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avoid adding the same element if exist in the list instead just add the elements inside the existing list [duplicate]

This question already has an answer here:
Add item to arraylist if it does not already exist in list
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Below is the sample code
String jsonString = "{\n" +
" \"models\":[\n" +
" {\n" +
" \"model\":{\n" +
" \"code\":\"ALL\",\n" +
" \"type\":null,\n" +
" \"name\":\"ALL\",\n" +
" \"feature_types\":null\n" +
" }\n" +
" },\n" +
" {\n" +
" \"model\":{\n" +
" \"code\":\"102e\",\n" +
" \"defaultLookup\":\"false\",\n" +
" \"type\":\"SIT\",\n" +
" \"name\":\"MUSTANG\",\n" +
" \"feature_types\":[\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"A\",\n" +
" \"desc\":\"All feature types\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"B\",\n" +
" \"desc\":\"Series\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"C\",\n" +
" \"desc\":\"BodyStyle\"\n" +
" }\n" +
" }\n" +
" ]\n" +
" }\n" +
" },\n" +
" {\n" +
" \"model\":{\n" +
" \"code\":\"980p\",\n" +
" \"defaultLookup\":\"false\",\n" +
" \"type\":\"SIT\",\n" +
" \"name\":\"Ranger\",\n" +
" \"feature_types\":[\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"C\",\n" +
" \"desc\":\"All feature types\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"D\",\n" +
" \"desc\":\"Series\"\n" +
" }\n" +
" } \n" +
" ]\n" +
" }\n" +
" },\n" +
" {\n" +
" \"model\":{\n" +
" \"code\":\"kkpou\",\n" +
" \"defaultLookup\":\"false\",\n" +
" \"type\":\"UAT\",\n" +
" \"name\":\"Transit Custom\",\n" +
" \"feature_types\":[\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"F\",\n" +
" \"desc\":\"All feature types\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"G\",\n" +
" \"desc\":\"Series\"\n" +
" }\n" +
" },\n" +
" {\n" +
" \"feature_type\":{\n" +
" \"code\":\"H\",\n" +
" \"desc\":\"Payload\"\n" +
" }\n" +
" }\n" +
" ]\n" +
" }\n" +
" }\n" +
" ]\n" +
"}";
for(int i = 0; i<myData.size();i++)
{
String type = "SIT";
FeaturedItems item = resultList.stream().filter(featureItem -> type != null && type.equals(featureItem.getType())).findFirst().orElse(null);
if (type != null) {
item = FeaturedItems.builder().type(type).items(new ArrayList<>()).build();
resultList.add(item);//if the item already exists in the list don't add the new item, instead just add the elements in the exisiting item.
//tried the below commented code to add the item if it doesn't contain in the list -- start
/*boolean flagFound = false;
for (FeaturedItems featureItem : resultList) {
if (featureItem.getType().equalsIgnoreCase(type)) {
flagFound = true;
break;
}
}
if(!flagFound) resultList.add(item);*/
//tried the above commented code to add the item if it doesn't contain in the list -- End
for (int count = 0; count < features.size(); count++) {
String id = getFid(count);
MyDataBuild build = ....//logic to set values in the properties
item.getItems().add(build);
}
}
}
lookUpData.setFeatureGroups(resultList);
}
}
If the type value is already defined in the defined featureItems, then instead of creating the new object in the featureItems list, i need to add the unique items(desc,id) to the existing items element for the matching type. The code snippet mentioned above doesn't add the elements to the existing items if the type is matching in the featureItems list, instead it is creating the new element as shown in the output json sample.

Using a Map instead will make your live much easier. However your example is missing some data so it's a bit hard to understand what is actually happening in your code. So I can give you only a simple example for the usage.
Map<String, FeaturedItems> resultMap = new HashMap<>();
// Get the FeaturedItems for the given type. If none is present create a new one.
FeaturedItems items = resultMap.computeIfAbsent(type, k -> FeaturedItems.builder().type(k).items(new ArrayList<>()).build());
// Add your item to the list
Sale newItem // Obtain new item
items.getItems().add(newItem);

How to using ObjectMapper to map value of an json property to Object when my object have an contractor set this property is null

