I have a list of JsonObject which is from google JSON library and then I need to call a third party library which accepts a JsonNode object from the Jackson library.
I don't have much experience with JSON and have been reading about these and from this link knows that JsonNode is a abstract class, hence can't create it and looks like I have to use ObjectNode for storing/converting the JsonObject but looks like it would require some parse to do that.
Could somebody please help me convert the JsonObject to ObjectNode ?
Could somebody please help me convert the JsonObject to ObjectNode?
It could be achieved with the following code:
private JsonNode toJsonNode(JsonObject jsonObject) throws IOException {
return mapper.readTree(jsonObject.toString());
}
To convert back, you may use:
private JsonObject toJsonObject(JsonNode jsonNode) throws IOException {
String jsonString = mapper.writeValueAsString(jsonNode);
JsonParser jsonParser = new JsonParser();
return jsonParser.parse(jsonString).getAsJsonObject();
}
Depending on your needs, for a more generic solution, you may consider using JsonElement rather than JsonObject. The code is very similar to the code shown above:
private JsonNode toJsonNode(JsonElement jsonElement) throws IOException {
return mapper.readTree(jsonElement.toString());
}
private JsonElement toJsonElement(JsonNode jsonNode) throws IOException {
String jsonString = mapper.writeValueAsString(jsonNode);
JsonParser jsonParser = new JsonParser();
return jsonParser.parse(jsonString);
}
I am writing automation script to validate json responses of REST APIs and i am using faster xml to serialize and convert java object to json format.
I have a user case where I have to get the json response and add a new array element to an existing array and post it back.
The json response after GET looks like this :
{
"name":"test",
"id":"1234",
"nodes":[
{
"nodeId":"node1"
},
{
"nodeId":"node2"
}
]
}
To this json response, I need to add a third entry for nodes array
{ "nodeId": "node3" } and then post this.
Can someone please help me understand how to add a new array element to an existing array?
You can try:
//Your JSON response will be in this format
String response = "{ \"name\":\"test\", \"id\":\"1234\", \"nodes\":[ { \"nodeId\":\"node1\" }, { \"nodeId\":\"node2\" } ] }";
try {
JSONObject jsonResponse = new JSONObject(response);
JSONArray nodesArray = jsonResponse.getJSONArray("nodes");
JSONObject newEntry = new JSONObject();
newEntry.put("nodeId","node3");
nodesArray.put(newEntry);
jsonResponse.put("nodes",nodesArray);
} catch (JSONException e) {
e.printStackTrace();
}
Now you can post your jsonResponse.toString() as required.
I would rather go for cleaner approach, create Object with below structure -
public class Response{
private String name;
private int id;
private List<Node> nodes;
<Getter & Setter>
}
public class Node{
private String nodeId;
}
Serialize the json -
Response response = objectMapper.readValue(responseJson,
Response.class);
Add the new incoming node object to response -
response.getNodes().add(New Node("{new node Value}"));
Deserialize before post -
objectMapper.writeValueAsString(response);
I am using the below code to convert json to xml of multiple XML files with different JSON structures.
String toXmlRequest = fullRequest.toString();
JSONObject jsonObj = new JSONObject(toXmlRequest);
String XmlRequest = XML.toString(jsonObj);
System.out.println(XmlRequest);
Input
{
"EnrollmentRequest":
{
"data":
{
"commonDataContext":
{
"requestId": "ADA12131",
"clientId": "ABCDEF",
"timestamp":"2013-12-13T11:10:00.715-05:00"
},
"cardNumber" : "123456789012345" ,
"firstName" : "John" ,
"lastName" : "Smith" ,
"email" : "JohnSmith#g.com" ,
"enrollStatus" : "E" ,
"pathEnroll" : "NewAcct",
"cardSavedIndicator" : "Y"
}
}
}
Output
<EnrollmentRequest>
<data>
<firstName>John</firstName>
<lastName>Smith</lastName>
<commonDataContext>
<clientId>ABCDEF</clientId>
<requestId>ADA12131</requestId>
<timestamp>2013-12-13T11:10:00.715-05:00</timestamp>
</commonDataContext>
<pathEnroll>NewAcct</pathEnroll>
<enrollStatus>E</enrollStatus>
<cardSavedIndicator>Y</cardSavedIndicator>
<cardNumber>123456789012345</cardNumber>
<email>JohnSmith#g.com</email>
</data>
</EnrollmentRequest>
The sequence of the output is getting changed. It is not able to keep the actual sequence. Is there any way this can be kept intact.
