• 0

found my java problem need help solving!


Question

ok so i have found my java error! the real issue! now all i need to do is to solve it!!!

I need to send bytes over a socket connection ... simple as ... they have to be sent and received as bytes ... if someone could write me up a lil dummy program I can work with ? just convert a fixed string to bytes and send it as bytes and receive it as bytes the other end ... would help me out ALOT! then I can see it in action and fiddle with it

13 answers to this question

Recommended Posts

  • 0

ok so i have found my java error! the real issue! now all i need to do is to solve it!!!

I need to send bytes over a socket connection ... simple as ... they have to be sent and received as bytes ... if someone could write me up a lil dummy program I can work with ? just convert a fixed string to bytes and send it as bytes and receive it as bytes the other end ... would help me out ALOT! then I can see it in action and fiddle with it

You just need a server to listen on a port and client to connect to that port. Use this guide:

http://www.oracle.com/technetwork/java/socket-140484.html

But instead of doing "new Socket("kq6py", 4321)" on the client side, you need to pass an InetAddress object as the first parameter. The InetAddress is created by calling InetAddress.getByName() or InetAddress.getByAddress() static methods

  • 0

You just need a server to listen on a port and client to connect to that port. Use this guide:

http://www.oracle.co...ket-140484.html

But instead of doing "new Socket("kq6py", 4321)" on the client side, you need to pass an InetAddress object as the first parameter. The InetAddress is created by calling InetAddress.getByName() or InetAddress.getByAddress() static methods

I already have all the connections :p but I have been using printwriter I need to use bytearrayoutputstream ... but I am finding it difficult to find a tutorial which uses it over sockets

  • 0

I already have all the connections :p but I have been using printwriter I need to use bytearrayoutputstream ... but I am finding it difficult to find a tutorial which uses it over sockets

You don't use a ByteArrayOutputStream. That's something you can write to to build an in-memory byte array without having to grow it yourself.

You want to use the regular output stream provided by the socket and use the byte write methods: http://docs.oracle.com/javase/7/docs/api/java/io/OutputStream.html#write(byte[]) http://docs.oracle.com/javase/7/docs/api/java/io/OutputStream.html#write(byte[], int, int) http://docs.oracle.com/javase/7/docs/api/java/io/OutputStream.html#write(int)

String has a built-in getBytes() method that you can use to write as a byte array.

  • 0

You don't use a ByteArrayOutputStream. That's something you can write to to build an in-memory byte array without having to grow it yourself.

You want to use the regular output stream provided by the socket and use the byte write methods: http://docs.oracle.c...html#write(byte[]) http://docs.oracle.c...html#write(byte[], int, int) http://docs.oracle.c....html#write(int)

String has a built-in getBytes() method that you can use to write as a byte array.

ahh i see ... and what about the recieving end ? i tried the char writer like you previously gave me ... but for the decryption it has to be sent in bytes i cannot convert to string at any point until after it has been decrypted or i will get an error I set up a small single class test which encrypted and decrypted using only bytes ( which worked) then one which followed the same method of conversion as my current program and that just caused it to kill its self

  • 0

ahh i see ... and what about the recieving end ? i tried the char writer like you previously gave me ... but for the decryption it has to be sent in bytes i cannot convert to string at any point until after it has been decrypted or i will get an error I set up a small single class test which encrypted and decrypted using only bytes ( which worked) then one which followed the same method of conversion as my current program and that just caused it to kill its self

For that you could replace the CharArrayWriter with a ByteArrayOutputStream. Use the straight InputStream from the Socket though and use the read methods from that.