I am usng google DirectionsResul Object
And then I want to using Object mapper to mapping this json to DirectionsResul Object
{
"geocoded_waypoints": [],
"routes": [
{
"bounds": {},
"legs": [
{
"distance": {
"human_readable": "13 km",
"in_meters": 13175
},
"duration": {
"human_readable": "37 phút",
"in_seconds": 2206
},
"steps": []
}
],
"overview_polyline": {
"points": "aaaa"
},
"warnings": [],
"waypoint_order": []
}
]
}
Using this code
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
DirectionsResult result;
result = objectMapper.readValue(json, DirectionsResult.class.);
All is ok but overview_polyline can't mapping, the points value is null
and I see in the EncodedPolyline have a contractor like this
public EncodedPolyline() {
this.points = null;
}
So how can I mapping the points value to the DirectionsResul Object
Here is my result I got
Here is all the code that can run
import com.fasterxml.jackson.databind.ObjectMapper;
import com.google.maps.model.DirectionsResult;
public void testGetDirections() throws NetworkException {
String json = "{\n" +
" \"geocoded_waypoints\": [],\n" +
" \"routes\": [\n" +
" {\n" +
" \"bounds\": {\n" +
" \"northeast\": {\n" +
" \"lat\": 34.1358593,\n" +
" \"lng\": -117.922066\n" +
" },\n" +
" \"southwest\": {\n" +
" \"lat\": 33.815582,\n" +
" \"lng\": -118.3516983\n" +
" }\n" +
" },\n" +
" \"legs\": [\n" +
" {\n" +
" \"distance\": {\n" +
" \"human_readable\": \"13 km\",\n" +
" \"in_meters\": 13175\n" +
" },\n" +
" \"duration\": {\n" +
" \"human_readable\": \"37 phút\",\n" +
" \"in_seconds\": 2206\n" +
" },\n" +
" \"steps\": [\n" +
" {\n" +
" \"distance\": {\n" +
" \"human_readable\": \"10 ft\",\n" +
" \"in_meters\": 3\n" +
" },\n" +
" \"duration\": {\n" +
" \"human_readable\": \"1 min\",\n" +
" \"in_seconds\": 0\n" +
" }\n" +
" }\n" +
" ]\n" +
" }\n" +
" ],\n" +
" \"overview_polyline\": {\n" +
" \"points\": \"{ashdasda}\"\n" +
" },\n" +
" \"warnings\": [],\n" +
" \"waypoint_order\": []\n" +
" }\n" +
" ]\n" +
"}";
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
DirectionsResult goongMapsDirectionResult;
try {
goongMapsDirectionResult = objectMapper.readValue(json, DirectionsResult.class.);
} catch (JsonProcessingException e) {
e.printStackTrace();
}
}

The problem is that there is no setter for points on EncodedPolyline.
One way to work around this is to use a DeserializationProblemHandler:
public class SO69242058 {
public static void main(String args[]) throws JsonProcessingException {
String json = "{\n" +
" \"geocoded_waypoints\": [],\n" +
" \"routes\": [\n" +
" {\n" +
" \"bounds\": {\n" +
" \"northeast\": {\n" +
" \"lat\": 34.1358593,\n" +
" \"lng\": -117.922066\n" +
" },\n" +
" \"southwest\": {\n" +
" \"lat\": 33.815582,\n" +
" \"lng\": -118.3516983\n" +
" }\n" +
" },\n" +
" \"legs\": [\n" +
" {\n" +
" \"distance\": {\n" +
" \"human_readable\": \"13 km\",\n" +
" \"in_meters\": 13175\n" +
" },\n" +
" \"duration\": {\n" +
" \"human_readable\": \"37 phút\",\n" +
" \"in_seconds\": 2206\n" +
" },\n" +
" \"steps\": [\n" +
" {\n" +
" \"distance\": {\n" +
" \"human_readable\": \"10 ft\",\n" +
" \"in_meters\": 3\n" +
" },\n" +
" \"duration\": {\n" +
" \"human_readable\": \"1 min\",\n" +
" \"in_seconds\": 0\n" +
" }\n" +
" }\n" +
" ]\n" +
" }\n" +
" ],\n" +
" \"overview_polyline\": {\n" +
" \"points\": \"{ashdasda}\"\n" +
" },\n" +
" \"warnings\": [],\n" +
" \"waypoint_order\": []\n" +
" }\n" +
" ]\n" +
"}";
ObjectMapper objectMapper = new ObjectMapper();
objectMapper.setPropertyNamingStrategy(PropertyNamingStrategy.SNAKE_CASE);
//objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
objectMapper.addHandler(new DeserializationProblemHandler() {
#Override
public boolean handleUnknownProperty(DeserializationContext ctxt, JsonParser p,
JsonDeserializer<?> deserializer, Object beanOrClass,
String propertyName) throws IOException {
EncodedPolyline encodedPolyline = (EncodedPolyline)beanOrClass;
try {
Field f = EncodedPolyline.class.getDeclaredField("points");
f.setAccessible(true);
f.set(encodedPolyline, p.readValueAs(String.class));
} catch (NoSuchFieldException | IllegalAccessException e) {
throw new RuntimeException(e);
}
return true;
}
});
DirectionsResult goongMapsDirectionResult;
goongMapsDirectionResult = objectMapper.readValue(json, DirectionsResult.class);
}
}
I've removed objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES) so that the error occurs when Jackson tries to set points. Then we set it reflectively.

