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Accessing elements in JSON array

I haven't worked much with JSON and I'm using Google Maps Distance Matrix API to get generate some data I'd like to use.
I'd like to pull the number 14147 from duration.
{
"destination_addresses" : [ "Washington, DC, USA" ],
"origin_addresses" : [ "New York, NY, USA" ],
"rows" : [
{
"elements" : [
{
"distance" : {
"text" : "226 mi",
"value" : 364089
},
"duration" : {
"text" : "3 hours 56 mins",
"value" : 14147
},
"status" : "OK"
}
]
}
],
"status" : "OK"
}
I've tried a few different things, here's what I tried last (data is just the array above):
String data = getOutputAsText(geoService);
JSONObject json = new JSONObject(data);
String duration = json.getJSONArray("rows").getString("duration");
Here's the console output:
org.json.JSONException: JSONObject["duration"] not found
I made sure to look around before posting but I haven't found anything that has been able to help me with this particular problem.
I want to pass the value from duration to my own web service, which I can do, I just don't know how to extract the value. Thank you in advance!

First of all, please have a look at this answer. Using org.json you can do smth. like that:
JSONObject obj = new JSONObject("Content of your string here");
JSONArray rows = obj.getJSONArray("rows");
for (int i = 0; i < rows.length(); i++) {
JSONArray elements = rows.getJSONObject(i).getJSONArray("elements");
for(int j = 0; j < elements.length(); j++) {
JSONObject element = elements.getJSONObject(j);
JSONObject duration = element.getJSONObject("duration");
int value = duration.getInt("value");
}
}
The code above has produced following output using your json String: 14147
P.S. You can make use of a library you wish. This one used here was purposed for the demonstrating.

Dynamic way to access JSON nested values in Java

I have this JSON object:
{
"maindrawer":
{
"enabled": true,
"actions":
[
{
"type": "Section",
"title": "Section 1"
},
{
"id": 1,
"type": "Primary",
"title": "Title 1",
"badge":
{
"enabled": false,
"value": 0,
"textColor": "#000000",
"badgeColor": "#ff0990"
},
"subActions":
[
{
"id": 1,
"type": "Primary",
"title": "Sub Title 1"
}
]
}
]
}
}
This is the code I'm using to access the badge -> textColor value:
public void loadJSONFromRaw(Context context, int id)
{
json = null;
try
{
//read and return json sting
InputStream is = context.getResources().openRawResource(id);
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
json = new String(buffer, "UTF-8");
//convert json to object
Type type = new TypeToken<Map<String, Object>>() {}.getType();
Map<String, Object> data = new Gson().fromJson(json, type);
//access maindrawer property
Map<String, Object> maindrawer = (Map<String, Object>)data.get("maindrawer");
//access actions list
List<Object> actions = (List<Object>)maindrawer.get("actions");
//return first item in the list
Map<String, Object> action = (Map<String, Object>) actions.get(1);
//return badge object
Map<String, String> badge = (Map<String, String>) action.get("badge");
//access badge -> textColor value
String textColor = badge.get("textColor");
}
catch (IOException e)
{
e.printStackTrace();
}
}
Is there a better/faster or more dynamic way to access JSON nested properties using java/android? I'm using Gson library for this task and don't mind to switch to any other solution to make it easier as this is too much of code to write just to access a single variable.
Ideally, I'm looking for something like:
String textColor = data.get("maindrawer").get("actions").get(1).get("badge").get("textColor");
Also I'm not very interested in using POJO for now.
Lastly, I'm still new to Java so I'm probably missing something here or maybe there are some limitations? anyways thanks for you help!!

Found what I need using JsonPath library. It looks like it does similar to what I need. Here's a sample code I found:
String textColor = JsonPath.parse(json).read("$.maindrawer.actions[1].badge.textColor");
Very clean and straightforward. Hopes this will save someone else's time as well.

Since you are accessing json file locally, it means you know its structure.
So instead of using -
Map<String, Object> data = new Gson().fromJson(json, type);
You can use something like this-
Map<String, MainDrawer> data = new Gson().fromJson(json, type);
where MainDrawer is a class with member variables - enabled, actions and array of another type.
That would make easier to fetch your values like using -
mainDrawer.isEnabled()

Here are two solutions without importing a new library.
Write a simple path parser:
String textColor = (String)parse(data, "maindrawer", "actions", 1, "badge", "textColor");
//...
static Object parse(Object root, Object... params) {
Object current = root;
for (Object p : params) {
if (p instanceof Number) {
current = ((List<?>)current).get(((Number)p).intValue());
} else {
current = ((Map<?,?>)current).get(p.toString());
}
}
return current;
}
Or parse and walk through Gson's JsonElement:
JsonElement root = new Gson().fromJson(json, JsonElement.class);
String textColor = root
.getAsJsonObject().get("maindrawer")
.getAsJsonObject().get("actions")
.getAsJsonArray().get(1)
.getAsJsonObject().get("badge")
.getAsJsonObject().get("textColor")
.getAsString();

