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I have json object with contain a list of other object and want to convert it in HashMap in java

this is the json , I wanted to convert to HashMap
`
ob = "{
"arrival": "RONGO",
"segmentPrices": [
{
"id": "",
"localId": "",
"localCode": "",
"localDesignation": "",
"amounts": [
{
"value": 950,
"currency": "Ksh"
}
]
}
]
} ";
Gson gson = new Gson();
HashMap<String,Object> result = new ObjectMapper().readValue(gson.toJson(ob), HashMap.class);
`
but i can't access to amounts object,
the value of result.get("amounts") is null
somebody can please help me for this ?

Using gson 2.0 here is what you can parse your json as HashMap and access amounts array:
public static void main(String[] args) throws IOException {
Gson gson = new Gson();
HashMap<String, Object> map = gson.fromJson(new FileReader("test.json"), HashMap.class);
ArrayList<Object> prices = (ArrayList<Object>) map.get("segmentPrices");
prices.forEach(p -> {
if (p instanceof LinkedHashMap) {
System.out.println(((LinkedHashMap)p).get("amounts"));
}
});
}
test.json file contains your json.
Output is:
[{value=950.0, currency=Ksh}]
You can access the parameters inside the object in the amount array as below:
public static void main(String[] args) throws IOException {
Gson gson = new Gson();
HashMap<String, Object> map = gson.fromJson(new FileReader("test.json"), HashMap.class);
ArrayList<Object> prices = (ArrayList<Object>) map.get("segmentPrices");
prices.forEach(p -> {
if (p instanceof LinkedHashMap) {
ArrayList<Object> amounts = (ArrayList<Object>) (((LinkedHashMap)p).get("amounts"));
amounts.forEach(amount -> {
System.out.println(((HashMap<String,Object>)amount).get("value"));
});
}
});
}
output is :
950.0

you will need the java-son library, if you need to extract the value of value this is how you can do it.
String ob = "{\n"
+ " \"arrival\": \"RONGO\",\n"
+ " \"segmentPrices\": [\n"
+ " {\n"
+ " \"id\": \"\",\n"
+ " \"localId\": \"\",\n"
+ " \"localCode\": \"\",\n"
+ " \"localDesignation\": \"\",\n"
+ " \"amounts\": [\n"
+ " {\n"
+ " \"value\": 950,\n"
+ " \"currency\": \"Ksh\"\n"
+ " }\n"
+ " ]\n"
+ " }\n"
+ " ]\n"
+ " } ";
JSONObject json = new JSONObject(ob.toString());
System.out.println(json.getJSONArray("segmentPrices").getJSONObject(0).getJSONArray("amounts").getJSONObject(0).get("value"));

check if there are two or more equal values in Json

How I should process this Json, to extract the cat1 value once in a Spinner, and in the second Spinner based on the first spinner selection I display book1 and book2.
Json:
{
"library":
[
{
"Cat": "cat1",
"Book": "book1",
"authur": "authur1"
},
{
"Cat": "cat1",
"Book": "book2",
"authur": "authur2"
},
{
"Cat": "cat2",
"Book": "book3",
"authur": "authur3"
}
]
}

You can simply use a library like Gson or Jackson for creating domain objects (you need to define them before) out of the Json. Afterwards you can easily extract whatever values you like.
This is an example:
http://www.mkyong.com/java/how-to-convert-java-object-to-from-json-jackson/

