Applet to Php to MySql

[Lyn Emmilie]

Hi everyone

First of all, I just joined the ranch
Pardon me if my question has been answered before, because I have searched through the forum and there was none that could answer my problem
(or none that I understand)

I'm creating a game where at the end, I'll send an int score and String name to a php which will store it in web database.
I'm using a paid server for this.

I have a Java applet that is embedded in a mypage.com/play.php
I have a php for retrieving the url from the applet (or so it seems..) in mypage.com/test.php

Basically I followed this tutorial from http://woogley.net/misc/Highscore/
Now the Java console tells me java.lang.ArrayIndexOutOfBoundsException: 0
which comes from the line from Save.java

My DBComm looks like this

import java.io.*;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.ArrayList;

public class DBComm
{

    public static final String SCRIPT_URL = "http://mypage.com/test.php";
    protected static String error = "No errors";
    protected static boolean isError = false;

    DBComm()
    {
    }
    
    

    public static String[] read(String s)
    {
        String s1 = "http://mypage.com/test.php?access_code=021&" + s;
        URL url = null;
        try
        {
            url = new URL(s1);
            System.out.println("url read : " +s1);

        }
        catch(MalformedURLException malformedurlexception)
        {
        	System.out.println("bad url");
            error = "Bad URL";
            isError = true;
            return null;
        }
        BufferedReader bufferedreader = null;
        try
        {
            bufferedreader = new BufferedReader(new InputStreamReader(url.openStream()));
            System.out.println("bufferedreader in");
        }
        catch(IOException ioexception)
        {
        	System.out.println("cant connect highscore table");
            error = "Could not connect to highscore table";
            isError = true;
            return null;
        }
        
        ArrayList arraylist = new ArrayList();       /****** Maybe this also contributes to java.lang.ArrayIndexOutOfBoundsException *****/  
        String s2;
        try
        {
            while((s2 = bufferedreader.readLine()) != null) 
            {
                arraylist.add(s2);
                System.out.println("arraylist s2 : "+s2);
                System.out.println("arraylist enter : "+arraylist);
            }
        }
        catch(IOException ioexception1)
        {
        	System.out.println("cant connect highscore table");
            error = "Could not connect to highscore table";
            isError = true;
            return null;
        }
        String as[] = new String[arraylist.size()];
        for(int i = 0; i < as.length; i++)
        {
            as[i] = (String)arraylist.get(i);
            System.out.println("as[i]: "+as[i]);
        }
        System.out.println(as);
        return as;
    }

    public static boolean isError()
    {
        if(!isError)
        {
            return false;
        } else
        {
            isError = false;
            return true;
        }
    }

    public static String getError()
    {
        String s = "" + error;
        error = "No errors";
        return s;
    }

}

While this is my Save.java

import org.game.gameplay.DBComm;
import org.game.gameplay.Score;
import org.game.gameplay.ScoreConsumer;

public class Save implements ScoreConsumer{
	private Score sc;
	private boolean error;
	private String errorMsg;
	
	@Override
	public void dealWithScore(Score score) {
		this.sc = score;
		System.out.println(sc.getName() + sc.getScore());
	}
	
	 public void submit()
	    {
		 	System.out.println("enter submit method " +sc.getName() + sc.getScore());
	        String as[] = DBComm.read("action=submit&admin_user=dbuser&admin_pass=dbpassword&name=" + sc.getName() + "&score=" + sc.getScore());
	               
	        if(as == null)
	        {
	            error = true;
	            errorMsg = "DB error";
	        } 
	        else if(as[0]==("0"))               /****** Here's the java.lang.ArrayIndexOutOfBoundsException coming from *****/
	        {
	        	System.out.println("db error");
	        	error = true;
	        	errorMsg = "DB error";
	        }
	    }
	 
	 protected String[] format(String s)
	    {
	        String as[] = new String[2];

	        if(s.indexOf(" ") < 0)
	        {
	            as[0] = "" + s;
	            as[1] = "N/A";
	            return as;
	        } else
	        {
	            as[0] = s.substring(0, s.lastIndexOf(" "));
	            as[1] = s.substring(s.lastIndexOf(" "), s.length());
	            return as;
	        }
	    }

}

I know no one likes to debug someone else's code, but I'm still open to any other suggestions and I want to learn,
honestly, this is my first time doing networking with applet, so I'm not sure where to start and why to use what packages.

I'm thinking of other ways, such as storing the scores in a .txt file in the same directory (eg: mypage.com/score.txt)
and use php to use them later.
But I'm not sure how

Thanks

[Swastik Dey]

Which code is leading the exception DBComm or Save?

