Byte to String problem

[Johannes Thorén]

I'm trying to make a simple "Hangman-game". I've got 3 classes that's interesting in this case.

My problem is that, I'm sending a message to my server, containing of a string "start_game". In my connectionhandler I've said that "If the message is start_game, run the method run() in "HangmanGame". The problem is that it doesint call the method "run()" but instead calls "guess()". (it should only call guess if the string sent is only 1 char long).

The second problem is that it's saying "Some of the data got lost..." since i specified that the message returned from the server should be of the same size as the message sent. The problem is, I wont know beforehand how big the return message will be.

Here are the classes:

SimpleClient.java

byte[] toServer = message.getBytes();
		out.write(toServer, 0, toServer.length);
		out.flush();

		byte[] fromServer = new byte[10000];
		int n = in.read(fromServer, 0, fromServer.length);
		if (n != fromServer.length) {
			System.out.println("Some data are lost ...");
		}
		System.out.println(new String(fromServer));

SimpleConnectionHandler (hg is a HangmanGame object)

public void run() {
		BufferedInputStream in;
		BufferedOutputStream out;

		try {
			in = new BufferedInputStream(clientSocket.getInputStream());
			out = new BufferedOutputStream(clientSocket.getOutputStream());
		} catch (IOException e) {
			System.out.println(e.toString());
			return;
		}

		try {
			byte[] msg = new byte[4096];
			int bytesRead = 0;
			int n;

			while((n = in.read(msg, bytesRead, 256)) != -1) {
				bytesRead += n;
				if (bytesRead == 4096) {
					break;
				}
				if (in.available() == 0) {
					break;
				}
			}
			System.out.print(msg.toString());
			if(msg.toString()=="start_game"){
				hg.run();
			}else if(msg.toString().length()==1){
				hg.run();
			}
			
			StringBuilder answer = hg.getAnswer();
			System.out.print(answer);
			msg = answer.toString().getBytes();
			
			out.write(msg);

HangmanGame

import java.util.Random;

import fileread.ReadFromFile;


public class HangmanGame {
	private String 				answer;
	private int 				lives;
	private int					score;
	private int					numberWords = 3;
	private StringBuilder		currentWord;
	private String[]			words;
	private String				chosedWord;
	private StringBuilder 		sb;
	Random 						r = new Random();
	private ReadFromFile		fr = new ReadFromFile();
	
	
	public HangmanGame() {
		sb			=	new StringBuilder();
	}
	
	
	public void run(){
		words		=	fr.readFromFile("words",words,numberWords);
		chosedWord	=	words[r.nextInt(words.length)];
		lives		=	5;
		
		for(int i=0; i<chosedWord.length(); i++){
			currentWord.append(" _");
		}
		sb.append(currentWord);
		sb.append("\n\n Lives: ");
		sb.append(lives);
		System.out.println(sb);
	}


	public void guess(String guess) {
		char ch 	= 	guess.charAt(0);
		sb			=	new StringBuilder();
		StringBuilder sBuild = new StringBuilder();
		sBuild.append(currentWord);
		
		if(guess.length()><2){
			if(chosedWord.indexOf(ch)==-1){
				lives--;
				sb.append("\n\n Lives left: ");
				sb.append(lives);
				sb.append(currentWord);
				
			}else if(chosedWord.indexOf(ch)!=-1){
				score++;
				for(int i=0;i<chosedWord.length();i++){
					if(chosedWord.charAt(i)==ch){
						sBuild.deleteCharAt((i*2)+1);
						sBuild.insert((i*2)+1, ch);
					}
				}
				if(currentWord.equals(chosedWord)){
					sb.append(chosedWord);
					sb.append(" ");
					sb.append("Grattis!");
				}
			}
			if(guess.length()>1){
				if(chosedWord.compareToIgnoreCase(guess)==0){
					sb.append(chosedWord);
					sb.append(" ");
					sb.append("Grattis!");
				}
				if(chosedWord.compareToIgnoreCase(guess)!=0){
					lives--;
					sb.append(currentWord);
					sb.append("\n\n");
					sb.append("Lives left: ");
					sb.append(lives);
				}
			}
		}
	}
	
	public StringBuilder getAnswer(){
		System.out.print(sb);
		return sb;
	}

}

Thanks in forehand

Kind Regards,
Drace

[Johannes Thorén]

And yeah the size on fromServer is way to big, but i get the same when i try it smaller.

