Hello,

I am trying to use the server/client class to receive data from a webpage. Basically, I send an AJAX call from the webpage, and I use processing to parse out the information I need (its a midi note that I am sending). It works great, except that it only lets me send about 6 notes, and then it crashes saying:

"Exception in thread "Animation Thread" java.lang.StringIndexOutOfBoundsException: String index out of range: -3"

Here is my code:

Code:

import processing.net.*;
import themidibus.*; //Import the library

MidiBus myBus; // The MidiBus


int port = 10002;
boolean myServerRunning = true;
int bgColor = 0;
int direction = 1;
int textLine = 60;


Server myServer;

void setup() {
  size(800,800);
  background(0);
  textFont(createFont("SanSerif", 16));
  myServer = new Server(this, port); // Starts a myServer on port 10002

  MidiBus.list(); // List all available Midi devices on STDOUT. This will show each device's index and name.
  myBus = new MidiBus(this, 2, 10); // Create a new MidiBus with no input device and the default Java Sound Synthesizer as the output device.
}

void draw() {
  int channel = 0;
  int pitch = 64;
  int velocity = 127;
  int number = 0;
  int value = 90;	
  if (myServerRunning == true)
  {
    text("server", 15, 45);
    Client thisClient = myServer.available();
    if (thisClient != null) {
      if (thisClient.available() > 0) {
        String content = thisClient.readString();
        int a = content.indexOf("/?");
        int b = content.indexOf("HTTP");
        String c = content.substring(a + 2, b - 1);
        println(content.substring(a + 2, b));
        int i = parseInt(c); 
        myBus.sendNoteOn(channel, i, velocity); // Send a Midi noteOn
        delay(200);
        myBus.sendNoteOff(channel, i, velocity); // Send a Midi nodeOff
        text("mesage from: " + i, 15, textLine);
        textLine = textLine + 35;
        thisClient.stop();
      }
    }
  } 

}

 

Any help would be appreciated. Thanks.

-Thomas

Heres the entire error:

Exception in thread "Animation Thread" java.lang.StringIndexOutOfBoundsException: String index out of range: -3
     at java.lang.String.substring(Unknown Source)
     at midiserver.draw(midiserver.java:92)
     at processing.core.PApplet.handleDraw(PApplet.java:1423)
     at processing.core.PApplet.run(PApplet.java:1328)
     at java.lang.Thread.run(Unknown Source)

Yes, I am using Javascript from the webpage to send the AJAX call (Asynchronous Javascript and XML).

It actually works fine until it freaks out, and it won't let me check the result... as in, it gives me that error when I try to check the result.

Thanks for your help.

-Thomas