How to access nested elements of json object using getJSONArray method
JavaJsonArraysJava Problem Overview
I have a JSON response that looks like this:
{
"result": {
"map": {
"entry": [
{
"key": { "@xsi.type": "xs:string", "$": "ContentA" },
"value": "fsdf"
},
{
"key": { "@xsi.type": "xs:string", "$": "ContentB" },
"value": "dfdf"
}
]
}
}
}
I want to access the value of the "entry" array object. I am trying to access:
RESPONSE_JSON_OBJECT.getJSONArray("entry");
I am getting JSONException. Can someone please help me get the JSON array from the above JSON response?
Java Solutions
Solution 1 - Java
You have to decompose the full object to reach the entry array.
Assuming REPONSE_JSON_OBJECT is already a parsed JSONObject.
REPONSE_JSON_OBJECT.getJSONObject("result")
.getJSONObject("map")
.getJSONArray("entry");
Solution 2 - Java
Try this code using Gson library and get the things done.
Gson gson = new GsonBuilder().create();
JsonObject job = gson.fromJson(JsonString, JsonObject.class);
JsonElement entry=job.getAsJsonObject("results").getAsJsonObject("map").getAsJsonArray("entry");
String str = entry.toString();
System.out.println(str);
Solution 3 - Java
I suggest you to use Gson library. It allows to parse JSON string into object data model. Please, see my example:
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.google.gson.annotations.SerializedName;
public class GsonProgram {
public static void main(String... args) {
String response = "{\"result\":{\"map\":{\"entry\":[{\"key\":{\"@xsi.type\":\"xs:string\",\"$\":\"ContentA\"},\"value\":\"fsdf\"},{\"key\":{\"@xsi.type\":\"xs:string\",\"$\":\"ContentB\"},\"value\":\"dfdf\"}]}}}";
Gson gson = new GsonBuilder().serializeNulls().create();
Response res = gson.fromJson(response, Response.class);
System.out.println("Entries: " + res.getResult().getMap().getEntry());
}
}
class Response {
private Result result;
public Result getResult() {
return result;
}
public void setResult(Result result) {
this.result = result;
}
@Override
public String toString() {
return result.toString();
}
}
class Result {
private MapNode map;
public MapNode getMap() {
return map;
}
public void setMap(MapNode map) {
this.map = map;
}
@Override
public String toString() {
return map.toString();
}
}
class MapNode {
List<Entry> entry = new ArrayList<Entry>();
public List<Entry> getEntry() {
return entry;
}
public void setEntry(List<Entry> entry) {
this.entry = entry;
}
@Override
public String toString() {
return Arrays.toString(entry.toArray());
}
}
class Entry {
private Key key;
private String value;
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public Key getKey() {
return key;
}
public void setKey(Key key) {
this.key = key;
}
@Override
public String toString() {
return "[key=" + key + ", value=" + value + "]";
}
}
class Key {
@SerializedName("$")
private String value;
@SerializedName("@xsi.type")
private String type;
public String getValue() {
return value;
}
public void setValue(String value) {
this.value = value;
}
public String getType() {
return type;
}
public void setType(String type) {
this.type = type;
}
@Override
public String toString() {
return "[value=" + value + ", type=" + type + "]";
}
}
Program output:
Entries: [[key=[value=ContentA, type=xs:string], value=fsdf], [key=[value=ContentB, type=xs:string], value=dfdf]]
If you not familiar with this library, then you can find a lot of informations in "Gson User Guide".
Solution 4 - Java
This is for Nikola.
public static JSONObject setProperty(JSONObject js1, String keys, String valueNew) throws JSONException {
String[] keyMain = keys.split("\\.");
for (String keym : keyMain) {
Iterator iterator = js1.keys();
String key = null;
while (iterator.hasNext()) {
key = (String) iterator.next();
if ((js1.optJSONArray(key) == null) && (js1.optJSONObject(key) == null)) {
if ((key.equals(keym)) && (js1.get(key).toString().equals(valueMain))) {
js1.put(key, valueNew);
return js1;
}
}
if (js1.optJSONObject(key) != null) {
if ((key.equals(keym))) {
js1 = js1.getJSONObject(key);
break;
}
}
if (js1.optJSONArray(key) != null) {
JSONArray jArray = js1.getJSONArray(key);
JSONObject j;
for (int i = 0; i < jArray.length(); i++) {
js1 = jArray.getJSONObject(i);
break;
}
}
}
}
return js1;
}
public static void main(String[] args) throws IOException, JSONException {
String text = "{ "key1":{ "key2":{ "key3":{ "key4":[ { "fieldValue":"Empty", "fieldName":"Enter Field Name 1" }, { "fieldValue":"Empty", "fieldName":"Enter Field Name 2" } ] } } } }";
JSONObject json = new JSONObject(text);
setProperty(json, "ke1.key2.key3.key4.fieldValue", "nikola");
System.out.println(json.toString(4));
}
If it's help bro,Do not forget to up for my reputation)))
Solution 5 - Java
You can try this:
JSONObject result = new JSONObject("Your string here").getJSONObject("result");
JSONObject map = result.getJSONObject("map");
JSONArray entries= map.getJSONArray("entry");
I hope this helps.