Parse your JSON data and store it into ArrayList and populate it on Spinner using ArrayAdapter.
Here is a sample code for parsing your JSON data:
public void parseJson() {
String response = "{\n" +
" \"library\":\n" +
"[\n" +
"{\n" +
" \"Cat\": \"cat1\",\n" +
" \"Book\": \"book1\",\n" +
" \"authur\": \"authur1\"\n" +
" },\n" +
" {\n" +
" \"Cat\": \"cat1\",\n" +
" \"Book\": \"book2\",\n" +
" \"authur\": \"authur2\"\n" +
" },\n" +
" {\n" +
" \"Cat\": \"cat2\",\n" +
" \"Book\": \"book3\",\n" +
" \"authur\": \"authur3\"\n" +
" }\n" +
"]\n" +
"}";
try {
JSONObject mJsonObject = new JSONObject(response);
JSONArray libraryJsonArray = mJsonObject.getJSONArray("library");
ArrayList<String> cats = new ArrayList<>();
ArrayList<String> books = new ArrayList<>();
ArrayList<String> authors = new ArrayList<>();
// Get all jsonObject from jsonArray
for (int i = 0; i < libraryJsonArray.length(); i++)
{
JSONObject jsonObject = libraryJsonArray.getJSONObject(i);
// Cat
if (jsonObject.has("Cat") && !jsonObject.isNull("Cat")) {
cats.add(jsonObject.getString("Cat"));
}
// Book
if (jsonObject.has("Book") && !jsonObject.isNull("Book")) {
books.add(jsonObject.getString("Book"));
}
// Author
if (jsonObject.has("authur") && !jsonObject.isNull("authur")) {
authors.add(jsonObject.getString("authur"));
}
Log.d("SUCCESS", "JSON Object: " + "\nCat: " + cats.get(i)
+ "\nBook: " + books.get(i) + "\nAuthor: " + authors.get(i));
// Do something with ArrayList cats, books and authors
}
} catch (JSONException e) {
Log.e("FAILED", "Json parsing error: " + e.getMessage());
}
}
OUTPUT:
D/SUCCESS: JSON Object:
Cat: cat1
Book: book1
Author: authur1
D/SUCCESS: JSON Object:
Cat: cat1
Book: book2
Author: authur2
D/SUCCESS: JSON Object:
Cat: cat2
Book: book3
Author: authur3

Use JSON object in java Hashmap

I want to retrieve all the values based on a key value from JSON object.
here's my sample JSON:
[{
"zip":544,
"type":"UNIQUE",
"primary_city":"Holtsville",
"acceptable_cities":"",
"unacceptable_cities":"Irs Service Center",
"state":"NY",
"county":"Suffolk County",
"timezone":"America/New_York",
"area_codes":"631",
"latitude":40.81,
"longitude":-73.04,
"world_region":"NA",
"country":"US",
"decommissioned":0,
"estimated_population":0,
"notes":""
},
{
"zip":601,
"type":"STANDARD",
"primary_city":"Adjuntas",
"acceptable_cities":"",
"unacceptable_cities":"Colinas Del Gigante, Jard De Adjuntas, Urb San Joaquin",
"state":"PR",
"county":"Adjuntas",
"timezone":"America/Puerto_Rico",
"area_codes":"787,939",
"latitude":18.16,
"longitude":-66.72,
"world_region":"NA",
"country":"US",
"decommissioned":0,
"estimated_population":0,
"notes":""
}]
So based on my zip code as key, I want to retrieve all other values.
I had tried the same thing for a JSON object with single key-value pairs, but don't know how to do it for above JSON object.
Here's my successfully running code for single key-value pairs
import java.util.HashMap;
import java.util.Iterator;
import org.json.JSONObject;
public class map {
public static void main(String[] args) {
String t = "{\"A\":\"A1\",\"B\":\"B1\",\"C\":\"C1\"}";
HashMap<String, String> map = new HashMap<String, String>();
JSONObject jObject = new JSONObject(t);
Iterator<?> keys = jObject.keys();
while( keys.hasNext() ){
String key = (String)keys.next();
String value = jObject.getString(key);
map.put(key, value);
}
System.out.println("json : "+jObject);
System.out.println("map : "+map.get("A"));
}
}
Output:
json : {"A":"A1","B":"B1","C":"C1"}
map : A1
any suggestions of how to do it?
I had seen several previous answers but none of them addresses this issue?