java - Splitting JSON string into JSON strings in Java

I have below json string
{
"folderId":1,
"parentIds":{},
"folderName":null,
"hiddenFlag":true,
"autoExecute":false,
"updatedDate":"2020-10-15T11:40:55.000Z",
"widgetItems":[
{
"width":4,
"property":{
"name":"GRID",
"widgetdef":{
"id":"91209e5a-6468-4912-b35a-ebfe84ac867e",
"name":"GRID",
"Title":{
"type":"TEXT",
"value":""
},
"dimCount":0,
"reportTO":{
"source":{
"sourceId":388
},
"columns":[
{
"id":null,
"function":"SUM",
"operationErrorCode":0,
"totalAllUsingFunction":"Auto"
},
{
"id":null,
"function":"SUM",
"operationErrorCode":0,
"totalAllUsingFunction":"Auto"
}
],
"columnSummaryType":0,
"drilldownDefaultDimension":{
}
},
"splitBar":{
"value":true
},
"isExistingDashboard":true,
"dimensionColumnCount":0
}
}
}
],
"dashboardName":"Second Dashboard",
"dashboardType":1,
"parentFolderId":1,
"dashboardId":90208
}
Am expecting output below json after split..I want to split reportTO object
{
"source": {
"sourceId": 388
},
"columns": [{
"id": null,
"function": "SUM",
"operationErrorCode": 0,
"totalAllUsingFunction": "Auto"
},
{
"id": null,
"function": "SUM",
"operationErrorCode": 0,
"totalAllUsingFunction": "Auto"
}
],
"columnSummaryType": 0,
"drilldownDefaultDimension": {}
}

public static void main(String[] args) throws IOException {
String rootJson = " {\r\n" +
" \"folderId\": 1,\r\n" +
" \"parentIds\": {},\r\n" +
" \"folderName\": null,\r\n" +
" \"hiddenFlag\": true,\r\n" +
" \"autoExecute\": false,\r\n" +
" \"updatedDate\": \"2020-10-15T11:40:55.000Z\",\r\n" +
" \"widgetItems\": [\r\n" +
" { \r\n" +
" \"width\": 4,\r\n" +
" \"property\": {\r\n" +
" \"name\": \"GRID\",\r\n" +
" \"widgetdef\": {\r\n" +
" \"id\": \"91209e5a-6468-4912-b35a-ebfe84ac867e\",\r\n" +
" \"name\": \"GRID\",\r\n" +
" \"Title\": {\r\n" +
" \"type\": \"TEXT\",\r\n" +
" \"value\": \"\"\r\n" +
" }, \r\n" +
" \"dimCount\": 0,\r\n" +
" \"reportTO\": {\r\n" +
" \"source\": {\r\n" +
" \"sourceId\": 388\r\n" +
" },\r\n" +
" \"columns\": [\r\n" +
" {\r\n" +
" \"id\": null, \r\n" +
" \"function\": \"SUM\", \r\n" +
" \"operationErrorCode\": 0,\r\n" +
" \"totalAllUsingFunction\": \"Auto\"\r\n" +
" },\r\n" +
" {\r\n" +
" \"id\": null, \r\n" +
" \"function\": \"SUM\", \r\n" +
" \"operationErrorCode\": 0,\r\n" +
" \"totalAllUsingFunction\": \"Auto\"\r\n" +
" } \r\n" +
" ], \r\n" +
" \"columnSummaryType\": 0,\r\n" +
" \"drilldownDefaultDimension\": {}\r\n" +
" },\r\n" +
" \"splitBar\": {\r\n" +
" \"value\": true\r\n" +
" }, \r\n" +
" \"isExistingDashboard\": true,\r\n" +
" \"dimensionColumnCount\": 0\r\n" +
" }\r\n" +
" }\r\n" +
" } \r\n" +
" ],\r\n" +
" \"dashboardName\": \"Second Dashboard\",\r\n" +
" \"dashboardType\": 1,\r\n" +
" \"parentFolderId\": 1, \r\n" +
" \"dashboardId\": 90208\r\n" +
"}";
JSONObject jsonObject = new JSONObject(rootJson);
JSONObject reportJson = jsonObject.getJSONArray("widgetItems").getJSONObject(0).
getJSONObject("property").
getJSONObject("widgetdef").
getJSONObject("reportTO");
System.out.println(reportJson);
}
OUTPUT
{
"drilldownDefaultDimension":{
},
"columns":[
{
"function":"SUM",
"totalAllUsingFunction":"Auto",
"id":null,
"operationErrorCode":0
},
{
"function":"SUM",
"totalAllUsingFunction":"Auto",
"id":null,
"operationErrorCode":0
}
],
"columnSummaryType":0,
"source":{
"sourceId":388
}
}

