I need to get the value of the key from a dynamic json.
Input-> json Object, String key
Output-> json element(corresponds to the value of the key)
Example
JsonObject Jmsg =
{
"id": "1753_CORE1",
"name": "Gtx cuda Service:1753",
"shortName": "gt-service-1753",
"createdDate": "Mar 31, 2015 4:47:10 PM",
"config": {
"oauthSecret": [
{
"id": 45,
"config123": {
"oauthSecret": "P8n2x5Hsst0nFRRB0A",
"status": "CREATED"
},
"SERVER132": "1000"
},
{
"id": 46,
"config123": {
"oauthSecret": "P8n2x5Htss0nFRRB0A"
},
"SERVER132": "1000"
}
],
"oauthKey": "154284-service-1753",
"SERVER": "1000"
},
"features": [
9004,
9005
]
}
and String key = "status";
then
JsonElement Jvalue = jsonGetValueformKey(Jmsg,key);
should return 'CREATED' in JsonElement or string type.
if String key = "features";
then
JsonElement Jvalue = jsonGetValueformKey(Jmsg,key);
should return [9004,9005] in JsonElement or jsonArray type.
if key not found then return null
JsonObject Jmsg can be anything
please try this
package json;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import com.google.gson.JsonElement;
import com.google.gson.JsonParser;
public class MyApp {
static List<String> list = new ArrayList<String>();
public static void main(String[] args) {
String key = "oauthSecret";
String json2 = "{\"config\": {\"oauthSecret\": [{\"id\": 45,\"config123\": {\"oauthSecret\": \"P8n2x5Ht0nFRRB0A\",\"status\": \"CREATED\"},\"SERVER132\": \"1000\"},{\"id\": 46,\"config123\": {\"oauthSecret\": \"wP8n2x5Ht0nFRRB0A\",\"status\": \"CREATED\"},\"SERVER132\": \"1000\"}],\"oauthKey\": \"newtest\",\"SERVER\": \"1000\"},\"features\": [ 9004, 9005] ,\"d\":\"dd\"}";
System.out.println("JSON: " + json2);
JsonParser p = new JsonParser();
check(key, p.parse(json2));
System.out.println("list size: " + list.size());
System.out.println(list);
}
private static void check(String key, JsonElement jsonElement) {
if (jsonElement.isJsonArray()) {
for (JsonElement jsonElement1 : jsonElement.getAsJsonArray()) {
check(key, jsonElement1);
}
} else {
if (jsonElement.isJsonObject()) {
Set<Map.Entry<String, JsonElement>> entrySet = jsonElement
.getAsJsonObject().entrySet();
for (Map.Entry<String, JsonElement> entry : entrySet) {
String key1 = entry.getKey();
if (key1.equals(key)) {
list.add(entry.getValue().toString());
}
check(key, entry.getValue());
}
} else {
if (jsonElement.toString().equals(key)) {
list.add(jsonElement.toString());
}
}
}
}
}
This is a draft of a recursive approach for that.
Object find(JSONObject jObj, String k) throws JSONException {
Iterator<?> keys = jObj.keys();
while( keys.hasNext() ) {
String key = (String)keys.next();
if (key.equals(k)) {
return jObj.get(key);
}
if ( jObj.get(key) instanceof JSONObject ) {
return find((JSONObject)jObj.get(key), k);
}
if ( jObj.get(key) instanceof JSONArray ) {
JSONArray jar = (JSONArray)jObj.get(key);
for (int i = 0; i < jar.length(); i++) {
JSONObject j = jar.getJSONObject(i);
find(j, k);
}
}
}
You could use something like this :-
public Object checkKey(JSONObject object, String searchedKey) {
boolean exists = object.containsKey(searchedKey);
Object obj = null;
if(exists){
obj = object.get(searchedKey);
}
if(!exists) {
Set<String> keys = object.keySet();
for(String key : keys){
if ( object.get(key) instanceof JSONObject ) {
obj = checkKey((JSONObject)object.get(key), searchedKey);
}
}
}
return obj;
}
This will give you the Object type for a key OR null if key does not exists.
You can modify it & caste the return Object type to any JSONObject, String or JSONArray depending upon your condition by checking its class using getClass().
