ArrayOutOfBoundsIndexException

Core Library Questions

jfp868

ArrayOutOfBoundsIndexException

in Core Library Questions • 1 year ago

Hi,

I am creating an RTS game involving a server and a client. I have recently been getting an ArrayOutOfBoundsIndexException error that I cant seem to solve. Any help would be appreciated.

this is the server

import processing.net.*; //Imports processing.net.* Library -- for server
Server gameServer; //Server -- This program is the server
Client gameClient; //Client -- The partner program is the Client
String input; //Stores data recieved from Client
int data[]; //Separates data stored in input
void ServerSetup(){
if(NumberOfUnits > 0){ //If you have any units
//Send the array indexes and Team Coordinates to the client
gameServer.write(0 + " " + xCoordinate + " " + yCoordinate + "\n");
}
//Receive data from client
gameClient = gameServer.available();
//If the Client is sending information
if (gameClient != null){
//Put the input into a string
input = gameClient.readString();
//Separate the elements of the string
if(input.indexOf("\n") != -1){
input = input.substring(0, input.indexOf("\n")); // Only up to the newline
}
//Split values into an array
data = int(split(input, ' '));
//Use the values to generate the positions and images of the opposing team
println(data[0]); //The ArrayOutOfBoundsIndexException occurs between 0 and 5 minutes randomly on any of these println lines
println(data[1]);
println(data[2]);
}
}

this is the client

import processing.net.*; //Imports processing.net.* Library -- for server
Client gameClient; //Client -- The partner program is the Client
String input; //Stores data recieved from Client
int data[]; //Separates data stored in input
void ClientSetup() {
if(NumberOfUnits > 0){
//Send the array indexes and Team Coordinates to the client
gameClient.write(0 + " " + xCoordinate + " " + yCoordinate + "\n");
}
//If the Server is sending information
if (gameClient.available() > 0) {
//Put the input into a string
input = gameClient.readString();
//Separate the elements of the string
if(input.indexOf("\n") != -1){
input = input.substring(0, input.indexOf("\n"));
}
//Split values into an array
data = int(split(input, ' '));
//Use the values to generate the positions and images of the opposing team
println(data[0]);
println(data[1]);
println(data[2]);
}
}

Replies(9)

calsign

Re: ArrayOutOfBoundsIndexException

1 year ago

This error only occurs in the Server code?
The problem, then, is likely found in the data being sent by the Client, specifically where you set the values of xCoordinate and yCoordinate.

I would print 0 + " " + xCoordinate + " " + yCoordinate + "\n" before you send it so that you can see what is going on.

jfp868

Re: ArrayOutOfBoundsIndexException

1 year ago

I ran the program with a println statement and received the following output

This output was received countless times and is correct and normal

0 //Index 0

-800 //x-value

1440 //y-value

0 -800 1440 //0 + " " + xCoordinate + " " + yCoordinate + "\n"

//newline because of the "\n"

This was the output during the instance of the error - without moving the unit

0 //Index 0

-800 //x-value

0 //???

0 -800 1440 //0 + " " + xCoordinate + " " + yCoordinate + "\n"

//newline because of the "\n"

1440 // ??? supposed to be y-value

calsign

Re: ArrayOutOfBoundsIndexException

1 year ago

So, the error is occurring Server side, which means that it must be broadcast incorrectly on the Client...
Is that what is being received or broadcast?
Now you need to figure out exactly where the change occurs, using multiple println() statements.

jfp868

Re: ArrayOutOfBoundsIndexException

1 year ago

Which ever program receives the data will freeze. If the Client sends information to the server the server will freeze and if the Server sends information to the client the client will freeze. However not instantly, usually around 2 minutes after data starts to be sent

calsign

Re: ArrayOutOfBoundsIndexException

1 year ago

Yes, that's when you receive the error. But where, exactly, in your code, does the change from 1440 to 0 occur?

jfp868

Re: ArrayOutOfBoundsIndexException

1 year ago

I ran it again,

the client this time was doing the println and continually prints out

"0 -800 1440"

the server who was receiving the data printed

0 //Correct - index 0

-800 //Correct - x-coordinate

1440 //Correct - y-coordinate

0 //Restart of cycle - correct - index 0

-8 //incorrect should be -800

ArrayIndexOutOfBoundsException: 2

calsign

Re: ArrayOutOfBoundsIndexException

1 year ago

My guess is that your data travelling between the Server and Client is getting corrupted.
Just check to see if the data can be read properly before attempting to do so.

If this lack of functionality every two minutes is disruptive to your program, then you're going to have to do something else...

jfp868

Re: ArrayOutOfBoundsIndexException

1 year ago

The thing is though, its not the data that is the problem, the array data[] is what is causing problems. It eventually does not have the proper offset causing the ArrayOutOfBoundsIndexException this is what the problem is, if it were the data, the units would just be jumping around the screen.

calsign

Re: ArrayOutOfBoundsIndexException

1 year ago

The only thing that could really make sense, now, is that the connection is dropping spaces - or, possibly, entire sequences of text...
As it is, I have no clue what you can do to fix it.
(And, if it's something else, I don't know what's going wrong.)

Also, you say that the values change to incorrect values - that is why I think the connection is dropping things.
There is simply no other explanation.

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