Solution 6 - Java
I'm also faced with this issue. So I solved with recursion. Maybe it will be helpfull. I created method.I used org.json library.
public static JSONObject function(JSONObject obj, String keyMain, String newValue) throws Exception {
// We need to know keys of Jsonobject
Iterator iterator = obj.keys();
String key = null;
while (iterator.hasNext()) {
key = (String) iterator.next();
// if object is just string we change value in key
if ((obj.optJSONArray(key)==null) && (obj.optJSONObject(key)==null)) {
if ((key.equals(keyMain)) && (obj.get(key).toString().equals(valueMain))) {
// put new value
obj.put(key, newValue);
return obj;
}
}
// if it's jsonobject
if (obj.optJSONObject(key) != null) {
function(obj.getJSONObject(key), keyMain, valueMain, newValue);
}
// if it's jsonarray
if (obj.optJSONArray(key) != null) {
JSONArray jArray = obj.getJSONArray(key);
for (int i=0;i<jArray.length();i++) {
function(jArray.getJSONObject(i), keyMain, valueMain, newValue);
}
}
}
return obj;
}
if you have questions, I can explain...
Solution 7 - Java
I would also try it this way
-
Create the Java Beans from the JSON schema
-
Use JSON parser libraries to avoid any sort of exception
-
Cast the parse result to the Java object that was created from the initial JSON schema.
Below is an example JSON Schema"
{
"USD" : {"15m" : 478.68, "last" : 478.68, "buy" : 478.55, "sell" : 478.68, "symbol" : "$"},
"JPY" : {"15m" : 51033.99, "last" : 51033.99, "buy" : 51020.13, "sell" : 51033.99, "symbol" : "¥"},
}
Code
public class Container {
private JPY JPY;
private USD USD;
public JPY getJPY ()
{
return JPY;
}
public void setJPY (JPY JPY)
{
this.JPY = JPY;
}
public USD getUSD ()
{
return USD;
}
public void setUSD (USD USD)
{
this.USD = USD;
}
@Override
public String toString()
{
return "ClassPojo [JPY = "+JPY+", USD = "+USD+"]";
}
}
public class JPY
{
@SerializedName("15m")
private double fifitenM;
private String symbol;
private double last;
private double sell;
private double buy;
public double getFifitenM ()
{
return fifitenM;
}
public void setFifitenM (double fifitenM)
{
this.fifitenM = fifitenM;
}
public String getSymbol ()
{
return symbol;
}
public void setSymbol (String symbol)
{
this.symbol = symbol;
}
public double getLast ()
{
return last;
}
public void setLast (double last)
{
this.last = last;
}
public double getSell ()
{
return sell;
}
public void setSell (double sell)
{
this.sell = sell;
}
public double getBuy ()
{
return buy;
}
public void setBuy (double buy)
{
this.buy = buy;
}
@Override
public String toString()
{
return "ClassPojo [15m = "+fifitenM+", symbol = "+symbol+", last = "+last+", sell = "+sell+", buy = "+buy+"]";
}
}
public class USD
{
@SerializedName("15m")
private double fifitenM;
private String symbol;
private double last;
private double sell;
private double buy;
public double getFifitenM ()
{
return fifitenM;
}
public void setFifitenM (double fifitenM)
{
this.fifitenM = fifitenM;
}
public String getSymbol ()
{
return symbol;
}
public void setSymbol (String symbol)
{
this.symbol = symbol;
}
public double getLast ()
{
return last;
}
public void setLast (double last)
{
this.last = last;
}
public double getSell ()
{
return sell;
}
public void setSell (double sell)
{
this.sell = sell;
}
public double getBuy ()
{
return buy;
}
public void setBuy (double buy)
{
this.buy = buy;
}
@Override
public String toString()
{
return "ClassPojo [15m = "+fifitenM+", symbol = "+symbol+", last = "+last+", sell = "+sell+", buy = "+buy+"]";
}
}
public class MainMethd
{
public static void main(String[] args) throws JsonIOException, JsonSyntaxException, FileNotFoundException {
// TODO Auto-generated method stub
JsonParser parser = new JsonParser();
Object obj = parser.parse(new FileReader("C:\\Users\\Documents\\file.json"));
String res = obj.toString();
Gson gson = new Gson();
Container container = new Container();
container = gson.fromJson(res, Container.class);
System.out.println(container.getUSD());
System.out.println("Sell Price : " + container.getUSD().getSymbol()+""+ container.getUSD().getSell());
System.out.println("Buy Price : " + container.getUSD().getSymbol()+""+ container.getUSD().getBuy());
}
}
Output from the main method is:
ClassPojo [15m = 478.68, symbol = $, last = 478.68, sell = 478.68, buy = 478.55]
Sell Price : $478.68
Buy Price : $478.55
Hope this helps.