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How to get all key and values from nested JSON in java

Hi I need to read all key, values from nested JSON, where ever there is inner JSON. I need that values ignoring the key.From below JSON i need Key values for nested JSON, like: responseStatus-passed, "statusCode":"200", "retrieveQuoteResponse":null,"quoteGuid":null, etc.ignoring the start key value like: responsePreamble, quoteProductList which has a nested json inside it.
{
"responsePreamble": {
"responseStatus": "Passed",
"statusCode": "200",
"responseMessage": "Records Found"
},
"retrieveQuoteResponse": null,
"totalQuoteProductCount": 2,
"quoteProductList": {
"quoteGuid": null,
"quantity": 180
}
Code:
ObjectReader reader = new ObjectMapper().readerFor(Map.class);
Map<String, Map<String, String>> employeeMap = reader.readValue(jsonObject);
for (Entry<String, Map<String, String>> empMap : employeeMap.entrySet()) {
Map<String, String> addMap = empMap.getValue();
if(addMap!=null) {
for (Entry<String, String> addressSet : addMap.entrySet()) {
System.out.println(addressSet.getKey() + " :: " + addressSet.getValue());
}
}
}
OutPut:
responseStatus :: Passed
statusCode :: 200
responseMessage :: Records Found
Exception in thread "main" java.lang.ClassCastException: java.lang.String cannot be cast to java.util.Map
at com.im.api.tests.CompareTwoJsons.main(CompareTwoJsons.java:78)

For your specific case, the following code will do the job:
String json = "{\n" +
" \"responsePreamble\":{\n" +
" \"responseStatus\":\"Passed\",\n" +
" \"statusCode\":\"200\",\n" +
" \"responseMessage\":\"Records Found\",\n" +
" \"accountInfo\":{\n" +
" \"id\":\"631b3d5b-62c8-e711-80f3-3863bb343ba0\"\n" +
" },\n" +
" \"account\":\"40114570\",\n" +
" \"contactInfo\":{\n" +
" \"id\":\"1af63ebb-2680-eb11-a812-000d3a4e381d\"\n" +
" },\n" +
" \"contact\":\"Kenny Tokuda\",\n" +
" \"currencyInfo\":{\n" +
" \"id\":\"8c2ef-\",\n" +
" \"symbol\":\"$\"\n" +
" },\n" +
" \"vendorCurrencyInfo\":{\n" +
" \"id\":null\n" +
" }\n" +
" },\n" +
" \"retrieveQuoteResponse\":null,\n" +
" \"totalQuoteProductCount\":2,\n" +
" \"quoteProductList\":{\n" +
" \"quoteGuid\":null,\n" +
" \"quantity\":180\n" +
" }\n" +
"}";
ObjectMapper mapper = new ObjectMapper();
JsonNode jsonNode = mapper.readTree(json);
Iterator<String> iterator = jsonNode.fieldNames();
while (iterator.hasNext()) {
String key = iterator.next();
printRec(jsonNode, key);
}
Here is how function printRec looks like:
public static void printRec(JsonNode jsonNode, String key) {
JsonNode node = jsonNode.get(key);
if (node.isObject()) {
Iterator<Map.Entry<String, JsonNode>> fields = node.fields();
fields.forEachRemaining(field -> {
printRec(node, field.getKey());
if (!field.getValue().isObject()) {
System.out.println(field.getKey() + " : " + field.getValue());
}
});
}
}
When you run this code you should see the following output:
responseStatus : "Passed"
statusCode : "200"
responseMessage : "Records Found"
id : "631b3d5b-62c8-e711-80f3-3863bb343ba0"
account : "40114570"
id : "1af63ebb-2680-eb11-a812-000d3a4e381d"
contact : "Kenny Tokuda"
id : "8c2ef-"
symbol : "$"
id : null
quoteGuid : null
quantity : 180