Note :- This is just a reference but you can edit it according to your needs.
private Object findJsonParam(JSONObject payload, String param) {
Iterator<?> keys = payload.keys();
System.out.println("payload " + payload);
while (keys.hasNext()) {
String key = (String) keys.next();
if (key.equals(param)) {
return payload.get(key);
} else if (payload.get(key) instanceof JSONObject) {
Object val = findJsonParam(payload.getJSONObject(key), param);
if (val != null)
return val;
} else if (payload.get(key) instanceof JSONArray) {
JSONArray jar = payload.getJSONArray(key);
for (Object jsonObj : jar) {
Object val = findJsonParam((JSONObject) jsonObj, param);
if (val != null)
return val;
}
}
}
return null;
}
I had to make some changes in DrB awnser, it worked for me this way. Because on the first nested json it returned without checking the value, so if the key wasn't in the first one, then it couldn't find it.
public Object find(JSONObject jObj, String k) throws JSONException {
Iterator<?> keys = jObj.keys();
while (keys.hasNext()) {
String key = (String) keys.next();
if (key.equals(k)) {
return jObj.get(key);
}
if (jObj.get(key) instanceof JSONObject) {
Object probableKeyValue = find((JSONObject) jObj.get(key), k);
if(probableKeyValue != null){
return probableKeyValue;
}
}
if (jObj.get(key) instanceof JSONArray) {
JSONArray jar = (JSONArray) jObj.get(key);
for (int i = 0; i < jar.length(); i++) {
JSONObject j = jar.getJSONObject(i);
find(j, k);
}
}
}
return null;
}
I'm using Java, and I have a String which is JSON:
{
"name" : "abc" ,
"email id " : ["abc#gmail.com","def#gmail.com","ghi#gmail.com"]
}
Then my Map in Java:
Map<String, Object> retMap = new HashMap<String, Object>();
I want to store all the data from the JSONObject in that HashMap.
Can anyone provide code for this? I want to use the org.json library.
In recursive way:
public 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;
}
public 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;
}
Using Jackson library:
import com.fasterxml.jackson.databind.ObjectMapper;
Map<String, Object> mapping = new ObjectMapper().readValue(jsonStr, HashMap.class);
Using Gson, you can do the following:
Map<String, Object> retMap = new Gson().fromJson(
jsonString, new TypeToken<HashMap<String, Object>>() {}.getType()
);
Hope this will work, try this:
import com.fasterxml.jackson.databind.ObjectMapper;
Map<String, Object> response = new ObjectMapper().readValue(str, HashMap.class);
str, your JSON String
As Simple as this, if you want emailid,
String emailIds = response.get("email id").toString();
I just used Gson
HashMap<String, Object> map = new Gson().fromJson(json.toString(), HashMap.class);
Here is Vikas's code ported to JSR 353:
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import javax.json.JsonArray;
import javax.json.JsonException;
import javax.json.JsonObject;
public class JsonUtils {
public static Map<String, Object> jsonToMap(JsonObject json) {
Map<String, Object> retMap = new HashMap<String, Object>();
if(json != JsonObject.NULL) {
retMap = toMap(json);
}
return retMap;
}
public static Map<String, Object> toMap(JsonObject object) throws JsonException {
Map<String, Object> map = new HashMap<String, Object>();
Iterator<String> keysItr = object.keySet().iterator();
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) {
List<Object> list = new ArrayList<Object>();
for(int i = 0; i < array.size(); 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;
}
}
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import org.json.simple.JSONArray;
import org.json.simple.JSONObject;
public class JsonUtils {
public static Map<String, Object> jsonToMap(JSONObject json) {
Map<String, Object> retMap = new HashMap<String, Object>();
if(json != null) {
retMap = toMap(json);
}
return retMap;
}
public static Map<String, Object> toMap(JSONObject object) {
Map<String, Object> map = new HashMap<String, Object>();
Iterator<String> keysItr = object.keySet().iterator();
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) {
List<Object> list = new ArrayList<Object>();
for(int i = 0; i < array.size(); 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;
}
}
try this code :
Map<String, String> params = new HashMap<String, String>();
try
{
Iterator<?> keys = jsonObject.keys();
while (keys.hasNext())
{
String key = (String) keys.next();
String value = jsonObject.getString(key);
params.put(key, value);
}
}
catch (Exception xx)
{
xx.toString();
}
Latest Update: I have used FasterXML Jackson Databind2.12.3 to Convert JSON string to Map, Map to JSON string.