This is not possible using org.json.JSONObject directly. The reason is that JSONObject uses an internal store of type HashMap. HashMap does not preserve insertion order
It would be possible with a LinkedHashMap, however it does not appear possible to configure JSONObject to use one.
/**
* Construct an empty JSONObject.
*/
public JSONObject() {
this.map = new HashMap<String, Object>();
}
An alternative would be to read using a library that does preserve order, e.g. Jackson....
ObjectMapper mapper = new ObjectMapper();
JsonNode jackson = mapper.readTree(fullRequest);
and then feed that into XML
String xmlRequest = XML.toString(new JSONAdapter(jackson));
with the necessary type adaption to make the Jackson object look like a org.json.JSONObject. Incomplete example below:
private static class JSONAdapter extends JSONObject {
private JsonNode jackson;
public JSONAdapter(JsonNode jackson) {
this.jackson = jackson;
}
#Override
public Iterator<String> keys() {
return jackson.fieldNames();
}
#Override
public Object opt(String key) {
return get(key);
}
#Override
public Object get(String key) throws JSONException {
JsonNode nested = jackson.get(key);
if (nested.isObject()) {
return new JSONAdapter(nested);
} else if (nested.isTextual()) {
return nested.asText();
} else if (nested.isNumber()) {
return nested.asDouble();
} else if (nested.isBoolean()) {
return nested.asBoolean();
}
return null;
}
}
Output
<EnrollmentRequest>
<data>
<commonDataContext>
<requestId>ADA12131</requestId>
<clientId>ABCDEF</clientId>
<timestamp>2013-12-13T11:10:00.715-05:00</timestamp>
</commonDataContext>
<cardNumber>123456789012345</cardNumber>
<firstName>John</firstName>
<lastName>Smith</lastName>
<email>JohnSmith#g.com</email>
<enrollStatus>E</enrollStatus>
<pathEnroll>NewAcct</pathEnroll>
<cardSavedIndicator>Y</cardSavedIndicator>
</data>
</EnrollmentRequest>
For embedded json arrays, you need to apply one more condition to check if it array and return it as json array.
if(nested.isArray()) {
JSONArray arr = new JSONArray();
for(JsonNode value : nested){
arr.put(value.asText());
}
return arr;
}
I am trying to use org.json.JSONObject to build the following target json string:
{"und":[{"value":"some#one.com"}]}
Here is my code:
JSONObject und = new JSONObject();
und.accumulate("und", new JSONObject().put("value", "some#one.com"));
System.out.println( und.toString() );
But it produces the following:
{"und":{"value":"some#one.com"}}
How can I produce the target json string?
Thanks and regards.
EDIT
Thanks to SLaks's input, here is the code that produces the target string:
JSONObject und = new JSONObject();
JSONArray arr = new JSONArray();
und.put("und", arr);
arr.put(new JSONObject().put("value", "some#one.com"));
System.out.println( und.toString() );
You might want to take a look at Jackson, it's one of the most efficient and supported JSON libraries available on Java.
If you are familiar with unmarshalling/deserialization, you can turn an POJO into json and vise versa.
#JsonSerialize(include = JsonSerialize.Inclusion.NON_DEFAULT)
public class SomeBean {
Und[] und;
// TODO: Getters and setters
public static Und class {
public String value;
// TODO: Getters and setters
}
}
If you are directly parsing a JSON string or file, you can use the ObjectMapper class
SomeBean someBean = new ObjectMapper().readValue("input goes here", SomeBean.class);
// If you want just a string you can pass in the String class
String json = new ObjectMapper().readValue("input", String.class);
If the JSON is coming from a web service, check out Spring's restTemplate, super easy to work with.
RestTemplate restTemplate = new RestTemplate();
SomeBean someBean = restTemplate.getForEntity("URI goes here", SomeBean.class);
String json = restTemplate.getForEntity("URI goes here", String.class);
I have String variable called jsonString:
{"phonetype":"N95","cat":"WP"}
Now I want to convert it into JSON Object. I searched more on Google but didn't get any expected answers!
Using org.json library:
try {
JSONObject jsonObject = new JSONObject("{\"phonetype\":\"N95\",\"cat\":\"WP\"}");
}catch (JSONException err){
Log.d("Error", err.toString());
}
To anyone still looking for an answer:
JSONParser parser = new JSONParser();
JSONObject json = (JSONObject) parser.parse(stringToParse);
You can use google-gson. Details:
Object Examples
class BagOfPrimitives {
private int value1 = 1;
private String value2 = "abc";
private transient int value3 = 3;
BagOfPrimitives() {
// no-args constructor
}
}
(Serialization)
BagOfPrimitives obj = new BagOfPrimitives();
Gson gson = new Gson();
String json = gson.toJson(obj);
==> json is {"value1":1,"value2":"abc"}
Note that you can not serialize objects with circular references since that will result in infinite recursion.