you can do it something like this. at the end of the loop your map will have zip to JSONObject mapping.
import org.json.JSONArray;
import org.json.JSONObject;
import java.util.HashMap;
import java.util.Map;
public class Main {
public static void main(String[] args) {
String json = "[{\n" +
" \"zip\":544,\n" +
" \"type\":\"UNIQUE\",\n" +
" \"primary_city\":\"Holtsville\",\n" +
" \"acceptable_cities\":\"\",\n" +
" \"unacceptable_cities\":\"Irs Service Center\",\n" +
" \"state\":\"NY\",\n" +
" \"county\":\"Suffolk County\",\n" +
" \"timezone\":\"America/New_York\",\n" +
" \"area_codes\":\"631\",\n" +
" \"latitude\":40.81,\n" +
" \"longitude\":-73.04,\n" +
" \"world_region\":\"NA\",\n" +
" \"country\":\"US\",\n" +
" \"decommissioned\":0,\n" +
" \"estimated_population\":0,\n" +
" \"notes\":\"\"\n" +
" },\n" +
" {\n" +
" \"zip\":601,\n" +
" \"type\":\"STANDARD\",\n" +
" \"primary_city\":\"Adjuntas\",\n" +
" \"acceptable_cities\":\"\",\n" +
" \"unacceptable_cities\":\"Colinas Del Gigante, Jard De Adjuntas, Urb San Joaquin\",\n" +
" \"state\":\"PR\",\n" +
" \"county\":\"Adjuntas\",\n" +
" \"timezone\":\"America/Puerto_Rico\",\n" +
" \"area_codes\":\"787,939\",\n" +
" \"latitude\":18.16,\n" +
" \"longitude\":-66.72,\n" +
" \"world_region\":\"NA\",\n" +
" \"country\":\"US\",\n" +
" \"decommissioned\":0,\n" +
" \"estimated_population\":0,\n" +
" \"notes\":\"\"\n" +
" }]";
Map<Integer, JSONObject> map = new HashMap<>();
JSONArray array = new JSONArray(json);
for (int i = 0; i < array.length(); i++) {
JSONObject jsonObject = array.getJSONObject(i);
map.put(jsonObject.getInt("zip"), jsonObject);
}
}
}

Traverse JSON data in JAVA

I am new to JSON..Am using HTTPUrlConnections and getting some response in JAVA program.The response data will be like,
{
"data": [
{
"id": 1,
"userId": 1,
"name": "ABC",
"modified": "2014-12-04",
"created": "2014-12-04",
"items": [
{
"email": "abc#gmail.com",
"links": [
{
.
.
.
.
}
]
}
]
}
]
}
From this response am able to get the value of "name" field with the below java code.
JSONArray items = newObj.getJSONArray("data");
for (int it=0 ; it < items.length() ; it++){
JSONObject contactItem = items.getJSONObject(it);
String userName = contactItem.getString("name");
System.out.println("Name----------"+userName);
}
But my requirement is,I need to get the value of "email" ..How should I code for that..
Any advice..
Thanks in advance..
Chitra

You need to first get the items array and each entry of this array contains JSONObject, from which you can call getString("email") .E.g.
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class App
{
public static void main( String[] args ) throws JSONException {
JSONObject newObj = new JSONObject("{" +
"\"data\": [\n" +
" {\n" +
"\"id\": 1,\n" +
" \"userId\": 1,\n" +
" \"name\": \"ABC\",\n" +
" \"modified\": \"2014-12-04\",\n" +
" \"created\": \"2014-12-04\",\n" +
" \"items\": [\n" +
" {\n" +
" \"email\": \"abc#gmail.com\",\n" +
" \"links\": [\n" +
" {\n" +
" }\n" +
" ]\n" +
" }\n" +
" ]\n" +
" }\n" +
" ]\n" +
"\n" +
"}");
JSONArray items = newObj.getJSONArray("data");
for (int it = 0; it < items.length(); it++) {
JSONObject contactItem = items.getJSONObject(it);
String userName = contactItem.getString("name");
JSONArray item = contactItem.getJSONArray("items");
for (int i = 0; i < items.length(); i++) {
String email = item.getJSONObject(i).getString("email");
System.out.println(email);
}
System.out.println("Name----------" + userName);
}
}
}
Output
abc#gmail.com
Name----------ABC

Extending your logic only:
JSONArray items = newObj.getJSONArray("data");
for (int it=0 ; it < items.length() ; it++){
JSONObject contactItem = items.getJSONObject(it);
String userName = contactItem.getString("name");
System.out.println("Name----------"+userName);
JSONArray itemsArr = contactItem.getJSONArray("items");
for (int item=0 ; item < itemsArr.length() ; item++){
String email = item.getString("email");
System.out.println("Email----------"+email);
}
}
This should work, with few tweaks. I have not actually tested it, just writing freehand here.

You can also use Jackson library from FasterXML. You can convert the JSON String into Java object very easily and then you can traverse using iterations on Collections.

