//客户端代码
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.net.InetAddress;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.util.Scanner;


public class SendFileClient
{

    
 
    public static void main( String[] args ) throws IOException
    {
        // TODO Auto-generated method stub

        System.out.println( "This is client" );
        byte[] buf = new byte[1024];

        System.out.println("Please input the Ip Address that you connect");
		//Create the scanner s1 to let user input the server IP address
        Scanner s1 = new Scanner(System.in);
        String ip = s1.nextLine();
        System.out.println("Please input the port");
		//Create the scanner s2 to let user input the server port
        Scanner s2 = new Scanner(System.in);
        String portStr = s2.nextLine();
		//Convert the String portStr to integer
        int port = Integer.parseInt(portStr);

        try
        {
            // Create the socket
            Socket s = new Socket();
            s.connect ( new InetSocketAddress (ip,port ));
			//Create the outstream
            OutputStream os = s.getOutputStream( );
			//Create the inputstream
            InputStream is = s.getInputStream( );
			//Read the buf though the inputstream
            int len = is.read( buf );
			//Print out the data by converting it to a String
            System.out.println( new String( buf, 0, len ) );
            System.out.println("Please input the request");
			//Create scanner s3 to Let the user input the request
			//The request format has to be:Send filename
            Scanner s3 = new Scanner(System.in);
            String req = s3.nextLine();
            os.write( req.getBytes( ) );
			//Read the data to buf though the inputstream
            int len2 = is.read(buf);
            String file = new String(buf,0,len2);
            System.out.println("Wait...");
			//Create the dataoutputstream for receiving the file
           DataOutputStream fos = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(file)));
            byte[] buff = new byte[1024];
			//Receive the file, write it out.
            int data;
            while ( -1 != ( data = is.read(buff) ) )
            {
                fos.write( buff );
            }
            
     
            
           
            System.out.println("\nFile has been received successfully.");
			fos.flush();
			fos.close();
			//Close the outputstream
			os.flush();
            os.close();
			//Close the inputstream
            is.close();
			//Close the socket
            s.close( );
        } catch ( Exception ex )
        {
            ex.printStackTrace();
        }
    }
    

}

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

//服务器端代码
public class SendFileSocket extends Thread
{
    /**
     * @param args
     */
    public static void main( String[] args )
    {
	//Start the server
        server( );

    }
	//Set the Server port =10000
    private static final int  PORT  = 10000;
    private Socket  s;

    public SendFileSocket( Socket s )
    {
	//Create the socket object
        this.s = s;
    }

    public void run()
    {
        try
        {
		//Create the outputstream
            OutputStream os = s.getOutputStream( );
			//Create the inputstream
            InputStream is = s.getInputStream( );
            os.write( "Hello,welcome you!".getBytes( ) );
			//Define the data byte as buf
            byte[] buf = new byte[10240];
            while ( true )
            {
				//Read the buf though the inputstream
                int len = is.read( buf );
                String revStr = new String( buf, 0, len );
				//Print out the request information from the client
                System.out.println( "This client wants to "+revStr );
                String fileName;
				//The requet should starts with Send
                if ( revStr.startsWith( "Send " ))

                {
					//Get the file name from the request by using
					//The method getFileName
                    fileName = getFileName( revStr );
					//Print out the filename
                    System.out.println( "The file name is :"+fileName);
					//Write out the filename though the outputstream 
                    os.write(fileName.getBytes());
                    System.out.println("Start to send file " +fileName);
                    String filePath = "C:/";
                    String file = (filePath+fileName);
					//Combine the filepath and the filename
                    File fi = new File(file);
                   //Declare a datainputstream
				   DataInputStream fins = new DataInputStream(
                        new BufferedInputStream(new FileInputStream(file)));
                    DataOutputStream ps = new DataOutputStream(s.getOutputStream());
					//Start to read the data from the file
                    byte[] buff = new byte[10240];
                    int data;
                    while ( -1 != ( data = fins.read(buff) ) )
                        {
                            //send the file data to the client
                            ps.write( buff );
							
                        }
                        System.out.println("Transfer complete.");
						ps.flush();
						ps.close();
                        break;
						
                 }
                  	else{

                  		System.out.println("Request is wrong");
                  		System.exit(0);


                  	}

            }
			
			
			os.flush();
			//Close the outputstream
            os.close( );
			//Close the inputstream
            is.close( );
			//Close the socket
            s.close( );
        } catch ( Exception e )
        {
		//Catch the exception
            e.printStackTrace( );
        }

    }

    /* 
     * Function：Get the filename from the request which is sent from the client
     * param：The request from the client has to start with"Send"
     * Return: The filename
     */
    private String getFileName( String revStr )
    {
        String fileName;
        fileName = revStr.substring( 4 );
        while ( fileName.startsWith( " " ) )
        {
            fileName = fileName.substring( 1 );
        }
        return fileName;
    }

    public static void server()
    {
        System.out.println( "This is server" );
        try
        {
            ServerSocket ss = new ServerSocket( PORT );
            int count = 0;
            while ( true )
            {
				//Create a socket for waiting for the client connect
                Socket s = ss.accept( );
				//Count the client and print out
                count++ ;
                System.out.println( "This is the " + count + "'st client connetion!" );
				//Start new thread for this socket
                new Thread(new SendFileSocket(s)).start();

            }
        } catch ( Exception ex )
		//Catch the exception
        {
            ex.printStackTrace( );
        }
    }


}