Problem in file transfer

[Muddasani Rohit Reddy]

Hello everyone,
I had a problem in doing my mini-project last week and the problem is that when I am performing file transfer using TCP, the file on being received on the client side is having some dummy characters also along with the original file. I have tried a lot but could not eliminate those garbage characters......Please help me out with this and I will be very thankful to you people. I am attaching the code of both server and client in this post.

Server:

import java.io.*;
import java.net.*;
import java.util.*;
 
class TCPServer
{
 
 public static void main(String args[])
 throws Exception
 {
  ServerSocket servSocket = new ServerSocket(1234);
  Socket s1 = null;
  try
  {
   s1 = servSocket.accept();
   System.out.println("The client is connected.");
  }catch (Exception e){}
 
  int count;
 // String s3 = new String();
 // String s2 = new String();
 // String s4 = new String();
  String s5 = "Encrypted";
  OutputStream o = (s1.getOutputStream());
  InputStream f1 = s1.getInputStream();
  PrintWriter pw = new PrintWriter(s1.getOutputStream(),true);
  byte b1[] = new byte[1024];
  try{
  f1.read(b1);
  }catch(Exception e){}
  
  String s=new String(b1);
  System.out.println(s);
  /*StringTokenizer st = new StringTokenizer(s);
  count = st.countTokens();
 
  System.out.println("The number of tokens is: " + count);
  s2 = st.nextToken();
  if (s2.compareTo("GET") == 0 )
  {
   s3 = st.nextToken();
   s4 = s3.substring(1);
  }*/
  File fi1 = new File(s);
  File fi2 = new File(s5);
  System.out.println("The required file is: " + s);
  if (fi1.exists() == true)
  {
   int n = (int)fi1.length();
   System.out.println("File exists");
   try
  {
   int i;
   InputStream f0 = new FileInputStream(fi1);
   OutputStream f2 = new FileOutputStream(fi2);
 
   do
   {
    i = f0.read();
    if(i!=-1)
    {
     f2.write((char) (i+3));
    }
   }while(i!= -1);
 
   f0.close();
   f2.close();
  }catch(Exception e){}
 
   
   FileInputStream ifs = new FileInputStream(fi2);
//   byte b[] = new byte[n];
   System.out.println("The size of the file is :" + n);
   String str1="HTTP/1.0 200 OK\r\n";
   String str2="Server: simple web server\r\n";
   String str3="Content-Type: text/html\r\n";
   String str4="Content-Length: "+n+"\r\n";
           
   pw.println(str1);
   pw.println(str2);
   pw.println(str3);
   pw.println(str4);
      
   byte b[]=new byte[n];
   ifs.read(b);
   o.write(b);

  
     
   ifs.close();
    
   int x = f1.available();
   if (x!=0)
   {
    byte b2[] = new byte[100];
    while((n=f1.read(b2))!=-1)
    {
     String str = new String(b2);
     System.out.println(str);
    }
    f1.close();
   }
  }
  else
  { 
   System.out.println("File does not exist");
  }
  o.close();
  s1.close();
  servSocket.close();
 }
} 
 

Client:

import java.io.*;
import java.net.*;
import java.lang.*;
import java.util.*;
 
class TCPClient
{
 public static void main(String args[]) 
 throws Exception
 {
  Socket s = new Socket(InetAddress.getLocalHost(),1234);
  System.out.print("Enter the name of the file required :");
  String s1 = "Encrpypted";
  String s2 = "Original";
  InputStream is=(s.getInputStream());
  OutputStream os= s.getOutputStream();
  BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
  String st = br.readLine();
  os.write(st.getBytes());
  BufferedReader br1 = new BufferedReader(new InputStreamReader(s.getInputStream()));
    
  byte b[]=new byte[1024];
  String sb = new String();
  int n;
  File fi1 = new File(s1);
  File fi2 = new File(s2);
  PrintWriter pw = new PrintWriter(new FileOutputStream(fi1),true);
  OutputStream o1 = new FileOutputStream(fi1);
  InputStream i1 = new FileInputStream(fi1);
  OutputStream o2 = new FileOutputStream(fi2);
  InputStream i2 = new FileInputStream(fi2);
  //BufferedReader br2 = new BufferedReader(new FileInputStream(fi1));
  String st1="HTTP/1.0 200 OK";
  String st2 = "The file is not in HTTP format...cannot accept it";
  
  /*while((n=is.read(b))!=-1)
  {
   String str = new String(b);
   System.out.println(str);   
   if(str.compareTo(st1) != 0)
   {
   System.out.println("The file cannot be accepted as it is not in HTTP format");
   os.write(st2.getBytes());
   break;
   }    
   byte b1[] = str.getBytes();
   o1.write(b1);
  }
  o1.close();*/
  String str1 = new String();
  String str2 = br1.readLine();
  if(str2.compareTo(st1)!=0)
  {
   System.out.println("The file cannot be accepted as it is not in HTTP format");
   os.write(st2.getBytes());
   os.close();
   s.close();
   System.exit(0);
  }    
  String str3 = br1.readLine();
  String str4 = br1.readLine();
  String str5 = br1.readLine();
  String str6 = br1.readLine();
  String str7 = br1.readLine();
  String str8 = br1.readLine();
  String str9 = br1.readLine();
  System.out.println(str2);
  System.out.println(str3);
  System.out.println(str4);
  System.out.println(str5);
  System.out.println(str6);
  System.out.println(str7);
  System.out.println(str8);
  
 
 
 
  while((str1=br1.readLine()) != null)
  {
  //System.out.println(str1);
  pw.println(str1);
  }
   
  /*n=0;
  byte bst[]=new byte[1024];
  while((n=is.read(bst))!=-1)
  o1.write(bst,0,n);*/
  
 
  o1.close();
 
  int j=0;
  j = i1.read();
  while(j!=-1)
  {
   o2.write((char) (j-3));
   j = i1.read();
  }
  i1.close();
  o2.close();
  os.close();
  is.close();
  for(int i=0;i<fi2.length();i++)
  {
   //System.out.print((char)i2.read());
  }
  i2.close();
  
 } 
}

Please help me out with this.....Thank you.
[ October 09, 2008: Message edited by: Ulf Dittmer ]

[Ulf Dittmer]

Welcome to JavaRanch.

Please UseCodeTags when posting code of any length. It's unnecessarily hard to read, and will deter many people from looking at it. I have added those for you, but please remember to do that from now on.

I haven't looked at the code in detail -there are so many streams and readers that it's hard to figure out what's being used for what- but I noticed a couple of things. First, never do something like "}catch(Exception e){}" in I/O code. How will you know that there are problems? At the least, print a message to the console.

Secondly, you will get extraneous characters through the "pw.println(str1); pw.println(str2); pw.println(str3); pw.println(str4);" statements. Those strings already have "\r\n" at the end, so if you use "println" -instead of "print"- there will be extra newlines and possible extra carriage returns.

Lastly, you may run into problems if client and server don't run on the same machine. That's because you're not specifically dealing with encoding in the "new String" and "String.getBytes" calls. Those will use the platform default encoding, which may differ on different machines.
[ October 09, 2008: Message edited by: Ulf Dittmer ]

[Muddasani Rohit Reddy]

Thank you Ulf for your valuable suggestions.I am still an amateur at programming and these tips from you would definitely help me.I would try out the suggestions given by you , and thank you for taking the pains to go through my code.

[Muddasani Rohit Reddy]

Thank you Ulf for your valuable suggestions.I am still an amateur at programming and these tips from you would definitely help me.I would try out the suggestions given by you , and thank you for taking the pains to go through my code.