Parsing JSON with PeopleCode

A lot of web services return results in JSON format rather than XML. Is it possible to parse JSON in PeopleCode? Can you consume JSON web services uisng PeopleCode? Absolutely. My first attempt at parsing JSON in PeopleCode used eval and the Rhino JavaScript scripting engine as documented in my post Scripting PeopleSoft. Because the Bean Scripting Framework's BSFEngine.eval method returns a java.lang.Object, I was left in a state of painful Java Reflection (executing each call using Java Reflection). Looking over the json.org website, I took note of the collection of Java JSON parsers. After choosing the org.json parser. I again found myself having to deal with the pain of Java Reflection (and, most definitely, I was left wishing PeopleCode had a JavaCast function). Rather than deal with the Java reflection required to create an instance of a JSONObject or JSONArray, I chose an easier route: write a helper class to construct JSON objects. Here is the source:

package yourcompany.json;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

public class ParseHelper {
    private ParseHelper() {
    }

    public static JSONObject objectFromString(String json) throws JSONException {
        return new JSONObject(json);
    }

    public static JSONArray arrayFromString(String json) throws JSONException {
        return new JSONArray(json);
    }
}

If my JSON looks like

{
    "EMPLID": "E1234",
    "NAME": "Marion,Jim",
    "DIRECTS": [
        {
            "EMPLID": "E5678",
            "NAME": "Doe,John" 
        },
        {
            "EMPLID": "E2468",
            "NAME": "Doe,Jane" 
        } 
    ]
}

Then I can enumerate the directs array using PeopleCode like:

Local string &json_data = "my JSON string...";

REM ** use static helper class to avoid ugly Java reflection;
Local JavaObject &json =  GetJavaClass("yourcompany.json.ParseHelper").objectFromString(&json_data);
Local JavaObject &directsArr = &json.getJSONArray("DIRECTS");
Local number &length = &directsArr.length();
Local number &directsIdx = 0;

For &directsIdx = 0 To &length - 1
   Local JavaObject &direct = &directsArr.getJSONObject(&directsIdx);
   &logger.debug("DIRECTS [" | &directsIdx | "] " | &direct.get("NAME").toString());
End-For;