[Swastik Dey]

as[0], are you sure that length of as is >0? Another point, the way you are comparing string
as[0]=="0" // this is a reference comparison not a value comparison, you need to use the equals method

as[0].equals("0")

[Lyn Emmilie]

Swastik Dey wrote:Which code is leading the exception DBComm or Save?

I already marked it in my Save.

Swastik Dey wrote:as[0], are you sure that length of as is >0? Another point, the way you are comparing string
as[0]=="0" // this is a reference comparison not a value comparison, you need to use the equals method

as[0].equals("0")

It originally is as[0].equals("0")
it didnt work, spits out the same java.lang.ArrayIndexOutOfBoundsException so i tried to change it to as[0]=="0"
also, the same error.

like I said, I'm not sure of the code since I got it from http://woogley.net/misc/Highscore/

I especially not know the purpose of the arraylist in the first place. What it's supposed to contain, huh?

Thanks for replying

[Swastik Dey]

As per my understanding, the number of lines to be returned from server is not known, that's why the ArrayList is being used.

[Lyn Emmilie]

That makes sense. In this case I'm not sure what should the arraylist carry anyway

Hey I have a new code, which isn't working well but can you help me, Swastik?
I got this from https://coderanch.com/t/437651/Applets/java/Applet-PHP
but he used getCodeBase()

Is my URL in the correct format?
I have my php file at mypage.com/test2.php where I receive 2 variables as POST

public class Save implements ScoreConsumer{

	private Score sc;
	private Font font;
	private boolean error;
	private String errorMsg;
	
	@Override
	public void dealWithScore(Score score) {
		this.sc = score;
		System.out.println(sc.getName() + sc.getScore());
	}
	
	public boolean postResults()         /***** I call this method to start saving the highscore *****/
 	  throws MalformedURLException, IOException { 
	boolean success = false;
	
	String parametersAsString = "name=" + sc.getName() + "&score=" + sc.getScore();		 

	byte[] parameterAsBytes = parametersAsString.getBytes(); 

	URL url =  null;

	url = new URL("http://mypage.com/test2.php?");     /**** will the POST go here?***/
	
	URLConnection con = url.openConnection(); 
	((HttpURLConnection) con).setRequestMethod("POST");
	con.setDoOutput(true);
	con.setDoInput(true);
	con.setUseCaches(false);

	OutputStream oStream = con.getOutputStream(); 
	oStream.write(parameterAsBytes); 
	oStream.flush(); 

	BufferedReader iStream = new BufferedReader(new InputStreamReader(con.getInputStream()));

	String aLine = iStream.readLine();

	while(aLine != null) 
	{
		if(aLine.contains("success"))
			System.out.println("Success");
			success = true;
		if(aLine.equals("")) break;
			aLine = iStream.readLine();
	}

	iStream.close(); 
	oStream.close(); 
	  
	return success;
	  
}
}

and my test2.php

<?
	$arr = array();
	
		$arr[0] = $_POST["name"];
		$arr[1] = $_POST["score"];

		// Connect database.
		$host="localhost";
		$db_user="user"; 
		$db_password="pass";
		$database="dbname";
		$db = mysql_connect($host,$db_user,$db_password);
		if (!($db)){
			echo "SQL ERROR: Connection failed: "; 
			die('SQL ERROR: Connection failed: ' . mysql_error($db));
		}

		$dbSelected = mysql_select_db($database,$db);

		if(!$dbSelected)
		{
			echo "SQL ERROR: Selection Failed ";
			die("Can\'t use ".$database." ".mysql_error());
		}

		$sql = "insert into highscore (name, score) values ('$arr[0]','$arr[1]')";

		if (!($db2 = mysql_query($sql, $db))){
			echo "SQL INSERT ";
			die('SQL INSERT ERROR: '.mysql_error(). " - Query was: {$sql}");
		}

		echo "success"; //RESPOND TO APPLET
	//}
?>

Then when I call the postResults method, nothing happens. My console also isn't showing any error, and nothing is stored in my database >_<

Sorry if this is taking your time.. I really appreciate that you try to help ^^

[Swastik Dey]

I don't know much about php, however the java code is looking fine to me. What error are you getting?

[Lyn Emmilie]

Oh I see..

That's the thing, I'm not getting any error so I don't know where to look.
Is the Java supposed to work?
I mean,
my applet is trying to connect to the URL.. maybe it didnt succeed?

[Swastik Dey]

May be. As far as the java code is concerned, nothing looks wrong with the connectivity part.

[Lyn Emmilie]

Oh you're right.
It's the php after all. A little mistake at the Insert statement.
I'll edit the code for the purpose of others to learn.

Thanks for reviewing my Java code, Swastik