If you look the JSON String it contains items which can be considered as an Array within an Array, so in order to get the value of email all you need to do is to create another JSONArray like:
JSONArray itemsArray = contactItem.getJSONArray("items");
Then you can retrieve the value of email over this Array

Thank you so much for your time and response.
The below code did the magic:
JSONArray responseContactData = responseContact.getJSONArray("data");
for (int i=0; i < responseContactData.length(); i++) {
String emails = contactDataValues.getJSONArray("items").getJSONObject(0).getString("email");
}

Parsing JSON string in Java

I am trying to parse a JSON string in java to have the individual value printed separately. But while making the program run I get the following error-
Exception in thread "main" java.lang.RuntimeException: Stub!
at org.json.JSONObject.<init>(JSONObject.java:7)
at ShowActivity.main(ShowActivity.java:29)
My Class looks like-
import org.json.JSONException;
import org.json.JSONObject;
public class ShowActivity {
private final static String jString = "{"
+ " \"geodata\": ["
+ " {"
+ " \"id\": \"1\","
+ " \"name\": \"Julie Sherman\","
+ " \"gender\" : \"female\","
+ " \"latitude\" : \"37.33774833333334\","
+ " \"longitude\" : \"-121.88670166666667\""
+ " }"
+ " },"
+ " {"
+ " \"id\": \"2\","
+ " \"name\": \"Johnny Depp\","
+ " \"gender\" : \"male\","
+ " \"latitude\" : \"37.336453\","
+ " \"longitude\" : \"-121.884985\""
+ " }"
+ " }"
+ " ]"
+ "}";
private static JSONObject jObject = null;
public static void main(String[] args) throws JSONException {
jObject = new JSONObject(jString);
JSONObject geoObject = jObject.getJSONObject("geodata");
String geoId = geoObject.getString("id");
System.out.println(geoId);
String name = geoObject.getString("name");
System.out.println(name);
String gender=geoObject.getString("gender");
System.out.println(gender);
String lat=geoObject.getString("latitude");
System.out.println(lat);
String longit =geoObject.getString("longitude");
System.out.println(longit);
}
}
Let me know what is it I am missing, or the reason why I do get that error everytime I run the application. Any comments would be appreciated.

See my comment.
You need to include the full org.json library when running as android.jar only contains stubs to compile against.
In addition, you must remove the two instances of extra } in your JSON data following longitude.
private final static String JSON_DATA =
"{"
+ " \"geodata\": ["
+ " {"
+ " \"id\": \"1\","
+ " \"name\": \"Julie Sherman\","
+ " \"gender\" : \"female\","
+ " \"latitude\" : \"37.33774833333334\","
+ " \"longitude\" : \"-121.88670166666667\""
+ " },"
+ " {"
+ " \"id\": \"2\","
+ " \"name\": \"Johnny Depp\","
+ " \"gender\" : \"male\","
+ " \"latitude\" : \"37.336453\","
+ " \"longitude\" : \"-121.884985\""
+ " }"
+ " ]"
+ "}";
Apart from that, geodata is in fact not a JSONObject but a JSONArray.
Here is the fully working and tested corrected code:
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
public class ShowActivity {
private final static String JSON_DATA =
"{"
+ " \"geodata\": ["
+ " {"
+ " \"id\": \"1\","
+ " \"name\": \"Julie Sherman\","
+ " \"gender\" : \"female\","
+ " \"latitude\" : \"37.33774833333334\","
+ " \"longitude\" : \"-121.88670166666667\""
+ " },"
+ " {"
+ " \"id\": \"2\","
+ " \"name\": \"Johnny Depp\","
+ " \"gender\" : \"male\","
+ " \"latitude\" : \"37.336453\","
+ " \"longitude\" : \"-121.884985\""
+ " }"
+ " ]"
+ "}";
public static void main(final String[] argv) throws JSONException {
final JSONObject obj = new JSONObject(JSON_DATA);
final JSONArray geodata = obj.getJSONArray("geodata");
final int n = geodata.length();
for (int i = 0; i < n; ++i) {
final JSONObject person = geodata.getJSONObject(i);
System.out.println(person.getInt("id"));
System.out.println(person.getString("name"));
System.out.println(person.getString("gender"));
System.out.println(person.getDouble("latitude"));
System.out.println(person.getDouble("longitude"));
}
}
}
Here's the output:
C:\dev\scrap>java -cp json.jar;. ShowActivity
1
Julie Sherman
female
37.33774833333334
-121.88670166666667
2
Johnny Depp
male
37.336453
-121.884985