You can also do this with BSON using a single line query. You have to cast the object to the type as you go down into Nested JSON objects.
//import java.util.ArrayList;
//import org.bson.Document;
Document root = Document.parse("{ \"maindrawer\" : { \"enabled\" : true, \"actions\" : [{ \"type\" : \"Section\", \"title\" : \"Section 1\" }, { \"id\" : 1, \"type\" : \"Primary\", \"title\" : \"Title 1\", \"badge\" : { \"enabled\" : false, \"value\" : 0, \"textColor\" : \"#000000\", \"badgeColor\" : \"#ff0990\" }, \"subActions\" : [{ \"id\" : 1, \"type\" : \"Primary\", \"title\" : \"Sub Title 1\" }] }] } }");
System.out.println(((String)((Document)((Document)((ArrayList)((Document)root.get("maindrawer")).get("actions")).get(1)).get("badge")).get("textColor")));

Parse a complex JSON result

I have a json (result) like the below , i need the value of Key "extra", that is "contact office".
I tried the below code, but it did not work, can you help?
JSONArray jsonArray = new JSONArray(result.toString().trim());
JSONObject json = jsonArray.getJSONObject(0).getJSONObject("student").getJSONArray("department").getJSONObject(0).getJSONObject("classes");
String val=json.getString("extra");
// JSON Example
{
"student": [
{
"department" : [
{
"classes" : [
{
"grade" : "A",
"fine" : "No"
},
{
"grade" : "B",
"fine" : "Yes",
"extra" : "contact office"
},
{
"grade" : "C",
"fine" : "NA"
}
],
}
],
}
],
}

You mixed up JSONArray and JSONObject a few times, not sure exactly what I had to change but the following will work:
JSONObject jsonObject = new JSONObject(result.toString().trim());
JSONArray jsonArray = jsonObject
.getJSONArray("student").getJSONObject(0).getJSONArray("department").getJSONObject(0)
.getJSONArray("classes");
String val = jsonArray.getJSONObject(1).getString("extra");

Is this a full sample? If so it doesn't start out as an array. Student is and object not an array. If it is just a sample of one item in the array then you're okay.
The second thing I noticed is: getJSONObject("classes"). Classes is an array not an object, this won't work.

Would you like to consider using JsonPath. You could do something like this -
String[] extraValues = JsonPath.read(json, "$.student[0].department[0].classes[*].extra");

Android: Dynamically Get JSON Array Key Name From JSON

I have a json link, if we open it I get a following result
{
"Status": "Success",
"All_Details": [{
"Types": "0",
"TotalPoints": "0",
"ExpiringToday": 0
}],
"First": [{
"id": "0",
"ImagePath": "http://first.example.png"
}],
"Second": [{
"id": "2",
"ImagePath": "http://second.example.png"
}],
"Third": [{
"id": "3",
"ImagePath": "http://third.example.png"
}],
}
What I need is, I want to dynamically get all the key names like status, All_details, First etc.
And I also want to get the data inside the All_details and First Array.
I used following method
#Override
public void onResponse(JSONObject response) throws JSONException {
VolleyLog.d(TAG, "Home Central OnResponse: " + response);
String statusStr = response.getString("Status");
Log.d(TAG, "Status: " + statusStr);
if (statusStr.equalsIgnoreCase("Success")) {
Iterator iterator = response.keys();
while (iterator.hasNext()) {
String key = (String)iterator.next();
}
}
}
I get all the key names in get stored in the String key. But I am unable to open get the values inside the JSON array, for eg. I need to get the values inside first and second array using the String(Key). How can I do that.???

First, to get the keynames, you can easily iterate through the JSONObject itself as mentioned here:
Iterator<?> keys = response.keys();
while( keys.hasNext() ) {
String key = (String)keys.next();
if ( response.get(key) instanceof JSONObject ) {
System.out.println(key); // do whatever you want with it
}
}
Then, to get the values of the array:
JSONArray arr = response.getJSONArray(key);
JSONObject element;
for(int i = 0; i < arr.length(); i++){
element = arr.getJSONObject(i); // which for example will be Types,TotalPoints,ExpiringToday in the case of the first array(All_Details)
}