  • 0

For that you could replace the CharArrayWriter with a ByteArrayOutputStream. Use the straight InputStream from the Socket though and use the read methods from that.

could you give me an example code on how to implement it ? I really only learn via example sorry to be such a pain you have been a really really big help to me

  • 0

could you give me an example code on how to implement it ? I really only learn via example sorry to be such a pain you have been a really really big help to me

Pretty much the same as before except without Readers and such:

import java.io.*;
import java.net.*;
public class chatServer
{
public static void main (String[] args) throws IOException
{
  ServerSocket serverSocket = null;
  try
  {
   serverSocket = new ServerSocket (4444);
  }
  catch (IOException e)
  {
   System.err.println ("Could not listen on port: 4444.");
   System.exit (1);
  }
  System.out.println ("Server - Listening on port 4444");
  Socket clientSocket = null;
  try
  {
   clientSocket = serverSocket.accept ();
  }
  catch (IOException e)
  {
   System.err.println ("Accept failed."); System.exit(1);
  }
  OutputStream out = clientSocket.getOutputStream();
  BufferedReader in = clientSocket.getInputStream();
  String toClient, fromClient;
  toClient = "Hello";
  System.out.println ("Server Message: " + toClient);
  out.write(toClient.getBytes());
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] buf = new byte[4096];
int read;
while ((read=in.read(buf, 0, 4096))>0) {
System.out.println("x");
   os.write(buf, 0, read);

}
fromClient = os.toString(); //Or for bytes use toByteArray()
  System.out.println ("Client Message: " + fromClient);
  out.close ();
  in.close ();
  clientSocket.close ();
  serverSocket.close ();
}
}

It would definitely benefit you to learn to read the javadocs: http://docs.oracle.com/javase/7/docs/api/

  • 0

Pretty much the same as before except without Readers and such:

import java.io.*;
import java.net.*;
public class chatServer
{
public static void main (String[] args) throws IOException
{
  ServerSocket serverSocket = null;
  try
  {
   serverSocket = new ServerSocket (4444);
  }
  catch (IOException e)
  {
   System.err.println ("Could not listen on port: 4444.");
   System.exit (1);
  }
  System.out.println ("Server - Listening on port 4444");
  Socket clientSocket = null;
  try
  {
   clientSocket = serverSocket.accept ();
  }
  catch (IOException e)
  {
   System.err.println ("Accept failed."); System.exit(1);
  }
  OutputStream out = clientSocket.getOutputStream();
  BufferedReader in = clientSocket.getInputStream();
  String toClient, fromClient;
  toClient = "Hello";
  System.out.println ("Server Message: " + toClient);
  out.write(toClient.getBytes());
ByteArrayOutputStream os = new ByteArrayOutputStream();
byte[] buf = new byte[4096];
int read;
while ((read=in.read(buf, 0, 4096))>0) {
System.out.println("x");
   os.write(buf, 0, read);

}
fromClient = os.toString(); //Or for bytes use toByteArray()
  System.out.println ("Client Message: " + fromClient);
  out.close ();
  in.close ();
  clientSocket.close ();
  serverSocket.close ();
}
}

It would definitely benefit you to learn to read the javadocs: http://docs.oracle.c...ase/7/docs/api/

thanks i will try this and observe ... I know it would help to learn to read them ... but I honestly do not understand them ... I can only ever do stuff when I have seen it used before I need a context and I dunno why I cant grasp the docs probs not reading it completely (I skim)

  • 0

when I change it around it keeps saying

^

required: BufferedReader

found: InputStream

chatServer.java:36: error: no suitable method found for read(byte[],int,int)

while ((read=in.read(buf, 0, 4096))>0) {

^

method BufferedReader.read(char[],int,int) is not applicable

  • 0

Replace BufferedReader with InputStream.

The docs aren't all that hard to read. It's a listing of methods and fields from classes with (hopefully) a description of them and some even with examples. Of course finding the class you need if you don't know what to look for might be a little tricky.

  • 0

Replace BufferedReader with InputStream.

The docs aren't all that hard to read. It's a listing of methods and fields from classes with (hopefully) a description of them and some even with examples. Of course finding the class you need if you don't know what to look for might be a little tricky.

I got it working ish haha just working through the bugs (only got it working as in no errors lol.... and sending data... yet to get everything sending 100% )

  • 0

Replace BufferedReader with InputStream.

The docs aren't all that hard to read. It's a listing of methods and fields from classes with (hopefully) a description of them and some even with examples. Of course finding the class you need if you don't know what to look for might be a little tricky.

ok new problem haha... I am sending the bytes... but when the bytes arrive they are different? I think its byting my bytes?