Java: Create CSV from Get Array with Object

I have
data= [{
id=1,
employee_name=Tiger Nixon,
employee_salary=320800,
employee_age=61,
profile_image=
},
{
id=2,
employee_name=Garrett Winters,
employee_salary=170750,
employee_age=63,
profile_image=
},
{
id=3,
employee_name=Ashton Cox,
employee_salary=86000,
employee_age=66,
profile_image=
},
{
id=4,
employee_name=Cedric Kelly,
employee_salary=433060,
employee_age=22,
profile_image=
}
]
I have employee class
public class Employee {
private String employee_name;
private String employee_salary;
private String employee_age;
private String id;
private String profile_image;
public String toCsvRow() {
String csvRow = "";
for (String value : Arrays.asList(employee_name,employee_salary,employee_age)) {
String processed = value;
if (value.contains("\"") || value.contains(",")) {
processed = "\"" + value.replaceAll("\"", "\"\"") + "\"";
}
csvRow += "," + processed;
}
return csvRow.substring(1);
}
public String getEmployee_name() {
return employee_name;
}
public String getEmployee_salary() {
return employee_salary;
}
public String getEmployee_age() {
return employee_age;
}
}
I tried for
Map<String, ArrayList<Employee>> map = mapper.readValue(url, Map.class);
ArrayList<Employee> emps = map.get("data");
emps.get(0).toCsvRow()
Exception in thread "main" java.lang.ClassCastException: java.util.LinkedHashMap cannot be cast to org.example.model.Employee
Now I cannot call toCSVRow using emps.

Use Gson to parse JSON to ArrayList, for CSV conversion you can use org.json.CDL
See this is working fine
String str = "[{" +
" id=1," +
" employee_name=\"Tiger Nixon\"," +
" employee_salary=320800," +
" employee_age=61," +
" profile_image=\"khkjh\"" +
" }," +
" {" +
" id=2," +
" employee_name=\"Garrett Winters\"," +
" employee_salary=170750," +
" employee_age=63," +
" profile_image=\"\"" +
" }," +
" {" +
" id=3," +
" employee_name=\"Ashton Cox\"," +
" employee_salary=86000," +
" employee_age=66," +
" profile_image=\"\"" +
" }," +
" {" +
" id=4," +
" employee_name=\"Cedric Kelly\"," +
" employee_salary=433060," +
" employee_age=22," +
" profile_image=\"\"" +
" }" +
" ]";
try{
Gson gson = new Gson();
ArrayList<Employee> list = gson.fromJson(str, ArrayList.class);
String csv = CDL.toString(new JSONArray(list));
}catch (Exception e){
e.printStackTrace();
}
Output:
id,employee_name,employee_salary,employee_age,profile_image
1.0,Tiger Nixon,320800.0,61.0,khkjh
2.0,Garrett Winters,170750.0,63.0,
3.0,Ashton Cox,86000.0,66.0,
4.0,Cedric Kelly,433060.0,22.0

How wrap json array to custom object with collection via Gson?

How wrap json array to custom object with collection containing this array via Gson? I have following json string:
[
{
"showId":410,
"siteId":85,
"name":"Майстер і маргарита",
"duration":7200,
"providerId":1016,
"events":[
{
"siteId":85,
"eventSiteId":0,
"providerId":1016,
"eventId":1178,
"hallId":0,
"premiere":false,
"origin":"20140912190000"
}
]
}
]
and want to deserialize it to the object bellow:
public class Shows {
private List<Show> shows;
public List<Show> getShows() {
return shows;
}
public void setShows(List<Show> shows) {
this.shows = shows;
}
}