If you want to get the JSON array from the response JSONObject you can use the JSONArray class. JSONObject has a method to get a JSONArray: getJSONArray(String). Remember to catch the JSONException when trying this. This exception will be thrown if there is no key for example.
Your code could look like this (only the while loop):
while (iterator.hasNext()) {
String key = (String)iterator.next();
try {
JSONArray array = response.getJSONArray(key);
// do some stuff with the array content
} catch(JSONException e) {
// handle the exception.
}
}
You can get the values from the array with the methods of JSONArray (see the documentation)

Something like this will allow you to iterate on array and individual fields once you have extracted the keys using what you have done. Instead of "Types" use the key variable you will create before this.
JSONArray allDetails = response.getJsonArray("All_Details")
for (int i = 0 ; i < allDetails.length(); i++) {
JSONObject allDetail = allDetails.getJSONObject(i);
allDetails.getString("Types");
}

First of all I want to inform you that it's not a valid JSON. Remove the last Comma (,) to make it valid.
Then you can Iterate like here
JSONArray myKeys = response.names();

Try this one
Iterator keys = jsonObject.keys();
while (keys.hasNext()) {
try {
String dynamicKey = (String) keys.next();//Your dynamic key
JSONObject item = jsonObject.getJSONObject(dynamicKey);//Your json object for that dynamic key
} catch (JSONException e) {
e.printStackTrace();
}
}

JSON Parsing Nested Array Objects

Using Simple-JSON on the following JSON formatted file, I'm having a lot of trouble understanding how to access the objects within the array under "name".
JSON File:
[
{
"name":{
"firstName": "Developer",
"lastName": "D"
},
"id": 00,
"permissionLevel": 3,
"password": 12345
},
{
"name":{
"firstName": "Bob",
"lastName": "Smith"
},
"id": 01,
"permissionLevel": 2,
"password": 23456
}
]
I'm able to obtain the information for all of the other contents because they're not located in a nested array; However, when I attempt to retrieve the objects under "name", all that is output is the String found in the JSON file.
Current code:
String[] searchData = {
"name",
"firstName",
"lastName",
"id",
"permissionLevel",
"password"
};
jsonArray = (JSONArray)new JSONParser().parse(s);
for(int i = 0; i < jsonArray.size(); i++){
JSONObject jo = (JSONObject)jsonArray.get(i);
for(int j = 0; j < searchData.length; j++){
System.out.println(
searchData[j] + ": " + jo.get(searchData[j]));
}
}
Output:
name: [{"firstName":"Developer","lastName":"D"}]
firstName: null
lastName: null
id: 0
permissionLevel: 3
password: 12345
name: [{"firstName":"Bob","lastName":"Smith"}]
firstName: null
lastName: null
id: 1
permissionLevel: 2
password: 23456
As you can see, "name" outputs a String from the JSON file, and not each individual value.
In the end, I need to write a universal code that can accept new "searchData" tags for each file that's input.
Might someone be able to direct me how to obtain objects held
within nested arrays?
Or perhaps I need to use a different Library? If so, which one is the most efficient for Java? I'm not programming for Android, and I continue to find Library suggestions for Android, constantly.
My apologies if this post is a dupe, but no other posts are aiding me.

You should get your firstname and lastname, like:
jo.get("name").get("firstname");
jo.get("name").get("lastname");

To get the objects held within nested arrays/objects, you will have to write a recursive method and flatten the structure into a map. Below example shows the same:
public static void main(String args[]) throws ParseException {
Object object = new JSONParser().parse("[ { \"name\":{ \"firstName\": \"Developer\", \"lastName\": \"D\" }, \"id\": 00, \"permissionLevel\": 3, \"password\": 12345 }, { \"name\":{ \"firstName\": \"Bob\", \"lastName\": \"Smith\" }, \"id\":01, \"permissionLevel\": 2, \"password\": 23456 }]");
Map<String, Object> pairs = new HashMap<>();
addValues(object, pairs);
System.out.println(pairs);
}
public static void addValues(Object object, Map<String, Object> pairs){
if(object instanceof JSONObject){
JSONObject jsonObject = (JSONObject) object;
for(String key : jsonObject.keySet()){
if(jsonObject.get(key) instanceof JSONObject || jsonObject.get(key) instanceof JSONArray){
addValues(jsonObject.get(key), pairs);
}else{
pairs.put(key, jsonObject.get(key));
}
}
}else if(object instanceof JSONArray){
JSONArray jsonArray = (JSONArray)object;
for(Object element : jsonArray){
addValues(element, pairs);
}
}
}
You can tweak this method to have keys like name.firstname or name.lastname depending on requirements.

I understand that you want the searchData tags to be taken into consideration while parsing the JSON. I would suggest using Google Gson for this case.
You can write a POJO which return the ArrayList<User> for your JSON.
Refer this article on how use Google Gson