How can I parse JSON Array Using Retrofit and GSON?

I have learnend how to parsing JSON objects via Retrofit Gson but I need to parse a full JSON array via Retrofit Gson.
I need to parse the following :
"{\n" +
" \"snappedPoints\": [\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.2784167,\n" +
" \"longitude\": 149.1294692\n" +
" },\n" +
" \"originalIndex\": 0,\n" +
" \"placeId\": \"ChIJoR7CemhNFmsRQB9QbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.280321693840129,\n" +
" \"longitude\": 149.12908274880189\n" +
" },\n" +
" \"originalIndex\": 1,\n" +
" \"placeId\": \"ChIJiy6YT2hNFmsRkHZAbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.280960897210818,\n" +
" \"longitude\": 149.1293250692261\n" +
" },\n" +
" \"originalIndex\": 2,\n" +
" \"placeId\": \"ChIJW9R7smlNFmsRMH1AbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.28142839817933,\n" +
" \"longitude\": 149.1298619971291\n" +
" },\n" +
" \"originalIndex\": 3,\n" +
" \"placeId\": \"ChIJy8c0r2lNFmsRQEZUbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.28193988170618,\n" +
" \"longitude\": 149.13001013387623\n" +
" },\n" +
" \"originalIndex\": 4,\n" +
" \"placeId\": \"ChIJ58xCoGlNFmsRUEZUbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.282819705480151,\n" +
" \"longitude\": 149.1295597114644\n" +
" },\n" +
" \"originalIndex\": 5,\n" +
" \"placeId\": \"ChIJabjuhGlNFmsREIxAbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.283139388422363,\n" +
" \"longitude\": 149.12895618087012\n" +
" },\n" +
" \"originalIndex\": 6,\n" +
" \"placeId\": \"ChIJ1Wi6I2pNFmsRQL9GbW7qABM\"\n" +
" },\n" +
" {\n" +
" \"location\": {\n" +
" \"latitude\": -35.284728724835304,\n" +
" \"longitude\": 149.12835061713685\n" +
" },\n" +
" \"originalIndex\": 7,\n" +
" \"placeId\": \"ChIJW5JAZmpNFmsRegG0-Jc80sM\"\n" +
" }\n" +
" ]\n" +
"}"
I need the lat and longs only.
Here is the method I know to parse JSON Objects via Retrofit GSON
package com.example.akshay.retrofitgson;
import com.google.gson.annotations.Expose;
import com.google.gson.annotations.SerializedName;
/**
* Created by Akshay on 9/6/2015.
*/
public class gitmodel {
#SerializedName("latitude")
#Expose
public String latitude;
#SerializedName("longitude")
#Expose
public String longitude;
public void setLatitude(String latitude)
{
this.latitude = latitude;
}
public String getLatitude()
{
return latitude;
}
public void setLongitude(String longitude)
{
this.longitude = longitude;
}
public String getlatitude()
{
return latitude;
}
}