This Json message is represent a List<Show> that Show contains a List of Events as well.
This is not a Json of Shows, if so it should be like this.
{
"shows":[
{
"showId":410,
"siteId":85,
"name":"Майстер і маргарита",
"duration":7200,
"providerId":1016,
"events":[
{
"siteId":85,
"eventSiteId":0,
"providerId":1016,
"eventId":1178,
"hallId":0,
"premiere":false,
"origin":"20140912190000"
}
]
}
]
}
But you can try this way to get List<Show> and set it to Shows
You can try this way.
Type collectionType = new TypeToken<List<Show>>() {
}.getType();
String jsonString="[\n" +
"\n" +
" {\n" +
" \"showId\":410,\n" +
" \"siteId\":85,\n" +
" \"name\":\"Майстер і маргарита\",\n" +
" \"duration\":7200,\n" +
" \"providerId\":1016,\n" +
" \"events\":[\n" +
" {\n" +
" \"siteId\":85,\n" +
" \"eventSiteId\":0,\n" +
" \"providerId\":1016,\n" +
" \"eventId\":1178,\n" +
" \"hallId\":0,\n" +
" \"premiere\":false,\n" +
" \"origin\":\"20140912190000\"\n" +
" }\n" +
" ]\n" +
" }\n" +
"\n" +
"]";
List<Show> showList=new Gson().fromJson(jsonString,collectionType);
Shows shows=new Shows();
shows.setShows(showList);
System.out.println(shows);
My result.
Shows{shows=[Show{showId=410, siteId=85, name='Майстер і маргарита',
duration=7200, providerId=1016, events=[Events{siteId=85,
eventSiteId=0, providerId=1016, eventId=1178, hallId=0,
premiere=false, origin='20140912190000'}]}]}
My Show class.
public class Show {
private int showId;
private int siteId;
private String name;
private int duration;
private int providerId;
private List<Events> events;
//getters and setters
#Override
public String toString() {
return "Show{" +
"showId=" + showId +
", siteId=" + siteId +
", name='" + name + '\'' +
", duration=" + duration +
", providerId=" + providerId +
", events=" + events +
'}';
}
}
My Events class
public class Events {
private int siteId;
private int eventSiteId;
private int providerId;
private int eventId;
private int hallId;
private boolean premiere;
private String origin;
// getters and setters
#Override
public String toString() {
return "Events{" +
"siteId=" + siteId +
", eventSiteId=" + eventSiteId +
", providerId=" + providerId +
", eventId=" + eventId +
", hallId=" + hallId +
", premiere=" + premiere +
", origin='" + origin + '\'' +
'}';
}
}

You can try this.
//lets assume the json string to be in the variable data
Shows shows = new Gson().fromJson(data, Shows.class);

parsing json in java with "-" character before attribute name

i am trying to parse following json file.
"ItemData" : [{
"-item" : "A",
"id" : "100",
"name" : "abc",
"description" : "abcd",
"category" : "xyz",
}
]
I am able to parse everything except first field. Its because of "-" character in the beginning. I tried using #SerializedName("-item") in my POJO file. But does not work.
Can anybody tell me how can i parse this field?

I am not sure how your code looks like but #SerializedName("-item") seems to be working fine for me
class Data {
private List<ItemData> ItemData = new ArrayList<ItemData>();
#Override
public String toString() {
return "Data [ItemData=" + ItemData + "]";
}
}
class ItemData {
#SerializedName("-item")
private String _item;
private String id;
private String name;
private String description;
private String category;
#Override
public String toString() {
return "ItemData [_item=" + _item + ", id=" + id + ", name=" + name
+ ", description=" + description + ", category=" + category
+ "]";
}
}
Usage
Gson gson = new Gson();
String jsonString = "{\r\n" + " \"ItemData\" : [{\r\n"
+ " \"-item\" : \"A\",\r\n" + " \"id\" : \"100\",\r\n"
+ " \"name\" : \"abc\",\r\n"
+ " \"description\" : \"abcd\",\r\n"
+ " \"category\" : \"xyz\"\r\n" + " }\r\n" + " ]\r\n"
+ "}\r\n";
Data item = gson.fromJson(jsonString, Data.class);
System.out.println(item);
Output
Data [ItemData=[ItemData [_item=A, id=100, name=abc, description=abcd, category=xyz]]]
^^^^^^^

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\""
+ " }"
+ " }"
+ " ]"
+ "}";
}