setSoTimeout(0);
            
            while(true){ 

                System.out.println("等待用户请求.");
                request=rServer.accept(); 
                System.out.println("接收客户机连接请求.");
                
                receiveThread=new serverThread(request);
                
                receiveThread.start();
                
            }
        }catch(IOException e){
            e.printStackTrace();
        }
    }
    public static void main(String args[]){ 
        new receiveServer();
    }
}

import java.net.*;
import java.io.*;

public class serverThread extends Thread {
    Socket clientRequest;
    
    InputStreamReader reader;
    BufferedReader input;
    InputStream inputStream = null;
    
    PrintWriter output;
    OutputStreamWriter writer;
    OutputStream outputStream;
    
    
    public serverThread(Socket s) {
        this.clientRequest=s;
        try{
            outputStream = clientRequest.getOutputStream();
            inputStream = clientRequest.getInputStream();
            reader =  new InputStreamReader(inputStream);
            writer =  new OutputStreamWriter(outputStream);
            input  =  new BufferedReader(reader);
            output =  new PrintWriter(writer,true);
        }catch(IOException e){
            e.printStackTrace();
        }
    }

    public void run(){
        String command=null;
        String str=null;
        boolean done=false;
        while(!done){
            try{
                str=input.readLine();
            }catch(IOException e){
                System.out.println(e.getMessage());
            }
            command=str.trim().toUpperCase();
            if(str==null || command.equals("QUIT"))
                done=true;
            else if(command.equals("HELP")){
                output.println("query");
                output.println("quit");
                output.println("help");
                output.println("sendfile");
            } else if(command.startsWith("QUERY")){
                output.println("query");
            }else if(command.startsWith("SENDFILE")){
                output.println("READY\n");
                output.flush();
                
                try{
                    String savePath = "/home/hwcd/002.xls";

                    DataOutputStream fileOut = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(savePath)));
                    
                    DataInputStream inputS = new DataInputStream(new BufferedInputStream(this.inputStream));
                    System.out.println("文件的长度为:" + inputS.readLong() + "\n");
                    System.out.println("开始接收文件!" + "\n");
                    
                    DataOutputStream outputS = new DataOutputStream(this.outputStream);
                    
                    byte[] buf=new byte[4096];
                    
                    while(true){
                        int num=0;
                        num = inputS.read(buf); //客户端会一直停在这个地方。
                        System.out.println("num="+num+"\n");
                        if (num == -1) {
                            break;
                        }
                        fileOut.write(buf, 0, num);
                    }
                    
                    System.out.println("接收完成:"+clientRequest.isClosed()+ "\n");
                    outputS.writeUTF("OK\n");
                    outputS.flush();
                    
                    done=true;
                    fileOut.close();
                    
                }catch(Exception e){
                    e.printStackTrace();
                    done=true;
                }
            }else if(!command.startsWith("HELP") && !command.startsWith("SENDFILE") && !command.startsWith("QUIT") && !command.startsWith("QUERY")){
                output.println("Command not Found!Please refer to the HELP!"); 
            }
        }
    
        try{
            clientRequest.close();
        }catch(IOException e){
            System.out.println(e.getMessage());
        }
        command=null;
    }
}