(Deserialization)
BagOfPrimitives obj2 = gson.fromJson(json, BagOfPrimitives.class);
==> obj2 is just like obj
Another example for Gson:
Gson is easy to learn and implement, you need to know is the following two methods:
-> toJson() – convert java object to JSON format
-> fromJson() – convert JSON into java object
import com.google.gson.Gson;
public class TestObjectToJson {
private int data1 = 100;
private String data2 = "hello";
public static void main(String[] args) {
TestObjectToJson obj = new TestObjectToJson();
Gson gson = new Gson();
//convert java object to JSON format
String json = gson.toJson(obj);
System.out.println(json);
}
}
Output
{"data1":100,"data2":"hello"}
Resources:
Google Gson Project Home Page
Gson User Guide
Example
There are various Java JSON serializers and deserializers linked from the JSON home page.
As of this writing, there are these 22:
JSON-java.
JSONUtil.
jsonp.
Json-lib.
Stringtree.
SOJO.
json-taglib.
Flexjson.
Argo.
jsonij.
fastjson.
mjson.
jjson.
json-simple.
json-io.
google-gson.
FOSS Nova JSON.
Corn CONVERTER.
Apache johnzon.
Genson.
cookjson.
progbase.
...but of course the list can change.
Java 7 solution
import javax.json.*;
...
String TEXT;
JsonObject body = Json.createReader(new StringReader(TEXT)).readObject()
;
To convert String into JSONObject you just need to pass the String instance into Constructor of JSONObject.
Eg:
JSONObject jsonObj = new JSONObject("your string");
String to JSON using Jackson with com.fasterxml.jackson.databind:
Assuming your json-string represents as this: jsonString = {"phonetype":"N95","cat":"WP"}
import com.fasterxml.jackson.databind.JsonNode;
import com.fasterxml.jackson.databind.ObjectMapper;
/**
* Simple code exmpl
*/
ObjectMapper mapper = new ObjectMapper();
JsonNode node = mapper.readTree(jsonString);
String phoneType = node.get("phonetype").asText();
String cat = node.get("cat").asText();
I like to use google-gson for this, and it's precisely because I don't need to work with JSONObject directly.
In that case I'd have a class that will correspond to the properties of your JSON Object
class Phone {
public String phonetype;
public String cat;
}
...
String jsonString = "{\"phonetype\":\"N95\",\"cat\":\"WP\"}";
Gson gson = new Gson();
Phone fooFromJson = gson.fromJson(jsonString, Phone.class);
...
However, I think your question is more like, How do I endup with an actual JSONObject object from a JSON String.
I was looking at the google-json api and couldn't find anything as straight forward as
org.json's api which is probably what you want to be using if you're so strongly in need of using a barebones JSONObject.
http://www.json.org/javadoc/org/json/JSONObject.html
With org.json.JSONObject (another completely different API) If you want to do something like...
JSONObject jsonObject = new JSONObject("{\"phonetype\":\"N95\",\"cat\":\"WP\"}");
System.out.println(jsonObject.getString("phonetype"));
I think the beauty of google-gson is that you don't need to deal with JSONObject. You just grab json, pass the class to want to deserialize into, and your class attributes will be matched to the JSON, but then again, everyone has their own requirements, maybe you can't afford the luxury to have pre-mapped classes on the deserializing side because things might be too dynamic on the JSON Generating side. In that case just use json.org.
Those who didn't find solution from posted answers because of deprecation issues, you can use JsonParser from com.google.gson.