  • 0

Replace BufferedReader with InputStream.

The docs aren't all that hard to read. It's a listing of methods and fields from classes with (hopefully) a description of them and some even with examples. Of course finding the class you need if you don't know what to look for might be a little tricky.

I got it working! its a christmas miracle! 100% working encryption decryption !! :D

This topic is now closed to further replies.
  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Posts

    • HomeBank 5.10.1 by Razvan Serea HomeBank is a free software (as in "free speech" and also as in "free beer") that will assist you to manage your personal accounting. It is designed to easy to use and be able to analyse your personal finance and budget in detail using powerful filtering tools and beautiful charts. If you are looking for a completely free and easy application to manage your personal accounting, budget, finance then HomeBank should be the software of choice. HomeBank also benefits of more than 19 years of user experience and feedback, and is translated by its users in around 56 languages. Highlights: Cross platform, supports GNU/Linux, Microsoft Windows, Mac OS X Import easily from Intuit Quicken, Microsoft Money or other software Import bank account statements (OFX, QIF, CSV, QFX) Duplicate transaction detection Automatic cheque numbering Various account types : Bank, Cash, Asset, Credit card, Liability Scheduled transaction Category split Internal transfer Month/Annual budget Dynamic powerful reports with charts Automatic category/payee assignment Vehicule cost HomeBank 5.10.1 changelog: change: the input field helper icon + fixed some spacing inconsistency change: transaction, added some missing input tooltips and reworked existing change: category, payee and tag window add input now have a tooltip and button change: split window, refactored the layout change: split window, add display of memo and date wish : #2106800 budget report option to exclude transfers from unbudgeted line bugfix: prevent deletion of non pending transaction when rejecting bugfix: transaction warning for no rate faultly showing in transfer bugfix: report missing space for filter tooltip icon bugfix: budget report missing filter tooltip bugfix: manage account closed icon was hidding budget icon bugfix: #2154771 view transcations requires hitting Escape or X twice to close dialog bugfix: #2154337 transfer to/from closed account with different currency don't show the amount bugfix: #2154234 scheduled transaction recurring pattern daily value limited to 100 bugfix: #2149897 view split for closed accounts bugfix: #2148561 global time chart do not shows current period by default bugfix: #2148456 the main screen Total Chart is no longer showing an overall total bugfix: #2147497 editing a transaction resets scroll position bugfix: #2147377 balance mixup with transaction same day sort by amount bugfix: #2147052 quarter are wrong when fiscal year is jan 1 bugfix: #2147048 all events for the month are late but today is only the 1st bugfix: #2144993 impossible to search for transactions by value for values >999,99 bugfix: #2144698 adding new Category/Payee/Tags requires hitting -Enter- bugfix: #2144419 QIF Account name detection fail on import bugfix: #2142349 can't delete account groups bugfix: #2139409 account maximum limit is not fully used (example credit card) bugfix: #2133783 transfers shouldn't add to dashboard top spending reports Download: HomeBank 5.10.1 | 20.5 MB (Open Source) Download: 3rd party packages (macOSX. Ubuntu...etc) View: HomeBank Website | Support | Features | Screenshot Get alerted to all of our Software updates on Twitter at @NeowinSoftware
    • Same, price was right for my Home, laptop, phone. Works great!
    • Brave and Firefox. I’ve been using them as my primary browsers for a while now, perfect combo
    • They want Ring 0 access. Should be a hard no. A middle ground needs to be found.
  • Recent Achievements

    • One Year In
      Primer1st earned a badge
      One Year In
    • Experienced
      JayZJay went up a rank
      Experienced
    • Reacting Well
      Sir_Timbit earned a badge
      Reacting Well
    • Week One Done
      rubentuben8 earned a badge
      Week One Done
    • Week One Done
      ARaclen earned a badge
      Week One Done
  • Popular Contributors

    1. 1
      +primortal
      524
    2. 2
      PsYcHoKiLLa
      232
    3. 3
      Edouard
      135
    4. 4
      ATLien_0
      88
    5. 5
      Steven P.
      83
  • Tell a friend

    Love Neowin? Tell a friend!