You might need the lat/longs only, but the easiest thing to do is to just set up your POJO to get everything, then extract the lat longs from the POJO. You can even design the deserialized object to hide the inner object if you want. In the case of your JSON, this is quite easy, just do this:
public static class SnappedPoints {
private List<Point> snappedPoints;
public String toString() {
return snappedPoints.toString();
}
}
public static class Point {
private Location location;
public double getLatitude() {
return location.getLatitude();
}
public double getLongitude() {
return location.getLongitude();
}
public String toString() {
return "{" + location.getLatitude() + "," + location.getLongitude() + "}";
}
}
public static class Location {
double latitude;
double longitude;
public double getLatitude() {
return latitude;
}
public double getLongitude() {
return longitude;
}
}
You can see this in action by simply doing this:
public static void main(String[] args) {
System.out.println(new Gson().fromJson(json, SnappedPoints.class));
}
Or, in the case of Retrofit, something like this:
public interface MyRetrofitAPI {
#GET("/path/to/json")
void getSnappedPoints(/* arguments */, Callback<SnappedPoints> callback);
}

Retrofit uses the Gson library to serialise Json responses. As long as you have a model class setup correctly, you can tell Gson to try and serialise the json into an instance of that model class. Your code should look something like the following:
String json; // retrieved from file/server
MyObject myObject = new Gson().fromJson(json, MyObject.class)

How to get a value from a JSON string using jackson library?

