Java

Get the Index of a JSON Member

See more JSON Examples

This example demonstrates how to get the index of a given member by name.

{
  "name": "donut",
  "image":
    {
    "fname": "donut.jpg",
    "w": 200,
    "h": 200
    },
  "thumbnail":
    {
    "fname": "donutThumb.jpg",
    "w": 32,
    "h": 32
    }
}

Chilkat2 Java

import com.chilkatsoft.chilkat2.ChilkatException;
import com.chilkatsoft.chilkat2.JsonObject;

public class ChilkatExample {

    public static void main(String[] args) {
        JsonObject json = new JsonObject();

        // This is the above JSON with whitespace chars removed (SPACE, TAB, CR, and LF chars).
        // The presence of whitespace chars for pretty-printing makes no difference to the Load
        // method.
        String jsonStr = "{\"name\": \"donut\",\"image\":{\"fname\": \"donut.jpg\",\"w\": 200,\"h\": 200},\"thumbnail\":{\"fname\": \"donutThumb.jpg\",\"w\": 32,\"h\": 32}}";

        try {
            json.load(jsonStr);
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // The top-level JSON object has three members: name, image, and thumbnail.
        int nameIndex = json.indexOf("name");
        // The index of the "name" member is 0.
        System.out.println("nameIndex = " + nameIndex);

        int thumbIndex = json.indexOf("thumbnail");
        // The index of the "thumbnail" member is 2.
        System.out.println("thumbIndex = " + thumbIndex);

        // The "fname" member is NOT a direct member of the top-level JSON object.
        // It is a member of a nested object.  If we try to get the index of this
        // member using the top-level JSON object, it is not found (and returns -1).
        int fnameIndex = json.indexOf("fname");
        // The fnameIndex is -1 (not found).  This is correct.
        System.out.println("fnameIndex = " + fnameIndex);

        // Get the "image" object.
        JsonObject imageObj = new JsonObject();
        json.objectOf2("image", imageObj);

        // Now we can get the index of the "fname" object, because it is a direct
        // member of the "image" object:
        fnameIndex = imageObj.indexOf("fname");
        System.out.println("fnameIndex = " + fnameIndex);
    }
}