Hi.  I've just started getting into processing and am really enjoying it -- great work!  

I'm working on a project that uses data in JSON format  (www.json.org).  It took me a while to get it going in processing, so I thought I'd post what I did here.  If there's a better way (which undoubtedly there is!), please let me know.

Andrew Odewahn

--
Here are the steps I took (on Windows):

1.  Download http://www.json.org/java/json.zip from json.org.  Save it in a some directory, which I'll call %DOWNLOAD_HOME%.

2.  Unzip it.  Be sure you preserve the archive's directory structure (/org/json/) when you unzip the file.  

3.  Change directory into %DOWNLOAD_HOME%\org\json

4.  Compile the files by running “javac *.java”.  At least, this worked for me.  There is no build.xml or anything, and it just seemed to compile into classes nicely.

5.  CD back into %DOWNLOAD_HOME%

6.  Create a jar file called json.jar.  The syntax is something like:

     jar -cvf json.jar org\json\*.class

7.  To use the library, use "Sketh -> Add File" to add the json.jar file into your project.  

Here are links to a sample JSON data file (basic time series data on Ruby and Python) and code to process it:

http://data.oreilly.com/~aodewahn/processing_json/json_data_example.js

http://data.oreilly.com/~aodewahn/processing_json/process_json.txt

cool, thanks for posting.

a few notes about your code that can be simplified too:

1) the pullJSON() method can be simplified significantly:
Code:

JSONObject pullJSON(String targetURL) {
  String[] lines = loadStrings(targetURL);
  return new JSONObject(join(lines, ""));
}
 

2) and since you're connecting points, beginShape() is easier to use than line(), and you won't have to keep track of the previous points:
Code:

noFill();
beginShape();
float tt = 126 * i+1/4.0;
stroke(tt);
for (int j=0; j < d.length(); j++) {
	     JSONObject obs = d.getJSONObject(j);
	     float y = (float) obs.getDouble("value");
	     float x = (float) obs.getDouble("pctOfRange");
	     //Set the colors and draw the lines
	     float x1 = x * width;
	     float y1 = (1-pctOfRange(y))*height;
	     vertex(x1, y1);
}
endShape();
 

3) you can also use map() for the y1 value, instead of pctOfRange():
Code:

	     float y1 = map(y, minY, maxY, height, 0);
 

thanks again!

(edited for intelligibility)

The CDL class in this JSON package incidentally makes it easy to import and use comma-delimited data. Here's a variant of my example above:

Quote:

Thank you guys for the information on JSON. It just saved me a lot of work and research!

Hi,

I´m trying unsuccesfully to implement json on mac osx 10.5. It returns the following error:

"The type org.json.JSONTokener cannot be resolved. It is indirectly referenced from required .class files"

Code:

 

void setup() {
  try {
    URL url = new URL("http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=Hamburg%20Berlin");
    URLConnection connection = url.openConnection();
    connection.addRequestProperty("Referer", "http://bliz.btk-fh.de");

    String line;
    StringBuilder builder = new StringBuilder();
    BufferedReader reader = new BufferedReader(new InputStreamReader(connection.getInputStream()));
    while((line = reader.readLine()) != null) {
	builder.append(line);
    }

    JSONObject json = new JSONObject(builder.toString());
    //println(json + "\n\n");
    int resultCount = json.getJSONObject("responseData").getJSONObject("cursor").getInt("estimatedResultCount");
    println("resultCount=" + resultCount);
  }
  catch (Exception e) {
    println("Error: " + e.toString());
  }
}

 

I think the error has something to do with my self-compiled json.jar. Perhaps someone working on mac osx could send me a link to their working version?

Best regards,
Chris

mfg: the following code works for me

// Functions to retrieve data from google and yahoo
void getGoogleData()
{
 try {
       // Send data
       URL url = new URL("http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=link:www.thename.com...;
       //URL url = new URL("http","ajax.googleapis.com","");
       
       URLConnection u = url.openConnection();
       u.setDoOutput(true);
       u.setRequestProperty("Referer", "http://www.my-ajax-site.com");
       
       BufferedReader in = new BufferedReader(new InputStreamReader(url.openStream()));
       
       String inputLine;
       StringBuilder builder = new StringBuilder();
 

while ((inputLine = in.readLine()) != null)

   builder.append(inputLine);


in.close();
     
       print(builder.toString());
       
       JSONObject json = new JSONObject(builder.toString());
       
       int resultCount = json.getJSONObject("responseData").getJSONObject("cursor").getInt("estimatedResu
ltCount");
       println("resultCount=" + resultCount);


 } catch (MalformedURLException e) {
    println("MalformedURLException");
    println(e);
 } catch (IOException e) {               // openConnection() failed
   println("IOException");
   println(e);
 } catch (JSONException e) {               // openConnection() failed
   println("JSONException");
   println(e);
 }
}

steve, it should work out of the box, I don't see a Json library using native code...
Reporting what error you have might help...

This thread was quite helpful for getting started, but I'm currently struggling to pull the data from a JSON feed of the following format:

Code:

{
"group": {"slug": "recent-activity", "entries": [
{
"unique_id": "http://delicious.com/url/b91962bd93dbb86863323b410e9a1a60#cmeinke", 
"title": "The Nature of Code. Chapter 1: Vectors", 
"raw_content": "Draft chapter one of upcoming book "The Nature of Code" by Daniel Shiffman", 
"url": "http://www.scribd.com/doc/15888334/The-Nature-of-Code-Chapter-1-Vectors", 
"raw_title": "The Nature of Code. Chapter 1: Vectors", 
"feed_id": 693, 
"content": "Draft chapter one of upcoming book "The Nature of Code" by Daniel Shiffman", 
"published_at": "2009-06-03T10:59:38Z"
}, ...
 

source: http://feedstitch.com/cmeinke/recent-activity.json



Code:

public class JsonTest01 extends PApplet{

	public void setup(){

		try {
		 JSONObject activityData = new JSONObject(join(loadStrings("recent-activity.json"), ""));
		 JSONArray entries = activityData.getJSONArray("entries");
		 for (int i = 0; i < entries.length(); i++) {
		   JSONObject entry = entries.getJSONObject(i);
		   println("Entry content:" + entry.getInt("feed_id") + " : " + entry.getString("title"));
		 }
		}
		catch (JSONException e) {
		 println (e.toString());
		}
	
	}

}
 

I'm currently trying to fetch the data with getJSONArray() but getting the following error:

Quote:


I broke down the structure of the JSON feed provided by FeedStitch and realized that if I strip it down to the "entries" array everything is working as expected.

Code:

// original structure
{
"group": {
	"slug": "YourFeedSlug", 

	"entries": [
		{	
		"unique_id": "", 
		"title": "", "raw_content": "", 
		"url": "", 
		"raw_title": "", 
		"feed_id": int, 
		"content": "", 
		"published_at": ""
		}, ...
	], 

	"title": "YourFeedTitle", "description": null
	}
}

// stripped down to "entries" array

{
	"entries": [
		{	
		"unique_id": "", 
		"title": "", "raw_content": "", 
		...
		}, 
	], 
 

Now I'm looking for a way to get around the group and meta information (slug, title, ...) to keep things dynamic. Any ideas or suggestions?

Edit:

Finally got the object stucture of JSON. Jer's post: Processing, JSON & The New York Times helped understanding how to fetch objects located within other objects.

Sorry fro spamming this thread. :|