[Johannes Thorén]

Now i realized that I'm comparing strings by using == operator. But even when i changed it to .equalsIgnoreCase() it doesint work :/

[John Jai]

System.out.print(msg.toString());  
if(msg.toString()=="start_game"){  
         hg.run();  
}else if(msg.toString().length()==1){  
         hg.run();  
}

Seems that both conditions call the run() method.... What you get when you try to print the msg.toString()

[Johannes Thorén]

I call the run method in both, but thats not the problem. I cant print the msg.toString() since its on the server side. But when i print the byte by sending it back out.write(msg) i get "start_game". But the comparing does not work. It doesint return 0 even tho their equal.

"start_game".compareTo(msg.toString())

[Joanne Neal]

Johannes Thorén wrote:I call the run method in both, but thats not the problem. I cant print the msg.toString() since its on the server side. But when i print the byte by sending it back out.write(msg) i get "start_game". But the comparing does not work. It doesint return 0 even tho their equal.

"start_game".compareTo(msg.toString())

If msg does contain start_game then that should work. Are you sure there are no spaces at the beginning or end ? Try posting your latest code - the problem may be elsewhere

[Johannes Thorén]

msg is an array of bytes containing "start_game". So msg.toString() should contain a string with the content "start_game" right? Here's the new code:

String startString="start_game";
			if(startString.compareToIgnoreCase(msg.toString())==0){
				hg.run();
			}else if(msg.toString().length()==1){
				hg.guess(new String(msg));
			}
			
			StringBuilder answer = hg.getAnswer();
			msg = answer.toString().getBytes();

out.write(msg);

And the client that sends the message to the server side is:

String ip = "127.0.0.1";
		String message = "start_game";

byte[] toServer = message.getBytes();
		out.write(toServer, 0, toServer.length);
		out.flush();

		byte[] fromServer = new byte[10000];
		int n = in.read(fromServer, 0, fromServer.length);
		if (n != fromServer.length) {
			System.out.println("Some data are lost ...");
		}
		System.out.println(new String(fromServer));

[Harsha Smith]

byte [] array = "start_game".getBytes();
System.out.println(new String(array));

[Harsha Smith]

Johannes Thorén wrote:msg is an array of bytes containing "start_game". So msg.toString() should contain a string with the content "start_game" right?

wrong. Look at the above piece of code

[Johannes Thorén]

Harsha Smith wrote:

Johannes Thorén wrote:msg is an array of bytes containing "start_game". So msg.toString() should contain a string with the content "start_game" right?

wrong. Look at the above piece of code

But that's on the client side.

1. I make a string "start_game"
2. convert it to bytes to send to the server side.
3. recieve the bytes on server side
4. convert the bytes to a string
5. compare the new string with the string "start_game".

[Harsha Smith]

y don't use equalsIgnoreCase or contains method instead of compareToIgnoreCase?

[Johannes Thorén]

Harsha Smith wrote:y don't use equalsIgnoreCase or contains method instead of compareToIgnoreCase?

+100k


Thank you, did not see that one

Altho it does not work. But now i realize that i only take 4096 bytes out of the message from the client. But that should be enough for "start_game" right?

[Johannes Thorén]

Maybe the fact that the byte array is 4096 bytes long makes the equalsIgnoreCase false? Even if it contains start_game it still contains empty byte-slots aswell?

[Harsha Smith]

Did you try removing the white spaces as told?

msg = msg.trim();

[Johannes Thorén]

I could not trim a byte array, but i tried to make a string and then trim the string.

[Johannes Thorén]

I think it works now tho. But i dont get any result from my game-class hehe. But thats another problem

[Johannes Thorén]

This is the new problem. When i call "run()" i append information to the StringBuilder sb. And when i fetch the sb using method getAnswer(), it is empty.
Here's the parts of the game-glass:

public class HangmanGame {
	private String 				answer;
	private int 				lives;
	private int					score;
	private int					numberWords = 2;
	private StringBuilder		currentWord;
	private String[]			words;
	private String				chosedWord;
	private StringBuilder 		sb;
	Random 						r = new Random();
	private ReadFromFile		fr = new ReadFromFile();
	
	
	public HangmanGame() {
		sb			=	new StringBuilder();
		currentWord	=	new StringBuilder();
		words		=	new String[numberWords];
	}

public void run(){
		words		=	fr.readFromFile("words",words,numberWords);
		chosedWord	=	words[r.nextInt(words.length)];
		lives		=	5;
		
		for(int i=0; i<chosedWord.length(); i++){
			currentWord.append(" _");
		}
		sb.append(currentWord);
		sb.append("\n\n Lives: ");
		sb.append(lives);
		System.out.println(sb);
	}

public StringBuilder getAnswer(){
		return sb;
	}

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