// javax.ws.rs.core.Response clientresponse = null; // Read JSON with Jersey 2.0 (JAX-RS 2.0)
// String json_string = clientresponse.readEntity(String.class);
String json_string = "[\r\n"
+ "{\"domain\":\"stackoverflow.com\", \"userId\":5081877, \"userName\":\"Yash\"},\r\n"
+ "{\"domain\":\"stackoverflow.com\", \"userId\":6575754, \"userName\":\"Yash\"}\r\n"
+ "]";
System.out.println("Input/Response JSON string:"+json_string);
ObjectMapper mapper = new com.fasterxml.jackson.databind.ObjectMapper();
//java.util.Map<String, String> map = mapper.readValue(json_string, java.util.Map.class);
List<Map<String, Object>> listOfMaps = mapper.readValue(json_string, new com.fasterxml.jackson.core.type.TypeReference< List<Map<String, Object>>>() {});
System.out.println("fasterxml JSON string to List of Map:"+listOfMaps);
String json = mapper.writeValueAsString(listOfMaps);
System.out.println("fasterxml List of Map to JSON string:[compact-print]"+json);
json = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(listOfMaps);
System.out.println("fasterxml List of Map to JSON string:[pretty-print]"+json);
output:
Input/Response JSON string:[
{"domain":"stackoverflow.com", "userId":5081877, "userName":"Yash"},
{"domain":"stackoverflow.com", "userId":6575754, "userName":"Yash"}
]
fasterxml JSON string to List of Map:[{domain=stackoverflow.com, userId=5081877, userName=Yash}, {domain=stackoverflow.com, userId=6575754, userName=Yash}]
fasterxml List of Map to JSON string:[compact-print][{"domain":"stackoverflow.com","userId":5081877,"userName":"Yash"},{"domain":"stackoverflow.com","userId":6575754,"userName":"Yash"}]
fasterxml List of Map to JSON string:[pretty-print][ {
"domain" : "stackoverflow.com",
"userId" : 5081877,
"userName" : "Yash"
}, {
"domain" : "stackoverflow.com",
"userId" : 6575754,
"userName" : "Yash"
} ]
Converting a JSON String to Map
public static java.util.Map<String, Object> jsonString2Map( String jsonString ) throws org.json.JSONException {
Map<String, Object> keys = new HashMap<String, Object>();
org.json.JSONObject jsonObject = new org.json.JSONObject( jsonString ); // HashMap
java.util.Iterator<?> keyset = jsonObject.keys(); // HM
while (keyset.hasNext()) {
String key = (String) keyset.next();
Object value = jsonObject.get(key);
System.out.print("\n Key : "+key);
if ( value instanceof org.json.JSONObject ) {
System.out.println("Incomin value is of JSONObject : ");
keys.put( key, jsonString2Map( value.toString() ));
} else if ( value instanceof org.json.JSONArray) {
org.json.JSONArray jsonArray = jsonObject.getJSONArray(key);
//JSONArray jsonArray = new JSONArray(value.toString());
keys.put( key, jsonArray2List( jsonArray ));
} else {
keyNode( value);
keys.put( key, value );
}
}
return keys;
}
Converting JSON Array to List
public static java.util.List<Object> jsonArray2List( org.json.JSONArray arrayOFKeys ) throws org.json.JSONException {
System.out.println("Incoming value is of JSONArray : =========");
java.util.List<Object> array2List = new java.util.ArrayList<Object>();
for ( int i = 0; i < arrayOFKeys.length(); i++ ) {
if ( arrayOFKeys.opt(i) instanceof org.json.JSONObject ) {
Map<String, Object> subObj2Map = jsonString2Map(arrayOFKeys.opt(i).toString());
array2List.add(subObj2Map);
} else if ( arrayOFKeys.opt(i) instanceof org.json.JSONArray ) {
java.util.List<Object> subarray2List = jsonArray2List((org.json.JSONArray) arrayOFKeys.opt(i));
array2List.add(subarray2List);
} else {
keyNode( arrayOFKeys.opt(i) );
array2List.add( arrayOFKeys.opt(i) );
}
}
return array2List;
}
public static Object keyNode(Object o) {
if (o instanceof String || o instanceof Character) return (String) o;
else if (o instanceof Number) return (Number) o;
else return o;
}
Display JSON of Any Format
public static void displayJSONMAP( Map<String, Object> allKeys ) throws Exception{
Set<String> keyset = allKeys.keySet(); // HM$keyset
if (! keyset.isEmpty()) {
Iterator<String> keys = keyset.iterator(); // HM$keysIterator
while (keys.hasNext()) {
String key = keys.next();
Object value = allKeys.get( key );
if ( value instanceof Map ) {
System.out.println("\n Object Key : "+key);
displayJSONMAP(jsonString2Map(value.toString()));
}else if ( value instanceof List ) {
System.out.println("\n Array Key : "+key);
JSONArray jsonArray = new JSONArray(value.toString());
jsonArray2List(jsonArray);
}else {
System.out.println("key : "+key+" value : "+value);
}
}
}
}
Google.gson to HashMap.