I am trying to get a value from a JSON string but I am getting a null value instead.
App2.java :
package JsonExample1;
import org.codehaus.jackson.JsonNode;
import org.codehaus.jackson.map.ObjectMapper;
import java.io.IOException;
import java.io.StringReader;
public class App2 {
private JsonNode rootNode;
public void setup() throws IOException {
String jsonString = "{\n" +
" \"HotelListResponse\" : {\n" +
" \"customerSessionId\" : \"0ABAAA7A-90C9-7491-3FF2-7E2C37496CA2\",\n" +
" \"numberOfRoomsRequested\" : 1,\n" +
" \"moreResultsAvailable\" : true,\n" +
" \"cacheKey\" : \"7790c974:13ff7e2c374:6ccd\",\n" +
" \"cacheLocation\" : \"10.186.170.122:7300\",\n" +
" \"HotelList\" : {\n" +
" \"#activePropertyCount\" : \"223\",\n" +
" \"#size\" : \"1\",\n" +
" \"HotelSummary\" : {\n" +
" \"#order\" : \"0\",\n" +
" \"hotelId\" : 125727,\n" +
" \"name\" : \"Red Lion Hotel on Fifth Avenue\",\n" +
" \"address1\" : \"1415 5th Ave\",\n" +
" \"city\" : \"Seattle\",\n" +
" \"stateProvinceCode\" : \"WA\",\n" +
" \"postalCode\" : 98101,\n" +
" \"countryCode\" : \"US\",\n" +
" \"airportCode\" : \"SEA\",\n" +
" \"supplierType\" : \"E\",\n" +
" \"hotelRating\" : 3.5,\n" +
" \"propertyCategory\" : 1,\n" +
" \"confidenceRating\" : 90,\n" +
" \"amenityMask\" : 7847938,\n" +
" \"tripAdvisorRating\" : 4,\n" +
" \"locationDescription\" : \"Near Pike Place Market\",\n" +
" \"shortDescription\" : \"<p><b>Location. </b> <br />Red Lion Hotel on Fifth Avenue is located close to 5th Avenue Theater, Pike Place Market, and Washington State Convention & Trade Center. Additional points of interest\",\n" +
" \"highRate\" : 149,\n" +
" \"lowRate\" : 126.65,\n" +
" \"rateCurrencyCode\" : \"USD\",\n" +
" \"latitude\" : 47.60985,\n" +
" \"longitude\" : -122.33475,\n" +
" \"proximityDistance\" : 11.168453,\n" +
" \"proximityUnit\" : \"MI\",\n" +
" \"hotelInDestination\" : true,\n" +
" \"thumbNailUrl\" : \"/hotels/1000000/60000/51000/50947/50947_180_t.jpg\",\n" +
" \"deepLink\" : \"http://travel.ian.com/index.jsp?pageName=hotAvail&cid=55505&hotelID=125727&mode=2&numberOfRooms=1&room-0-adult-total=2&room-0-child-total=0&arrivalMonth=8&arrivalDay=4&departureMonth=8&departureDay=5&showInfo=true&locale=en_US&currencyCode=USD\",\n" +
" \"RoomRateDetailsList\" : {\n" +
" \"RoomRateDetails\" : {\n" +
" \"roomTypeCode\" : 253461,\n" +
" \"rateCode\" : 201054304,\n" +
" \"maxRoomOccupancy\" : 2,\n" +
" \"quotedRoomOccupancy\" : 2,\n" +
" \"minGuestAge\" : 0,\n" +
" \"roomDescription\" : \"Classic Single Queen\",\n" +
" \"promoId\" : 202161947,\n" +
" \"promoDescription\" : \"Summer Sale! Save 15%\",\n" +
" \"currentAllotment\" : 0,\n" +
" \"propertyAvailable\" : true,\n" +
" \"propertyRestricted\" : false,\n" +
" \"expediaPropertyId\" : 50947,\n" +
" \"rateKey\" : \"0ABAAA7A-90C9-7491-3FF2-7E2C37496CCE\",\n" +
" \"RateInfo\" : {\n" +
" \"#rateChange\" : \"false\",\n" +
" \"#promo\" : \"true\",\n" +
" \"#priceBreakdown\" : \"true\",\n" +
" \"ChargeableRateInfo\" : {\n" +
" \"#total\" : \"151.23\",\n" +
" \"#surchargeTotal\" : \"24.58\",\n" +
" \"#nightlyRateTotal\" : \"126.65\",\n" +
" \"#maxNightlyRate\" : \"126.65\",\n" +
" \"#currencyCode\" : \"USD\",\n" +
" \"#commissionableUsdTotal\" : \"126.65\",\n" +
" \"#averageRate\" : \"126.65\",\n" +
" \"#averageBaseRate\" : \"149.0\",\n" +
" \"NightlyRatesPerRoom\" : {\n" +
" \"#size\" : \"1\",\n" +
" \"NightlyRate\" : {\n" +
" \"#promo\" : \"true\",\n" +
" \"#rate\" : \"126.65\",\n" +
" \"#baseRate\" : \"149.0\"\n" +
" }\n" +
" },\n" +
" \"Surcharges\" : {\n" +
" \"#size\" : \"1\",\n" +
" \"Surcharge\" : {\n" +
" \"#amount\" : \"24.58\",\n" +
" \"#type\" : \"TaxAndServiceFee\"\n" +
" }\n" +
" }\n" +
" }\n" +
" },\n" +
" \"ValueAdds\" : {\n" +
" \"#size\" : \"1\",\n" +
" \"ValueAdd\" : {\n" +
" \"#id\" : \"2048\",\n" +
" \"description\" : \"Free Wireless Internet\"\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }\n" +
" }";
rootNode = new ObjectMapper().readTree(new StringReader(jsonString));
}
//other methods
public void basicTreeModelRead()
{
//Just like DOM, our data is in a hierarchy of node (in this case, it is JsonNode)
JsonNode aField = rootNode.get("customerSessionId");
//the customerSessionId has a String value
String myString = aField.asText();
System.out.println("customerSessionId is:" + myString);
}
}
StartHere.java:
package JsonExample1;
import java.io.IOException;
public class StartHere {
public static void main(String[] args) {
App2 myApp = new App2();
try {
myApp.setup();
} catch (IOException e) {
e.printStackTrace(); //To change body of catch statement use File | Settings | File Templates.
}
myApp.basicTreeModelRead();
}
}
After debugging I found that aField value remains null.
Any ideas?

Your root node doesn't have a customerSessionId, it has a HotelListResponse. Get that first.
//other methods
public void basicTreeModelRead()
{
JsonNode innerNode = rootNode.get("HotelListResponse"); // Get the only element in the root node
// get an element in that node
JsonNode aField = innerNode.get("customerSessionId");
//the customerSessionId has a String value
String myString = aField.asText();
System.out.println("customerSessionId is:" + myString);
}
This prints
customerSessionId is:0ABAAA7A-90C9-7491-3FF2-7E2C37496CA2

Another way to get the inner element, with .at() method:
rootNode.at("/HotelListResponse/customerSessionId")

Convert to the Map
Map map = objectMapper.readValue(jsonString, Map.class);
Method for navigation in the map
private static <T> T get(Map map, Class<T> clazz, String... path) {
Map node = map;
for (int i = 0; i < path.length - 1; i++) {
node = (Map) node.get(path[i]);
}
return (T) node.get(path[path.length - 1]);
}
Usage:
String value = get(map, String.class, "path", "to", "the", "node")