How to Get all JSON Paths from JSON

How to Get all jsonpaths from JSON: In this tutorial will see code to get all JSON paths from a JSON object.

A JSON path expression is used to extract the value from the JSON object.

Add below dependency to your project.

<dependency>
   <groupId>org.json</groupId>
   <artifactId>json</artifactId>
   <version>20160212</version>
</dependency>

Then Create Class with JSONPathmain class name then use below code.

import org.json.JSONException;

public class JSONPathmain {

	public static void main(String[] args) throws JSONException {
		// TODO Auto-generated method stub
		String json  ="{ \"store\": {\"book\": [ { \"category\": \"reference\",\"author\": \"Nigel Rees\",\"title\": \"Sayings of the Century\",\"price\": 8.95},{ \"category\": \"fiction\",\"author\": \"Evelyn Waugh\",\"title\": \"Sword of Honour\",\"price\": 12.99},{ \"category\": \"fiction\",\"author\": \"Herman Melville\",\"title\": \"Moby Dick\",\"isbn\": \"0-553-21311-3\",\"price\": 8.99},{ \"category\": \"fiction\",\"author\": \"J. R. R. Tolkien\",\"title\": \"The Lord of the Rings\",\"isbn\": \"0-395-19395-8\",\"price\": 22.99}],\"bicycle\": {\"color\": \"red\",\"price\": 19.95}}}";
		JsonParser parser = new JsonParser(json);
		System.out.println(parser.getPathList());
	}

}

Next, Create Another class with name JsonParser  and use below code

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

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

public class JsonParser {

    private List<String> pathList;
    private String json;

    public JsonParser(String json) throws JSONException {
        this.json = json;
        this.pathList = new ArrayList<String>();
        setJsonPaths(json);
    }

    public List<String> getPathList() {
        return this.pathList;
    }

    private void setJsonPaths(String json) throws JSONException {
        this.pathList = new ArrayList<String>();
        JSONObject object = new JSONObject(json);
        String jsonPath = "$";
        if(json != JSONObject.NULL) {
            readObject(object, jsonPath);
        }   
    }

    private void readObject(JSONObject object, String jsonPath) throws JSONException {
        Iterator<String> keysItr = object.keys();
        String parentPath = jsonPath;
        while(keysItr.hasNext()) {
            String key = keysItr.next();
            Object value = object.get(key);
            jsonPath = parentPath + "." + key;

            if(value instanceof JSONArray) {            
                readArray((JSONArray) value, jsonPath);
            }
            else if(value instanceof JSONObject) {
                readObject((JSONObject) value, jsonPath);
            } else { // is a value
                this.pathList.add(jsonPath);    
            }          
        }  
    }

    private void readArray(JSONArray array, String jsonPath) throws JSONException {      
        String parentPath = jsonPath;
        for(int i = 0; i < array.length(); i++) {
            Object value = array.get(i);        
            jsonPath = parentPath + "[" + i + "]";

            if(value instanceof JSONArray) {
                readArray((JSONArray) value, jsonPath);
            } else if(value instanceof JSONObject) {                
                readObject((JSONObject) value, jsonPath);
            } else { // is a value
                this.pathList.add(jsonPath);
            }       
        }
    }

}

Change your JSON Object in JSONPathmain class and run java class to see the output.

Also Read: How to Create JSON Web Token (JWT) using Java