Convert using Jackson :
JSONObject obj = new JSONObject().put("abc", "pqr").put("xyz", 5);
Map<String, Object> map = new ObjectMapper().readValue(obj.toString(), new TypeReference<Map<String, Object>>() {});
You can convert any JSON to map by using Jackson library as below:
String json = "{\r\n\"name\" : \"abc\" ,\r\n\"email id \" : [\"abc#gmail.com\",\"def#gmail.com\",\"ghi#gmail.com\"]\r\n}";
ObjectMapper mapper = new ObjectMapper();
Map<String, Object> map = new HashMap<String, Object>();
// convert JSON string to Map
map = mapper.readValue(json, new TypeReference<Map<String, Object>>() {});
System.out.println(map);
Maven Dependencies for Jackson :
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-core</artifactId>
<version>2.5.3</version>
<scope>compile</scope>
</dependency>
<dependency>
<groupId>com.fasterxml.jackson.core</groupId>
<artifactId>jackson-databind</artifactId>
<version>2.5.3</version>
<scope>compile</scope>
</dependency>
Hope this will help. Happy coding :)
You can use Jackson API as well for this :
final String json = "....your json...";
final ObjectMapper mapper = new ObjectMapper();
final MapType type = mapper.getTypeFactory().constructMapType(
Map.class, String.class, Object.class);
final Map<String, Object> data = mapper.readValue(json, type);
If you hate recursion - using a Stack and javax.json to convert a Json String into a List of Maps:
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Stack;
import javax.json.Json;
import javax.json.stream.JsonParser;
public class TestCreateObjFromJson {
public static List<Map<String,Object>> extract(InputStream is) {
List extracted = new ArrayList<>();
JsonParser parser = Json.createParser(is);
String nextKey = "";
Object nextval = "";
Stack s = new Stack<>();
while(parser.hasNext()) {
JsonParser.Event event = parser.next();
switch(event) {
case START_ARRAY : List nextList = new ArrayList<>();
if(!s.empty()) {
// If this is not the root object, add it to tbe parent object
setValue(s,nextKey,nextList);
}
s.push(nextList);
break;
case START_OBJECT : Map<String,Object> nextMap = new HashMap<>();
if(!s.empty()) {
// If this is not the root object, add it to tbe parent object
setValue(s,nextKey,nextMap);
}
s.push(nextMap);
break;
case KEY_NAME : nextKey = parser.getString();
break;
case VALUE_STRING : setValue(s,nextKey,parser.getString());
break;
case VALUE_NUMBER : setValue(s,nextKey,parser.getLong());
break;
case VALUE_TRUE : setValue(s,nextKey,true);
break;
case VALUE_FALSE : setValue(s,nextKey,false);
break;
case VALUE_NULL : setValue(s,nextKey,"");
break;
case END_OBJECT :
case END_ARRAY : if(s.size() > 1) {
// If this is not a root object, move up
s.pop();
} else {
// If this is a root object, add ir ro rhw final
extracted.add(s.pop());
}
default : break;
}
}
return extracted;
}
private static void setValue(Stack s, String nextKey, Object v) {
if(Map.class.isAssignableFrom(s.peek().getClass()) ) ((Map)s.peek()).put(nextKey, v);
else ((List)s.peek()).add(v);
}
}
There’s an older answer using javax.json posted here, however it only converts JsonArray and JsonObject, but there are still JsonString, JsonNumber, and JsonValue wrapper classes in the output. If you want to get rid of these, here’s my solution which will unwrap everything.
Beside that, it makes use of Java 8 streams and is contained in a single method.
/**
* Convert a JsonValue into a “plain” Java structure (using Map and List).
*
* #param value The JsonValue, not <code>null</code>.
* #return Map, List, String, Number, Boolean, or <code>null</code>.
