I'm fairly new to processing and programming in general, and I'm
having some trouble in getting a program to work ( no surprises
there, I suppose. )

The bit of code I'm working on works as it's supposed to: loading
random image urls from google images to strings and using
loadimage to put them in the application pixels buffer.

The damn thing throws ArrayIndexOutOfBoundsException : 1
( jawa.awt.image.PixelGrabber.setPixels )  at me since I put
the loadImage() inside draw.

But for the program to work at all I need to use it, or something
similar inside draw. Any way to around this? Making connections
with the client object and getting the size of the .jpg:s to check when
they're done? I checked dev.processing.org for solutions, but couldn't
really find anything. ( Because I'm new. I also hope this is the right
forum to ask this. )

Suggestions? Help? Help!

Well, here's the code, rather sloppy but...

At this point it just finds random images and
puts them on screen. Haven't added the bits
of code that would modify them yet.


Code:

import processing.net.*; 
import java.util.regex.*;
import java.io.*;

private static Pattern pattern;
private static Matcher matcher;

int kuvanro = 0;
String kuva = "0";
String kuvatus;
boolean toimii = false;  
Client google; 
String myHost = "images.google.fi";
String google1 = "/images?hl=fi&q=dsc0";
String google2 = ".jpg%20filetype%3Ajpg&btnG=Google-haku&sa=N&tab=wi"; 
String google3;
String google4;
int check = 1;
boolean check2 = false;
  
PImage vkuva;


void setup() { 
  size(800, 600); 
  background(50);
  loadPixels();
  hae();
} 
 

void hae() {

  if(check == 1){
  kuvanro = int(random(0, 9999));
  if( kuvanro <= 9 ){
    kuva = "000" + char(kuvanro);
  }
  if( kuvanro <= 99 ){
    kuva = "00" + str(kuvanro);
  }
  if( kuvanro <= 999 ){
    kuva = "0" + str(kuvanro);
  }
  if( kuvanro >= 1000 ){
    kuva = str(kuvanro);
  }
   
  google3 = google1+kuva+google2;
  google = new Client(this, myHost, 80); 
  println("trying to fetch from "+myHost); 
  // Send the HTTP GET request: 
  google.write("GET "+google3+" HTTP/1.1\n"); 
  google.write("HOST: "+myHost+"\n\n");
  check = 0;
  check2 = true;
  google4 = "0";
  
  }
  
  while(check2){    
    if(google.available()>1){
	google4 += google.readString();
    }
    
    if(google.available()<1 && google4.length() > 20000){	    
	  check2 = false;	
    }    
	    
  }  

  pattern = Pattern.compile("<img src=/images.*?>");
  matcher = pattern.matcher(google4);
  
  while(matcher.find()){
	toimii = false;
	kuvatus = matcher.group().substring(36, matcher.group().lastIndexOf(119)-1);
	println("getting an image from: "+kuvatus.substring(0, kuvatus.indexOf(47)));
	try{
	  vkuva = loadImage("http://"+kuvatus);
	  toimii = true;
	} catch(RuntimeException e) {
	  println("failed to load image from: "+kuvatus.substring(0, kuvatus.indexOf(47)));	  
	}
  
	if(toimii){
	  println("displaying image: "+"http://"+kuvatus);
	  image(vkuva, 0, 0);
	}
  }
  
  check = 1;
  google.stop();
  
}  

try printing the url that you're trying to grab, and then go see if that's a valid url in the browser.

also, loadImage() no longer throws a RuntimeException (it'll just reutnr null) if it doesn't load.

Hi Lauri,

I modified a bit your code, and it works now at least on my computer with Processing 0095. I tweaked mostly other parts of the code and moved the image drawing to draw()-method.

-Janne

import java.util.regex.*;

private static Matcher matcher;

String searchStart = "http://images.google.fi/images?hl=fi&q=dsc0";
String searchEnd   = ".jpg%20filetype%3Ajpg&btnG=Google-haku&sa=N&tab=wi";  

void setup() {  
 size(800, 600);  
 background(50);
 fetchLinks();
}

void draw() {
 drawNextImage();
}

void fetchLinks() {
 NumberFormat formatter = new DecimalFormat("0000");
 String imageName = formatter.format(random(0, 9999));
 String pageContent;

 try {
   URL url = new URL(searchStart+imageName+searchEnd);
   pageContent = webFetch(url);
 } catch(Exception e) {
   println("URL could not be formed: "+e);
   return;
 }
 
 Pattern pattern = Pattern.compile("<img src=/images.*?>");
 matcher = pattern.matcher(pageContent);
}


void drawNextImage() {
 matcher.find();
 String tmpUrl = matcher.group();
 String imageUrl = "http://"+tmpUrl.substring(36, matcher.group().lastIndexOf(119)-1);
   
 println("fetching image: "+imageUrl);
 try {
   PImage currImage = loadImage(imageUrl);
   println("displaying image: "+imageUrl);
   image(currImage,0,0);
 } catch(RuntimeException e) {
   println("error fetching url: "+imageUrl);
 }
}

private static String webFetch(URL url) throws Exception {
 try {
   URLConnection con = url.openConnection();
   con.setRequestProperty( "User-Agent", "Mozilla/4.0 (compatible; MSIE 5.21; Mac_PowerPC)" );
   InputStream content = con.getInputStream();
   StringWriter writer = new StringWriter();

   for(int c = content.read(); c!= -1; c = content.read()) {
     writer.write(c);
   }
   return writer.toString();
 } catch( Exception e ) {
   throw e;
 }
}