modifiedclient.java

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

 /**
  * A client program which can send a request to server
  * @author yaoyiyang
  *
  */
 public class ModifiedClient {
	 
	 private static BufferedReader  stdIn =
		 new  BufferedReader(new  InputStreamReader(System.in));
	 
	 /**
	  * the main body of the program
	  * @param argv the hostname
	  * @throws Exception
	  */
	 public static void main(String argv[]) throws Exception { 
		 
		 /*some strings to be used*/
		 String command;
		 String request;
		 String result;
		 int flag = 0;
		 Socket clientSocket = null;
		 DataOutputStream outToServer = null;
		 DataInputStream inFromServer = null;
		 
		 int numOfOutput = 0;
		 int numOfInput = 0;
		 
		 /*to establish the connection*/
		 try {
			 clientSocket = new Socket(argv[0], 8000);
			 
		 } catch (IOException ioe) { 
			 System.out.println("can not creat the socket!");
			 System.exit(1);
		 }
		 
		 System.out.println(argv[0] + " is listening to your request:"); 
		 
		 /*the input and output stream*/
		 try {
			 outToServer = 
	        	 new DataOutputStream(clientSocket.getOutputStream()); 
			 inFromServer = 
	        	 new DataInputStream(clientSocket.getInputStream());
	         
		 } catch (Exception ex) {
			 System.out.println("can not creat stream to server!");
			 System.exit(1);
		 }
		 
         /*get in the command from console*/
         command = stdIn.readLine();
         System.out.println("Header:\n");
		 
		 /*analyse the command*/
		 try{
			 
			 if(command.startsWith("GET")) {
				 
				 request = command + "\r\n" + "\r\n";
				 numOfOutput = numOfOutput + request.length();
				 outToServer.write(request.getBytes());//to sent the request to server
				
				 result = inFromServer.readLine();//get the response from server
				 numOfInput = numOfInput + result.length();
				 try{
					 do {
						 System.out.println(result);
						 result = inFromServer.readLine();
						 numOfInput = numOfInput + result.length();
						 
					 } while(result.length() > 0);//to get the header and then display it on the console
				 } catch(Exception e) {
				 }

				 /*transfer the content to a file designated by user*/
				 System.out.print("\n\n" + "Enter the name of the file to save:");
				 System.out.flush();
				 
				 File file = new File(stdIn.readLine());
				 FileOutputStream outFile = new FileOutputStream(file);
				 byte[] fileBytes = new byte[1024];
				 flag = inFromServer.read(fileBytes,0 ,1024);
				 numOfInput = numOfInput + flag;
				 outFile.write(fileBytes,0,flag);
				 while(flag != -1) {
					 flag = inFromServer.read(fileBytes,0 ,1024);
					 if(flag == 1024) {
						 
						 outFile.write(fileBytes,0,1024);
						 numOfInput = numOfInput + flag;
					 } else {
						 try {
							 outFile.write(fileBytes,0,flag);
						 } catch (IndexOutOfBoundsException iobe) {
							 System.out.println(iobe.toString());
						 }
						 numOfInput = numOfInput + flag;
					 }
				 } 
				 System.out.println("the number of bytes that it sends is " + numOfOutput);
				 System.out.println("the number of bytes that it receives is " + numOfInput);
				 outFile.flush();
				 outFile.close();
				 
			 } 
		 } catch (Exception exc) {
			 System.out.println(exc.toString());
		 }
	 }
 }