Example:
JsonObject jsonObject = JsonParser.parseString(jsonString).getAsJsonObject();
System.out.println(jsonObject.get("phonetype"));
System.out.println(jsonObject.get("cat"));
you must import org.json
JSONObject jsonObj = null;
try {
jsonObj = new JSONObject("{\"phonetype\":\"N95\",\"cat\":\"WP\"}");
} catch (JSONException e) {
e.printStackTrace();
}
Codehaus Jackson - I have been this awesome API since 2012 for my RESTful webservice and JUnit tests. With their API, you can:
(1) Convert JSON String to Java bean
public static String beanToJSONString(Object myJavaBean) throws Exception {
ObjectMapper jacksonObjMapper = new ObjectMapper();
return jacksonObjMapper.writeValueAsString(myJavaBean);
}
(2) Convert JSON String to JSON object (JsonNode)
public static JsonNode stringToJSONObject(String jsonString) throws Exception {
ObjectMapper jacksonObjMapper = new ObjectMapper();
return jacksonObjMapper.readTree(jsonString);
}
//Example:
String jsonString = "{\"phonetype\":\"N95\",\"cat\":\"WP\"}";
JsonNode jsonNode = stringToJSONObject(jsonString);
Assert.assertEquals("Phonetype value not legit!", "N95", jsonNode.get("phonetype").getTextValue());
Assert.assertEquals("Cat value is tragic!", "WP", jsonNode.get("cat").getTextValue());
(3) Convert Java bean to JSON String
public static Object JSONStringToBean(Class myBeanClass, String JSONString) throws Exception {
ObjectMapper jacksonObjMapper = new ObjectMapper();
return jacksonObjMapper.readValue(JSONString, beanClass);
}
REFS:
Codehaus Jackson
JsonNode API - How to use, navigate, parse and evaluate values from a JsonNode object
Tutorial - Simple tutorial how to use Jackson to convert JSON string to JsonNode
Converting String to Json Object by using org.json.simple.JSONObject
private static JSONObject createJSONObject(String jsonString){
JSONObject jsonObject=new JSONObject();
JSONParser jsonParser=new JSONParser();
if ((jsonString != null) && !(jsonString.isEmpty())) {
try {
jsonObject=(JSONObject) jsonParser.parse(jsonString);
} catch (org.json.simple.parser.ParseException e) {
e.printStackTrace();
}
}
return jsonObject;
}
To convert a string to json and the sting is like json. {"phonetype":"N95","cat":"WP"}
String Data=response.getEntity().getText().toString(); // reading the string value
JSONObject json = (JSONObject) new JSONParser().parse(Data);
String x=(String) json.get("phonetype");
System.out.println("Check Data"+x);
String y=(String) json.get("cat");
System.out.println("Check Data"+y);
Use JsonNode of fasterxml for the Generic Json Parsing. It internally creates a Map of key value for all the inputs.
Example:
private void test(#RequestBody JsonNode node)
input String :
{"a":"b","c":"d"}
If you are using http://json-lib.sourceforge.net
(net.sf.json.JSONObject)
it is pretty easy:
String myJsonString;
JSONObject json = JSONObject.fromObject(myJsonString);
or
JSONObject json = JSONSerializer.toJSON(myJsonString);
get the values then with
json.getString(param) or/and json.getInt(param) and so on.
No need to use any external library.
You can use this class instead :) (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;
}
}
To convert your JSON string to hashmap use this :
HashMap<String, Object> hashMap = new HashMap<>(Utility.jsonToMap(
For setting json single object to list
ie
"locations":{
}
in to List<Location>
use
ObjectMapper mapper = new ObjectMapper();
mapper.configure(DeserializationConfig.Feature.ACCEPT_SINGLE_VALUE_AS_ARRAY, true);
jackson.mapper-asl-1.9.7.jar
NOTE that GSON with deserializing an interface will result in exception like below.
"java.lang.RuntimeException: Unable to invoke no-args constructor for interface XXX. Register an InstanceCreator with Gson for this type may fix this problem."
While deserialize; GSON don't know which object has to be intantiated for that interface.
This is resolved somehow here.
However FlexJSON has this solution inherently. while serialize time it is adding class name as part of json like below.
{
"HTTPStatus": "OK",
"class": "com.XXX.YYY.HTTPViewResponse",
"code": null,
"outputContext": {
"class": "com.XXX.YYY.ZZZ.OutputSuccessContext",
"eligible": true
}
}
So JSON will be cumber some; but you don't need write InstanceCreator which is required in GSON.
Using org.json
If you have a String containing JSON format text, then you can get JSON Object by following steps:
String jsonString = "{\"phonetype\":\"N95\",\"cat\":\"WP\"}";
JSONObject jsonObj = null;
try {
jsonObj = new JSONObject(jsonString);
} catch (JSONException e) {
e.printStackTrace();
}
Now to access the phonetype
Sysout.out.println(jsonObject.getString("phonetype"));
Better Go with more simpler way by using org.json lib. Just do a very simple approach as below:
JSONObject obj = new JSONObject();
obj.put("phonetype", "N95");
obj.put("cat", "WP");
Now obj is your converted JSONObject form of your respective String. This is in case if you have name-value pairs.
For a string you can directly pass to the constructor of JSONObject. If it'll be a valid json String, then okay otherwise it'll throw an exception.