Java

JSON Paths

See more JSON Examples

Demonstrates using "Chilkat JSON Paths" to access parts of a JSON document, or to iterate over parts.

This example uses the following JSON document:

{
    "nestedArray" : [
			[
				[1,2,3],
				[4,5,6],
				[7,8,9,10]
			],
			[
				[11,12,13],
				[14,15,16],
				[17,18,19,20]
			],
			[
				[21,22,23],
				[24,25,26],
				[27,28,29,30],
				[31,32,33,34,35,36]
			]
		],

	"nestedObject" : {
		"aaa" : {
			"bb1" : {
				"cc1" : "c1Value",
				"cc2" : "c2Value",
				"cc3" : "c3Value"
			},
			"bb2" : {
				"dd1" : "d1Value",
				"dd2" : "d2Value",
				"dd3" : "d3Value"
			}
		}
	},

	"mixture" : {
		"arrayA" : [  
			{ "fruit": "apple", "animal": "horse", "job": "fireman", "colors": ["red","blue","green"] },
			{ "fruit": "pear", "animal": "plankton", "job": "waiter", "colors": ["yellow","orange","purple"] },
			{ "fruit": "kiwi", "animal": "echidna", "job": "astronaut", "colors": ["magenta","tan","pink"] }
			]
	},


        "name.with.dots" : { "grain" : "oats" }

	
}

Chilkat2 Java

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

public class ChilkatExample {

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

        // Assume the file contains the data as shown above..
        try {
            json.loadFile("qa_data/json/pathSample.json");
        } catch (ChilkatException e) {
            System.out.println(e.getLastErrorText());
            return;
        }

        // First, let's get the value of "cc1"
        // The path to this value is: nestedObject.aaa.bb1.cc1
        System.out.println(json.stringOf("nestedObject.aaa.bb1.cc1"));

        // Now let's get number 18 from the nestedArray.
        // It is located at nestedArray[1][2][1]
        // (remember: Indexing is 0-based)
        System.out.println("This should be 18: " + json.intOf("nestedArray[1][2][1]"));

        // We can do the same thing in a more roundabout way using the
        // I, J, and K properties.  (The I,J,K properties will be convenient
        // for iterating over arrays, as we'll see later.)
        json.setI(1);
        json.setJ(2);
        json.setK(1);
        System.out.println("This should be 18: " + json.intOf("nestedArray[i][j][k]"));

        // Let's iterate over the array containing the numbers 17, 18, 19, 20.
        // First, use the SizeOfArray method to get the array size:
        int sz = json.sizeOfArray("nestedArray[1][2]");
        // The size should be 4.
        System.out.println("size of array = " + sz + " (should equal 4)");

        // Now iterate...
        for (int i = 0; i < sz; i++) {
            json.setI(i);
            System.out.println(json.intOf("nestedArray[1][2][i]"));
        }

        // Let's use a triple-nested loop to iterate over the nestedArray:

        // szI should equal 1.
        int szI = json.sizeOfArray("nestedArray");
        for (int i = 0; i < szI; i++) {
            json.setI(i);

            int szJ = json.sizeOfArray("nestedArray[i]");
            for (int j = 0; j < szJ; j++) {
                json.setJ(j);

                int szK = json.sizeOfArray("nestedArray[i][j]");
                for (int k = 0; k < szK; k++) {
                    json.setK(k);

                    System.out.println(json.intOf("nestedArray[i][j][k]"));
                }
            }
        }

        // Now let's examine how to navigate to JSON objects contained within JSON arrays.
        // This line of code gets the value "kiwi" contained within "mixture"
        System.out.println(json.stringOf("mixture.arrayA[2].fruit"));

        // This line of code gets the color "yellow"
        System.out.println(json.stringOf("mixture.arrayA[1].colors[0]"));

        // Getting an object at a path:
        // This gets the 2nd object in "arrayA"

        JsonObject obj2 = new JsonObject();
        json.objectOf2("mixture.arrayA[1]", obj2);

        // This object's "animal" should be "plankton"
        System.out.println(obj2.stringOf("animal"));

        // Note that paths are relative to the object, not the absolute root of the JSON document.
        // Starting from obj2, "purple" is at "colors[2]"
        System.out.println(obj2.stringOf("colors[2]"));

        // Getting an array at a path:
        // This gets the array containing the colors red, green, blue:

        JsonArray arr1 = new JsonArray();
        json.arrayOf2("mixture.arrayA[0].colors", arr1);

        int szArr1 = arr1.getSize();
        for (int i = 0; i < szArr1; i++) {
            System.out.println(i + ": " + arr1.stringAt(i));
        }

        // The Chilkat JSON path uses ".", "[", and "]" chars for separators.  When a name
        // contains one of these chars, use double-quotes in the path:
        System.out.println(json.stringOf("\"name.with.dots\".grain"));
    }
}