To convert your JSON string to hashmap you can make use of this :
HashMap<String, Object> hashMap = new HashMap<>(Utility.jsonToMap(response)) ;
Use this class :) (handles even lists , nested lists and json)
public class Utility {
public static Map<String, Object> jsonToMap(Object json) throws JSONException {
if(json instanceof JSONObject)
return _jsonToMap_((JSONObject)json) ;
else if (json instanceof String)
{
JSONObject jsonObject = new JSONObject((String)json) ;
return _jsonToMap_(jsonObject) ;
}
return null ;
}
private static Map<String, Object> _jsonToMap_(JSONObject json) throws JSONException {
Map<String, Object> retMap = new HashMap<String, Object>();
if(json != JSONObject.NULL) {
retMap = toMap(json);
}
return retMap;
}
private static Map<String, Object> toMap(JSONObject object) throws JSONException {
Map<String, Object> map = new HashMap<String, Object>();
Iterator<String> keysItr = object.keys();
while(keysItr.hasNext()) {
String key = keysItr.next();
Object value = object.get(key);
if(value instanceof JSONArray) {
value = toList((JSONArray) value);
}
else if(value instanceof JSONObject) {
value = toMap((JSONObject) value);
}
map.put(key, value);
}
return map;
}
public static List<Object> toList(JSONArray array) throws JSONException {
List<Object> list = new ArrayList<Object>();
for(int i = 0; i < array.length(); i++) {
Object value = array.get(i);
if(value instanceof JSONArray) {
value = toList((JSONArray) value);
}
else if(value instanceof JSONObject) {
value = toMap((JSONObject) value);
}
list.add(value);
}
return list;
}
}

credit to this blog
This answer may help someone whose requirements are different.
This is your Json string
{
"pageNumber":20,
"pageTitle":"example page title",
"pageInfo": {
"pageName": "Homepage",
"logo": "https://www.example.com/logo.jpg"
},
"posts": [
{
"post_id": "0123456789",
"actor_id": "1001",
"author_name": "Jane Doe",
"post_title": "How to parse JSON in Java",
"comments": [],
"time_of_post": "1234567890"
}
]
}
and this is how to read it
import org.json.JSONArray;
import org.json.JSONObject;
public class ParseJSON {
static String json = "...";
public static void main(String[] args) {
JSONObject obj = new JSONObject(json);
String pageTitle = obj.getString("pageTitle");
String pageNumber= obj.getInt("pageNumber");
String pageName = obj.getJSONObject("pageInfo").getString("pageName");
System.out.println(pageNumber);
System.out.println(pageTitle );
System.out.println(pageName);
JSONArray arr = obj.getJSONArray("posts");
for (int i = 0; i < arr.length(); i++) {
String post_id = arr.getJSONObject(i).getString("post_id");
System.out.println(post_id);
}
}
}

Looks like for both of your objects (inside the array), you have an extra closing brace after "Longitude".

Firstly there is an extra } after every array object.
Secondly "geodata" is a JSONArray. So instead of JSONObject geoObject = jObject.getJSONObject("geodata"); you have to get it as JSONArray geoObject = jObject.getJSONArray("geodata");
Once you have the JSONArray you can fetch each entry in the JSONArray using geoObject.get(<index>).
I am using org.codehaus.jettison.json.

Here is the example of one Object, For your case you have to use JSONArray.
public static final String JSON_STRING="{\"employee\":{\"name\":\"Sachin\",\"salary\":56000}}";
try{
JSONObject emp=(new JSONObject(JSON_STRING)).getJSONObject("employee");
String empname=emp.getString("name");
int empsalary=emp.getInt("salary");
String str="Employee Name:"+empname+"\n"+"Employee Salary:"+empsalary;
textView1.setText(str);
}catch (Exception e) {e.printStackTrace();}
//Do when JSON has problem.
}
I don't have time but tried to give an idea. If you still can't do it, then I will help.

you have an extra "}" in each object,
you may write the json string like this:
public class ShowActivity {
private final static String jString = "{"
+ " \"geodata\": ["
+ " {"
+ " \"id\": \"1\","
+ " \"name\": \"Julie Sherman\","
+ " \"gender\" : \"female\","
+ " \"latitude\" : \"37.33774833333334\","
+ " \"longitude\" : \"-121.88670166666667\""
+ " }"
+ " },"
+ " {"
+ " \"id\": \"2\","
+ " \"name\": \"Johnny Depp\","
+ " \"gender\" : \"male\","
+ " \"latitude\" : \"37.336453\","
+ " \"longitude\" : \"-121.884985\""
+ " }"
+ " }"
+ " ]"
+ "}";
}