*/
public static Object toObject(JsonValue value) {
Objects.requireNonNull(value, "value was null");
switch (value.getValueType()) {
case ARRAY:
return ((JsonArray) value)
.stream()
.map(JsonUtils::toObject)
.collect(Collectors.toList());
case OBJECT:
return ((JsonObject) value)
.entrySet()
.stream()
.collect(Collectors.toMap(
Entry::getKey,
e -> toObject(e.getValue())));
case STRING:
return ((JsonString) value).getString();
case NUMBER:
return ((JsonNumber) value).numberValue();
case TRUE:
return Boolean.TRUE;
case FALSE:
return Boolean.FALSE;
case NULL:
return null;
default:
throw new IllegalArgumentException("Unexpected type: " + value.getValueType());
}
}
You can use google gson library to convert json object.
https://code.google.com/p/google-gson/
Other librarys like Jackson are also available.
This won't convert it to a map. But you can do all things which you want.
Brief and Useful:
/**
* #param jsonThing can be a <code>JsonObject</code>, a <code>JsonArray</code>,
* a <code>Boolean</code>, a <code>Number</code>,
* a <code>null</code> or a <code>JSONObject.NULL</code>.
* #return <i>Appropriate Java Object</i>, that may be a <code>Map</code>, a <code>List</code>,
* a <code>Boolean</code>, a <code>Number</code> or a <code>null</code>.
*/
public static Object jsonThingToAppropriateJavaObject(Object jsonThing) throws JSONException {
if (jsonThing instanceof JSONArray) {
final ArrayList<Object> list = new ArrayList<>();
final JSONArray jsonArray = (JSONArray) jsonThing;
final int l = jsonArray.length();
for (int i = 0; i < l; ++i) list.add(jsonThingToAppropriateJavaObject(jsonArray.get(i)));
return list;
}
if (jsonThing instanceof JSONObject) {
final HashMap<String, Object> map = new HashMap<>();
final Iterator<String> keysItr = ((JSONObject) jsonThing).keys();
while (keysItr.hasNext()) {
final String key = keysItr.next();
map.put(key, jsonThingToAppropriateJavaObject(((JSONObject) jsonThing).get(key)));
}
return map;
}
if (JSONObject.NULL.equals(jsonThing)) return null;
return jsonThing;
}
Thank #Vikas Gupta.
The following parser reads a file, parses it into a generic JsonElement, using Google's JsonParser.parse method, and then converts all the items in the generated JSON into a native Java List<object> or Map<String, Object>.
Note: The code below is based off of Vikas Gupta's answer.
GsonParser.java
import java.io.FileNotFoundException;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import com.google.gson.GsonBuilder;
import com.google.gson.JsonArray;
import com.google.gson.JsonElement;
import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.google.gson.JsonPrimitive;
public class GsonParser {
public static void main(String[] args) {
try {
print(loadJsonArray("data_array.json", true));
print(loadJsonObject("data_object.json", true));
} catch (Exception e) {
e.printStackTrace();
}
}
public static void print(Object object) {
System.out.println(new GsonBuilder().setPrettyPrinting().create().toJson(object).toString());
}
public static Map<String, Object> loadJsonObject(String filename, boolean isResource)
throws UnsupportedEncodingException, FileNotFoundException, JsonIOException, JsonSyntaxException, MalformedURLException {
return jsonToMap(loadJson(filename, isResource).getAsJsonObject());
}
public static List<Object> loadJsonArray(String filename, boolean isResource)
throws UnsupportedEncodingException, FileNotFoundException, JsonIOException, JsonSyntaxException, MalformedURLException {
return jsonToList(loadJson(filename, isResource).getAsJsonArray());
}
private static JsonElement loadJson(String filename, boolean isResource) throws UnsupportedEncodingException, FileNotFoundException, JsonIOException, JsonSyntaxException, MalformedURLException {
return new JsonParser().parse(new InputStreamReader(FileLoader.openInputStream(filename, isResource), "UTF-8"));
}
public static Object parse(JsonElement json) {
if (json.isJsonObject()) {
return jsonToMap((JsonObject) json);
} else if (json.isJsonArray()) {
return jsonToList((JsonArray) json);
}
return null;
}
public static Map<String, Object> jsonToMap(JsonObject jsonObject) {
if (jsonObject.isJsonNull()) {
return new HashMap<String, Object>();
}
return toMap(jsonObject);
}
public static List<Object> jsonToList(JsonArray jsonArray) {
if (jsonArray.isJsonNull()) {
return new ArrayList<Object>();
}
return toList(jsonArray);
}
private static final Map<String, Object> toMap(JsonObject object) {
Map<String, Object> map = new HashMap<String, Object>();
for (Entry<String, JsonElement> pair : object.entrySet()) {
map.put(pair.getKey(), toValue(pair.getValue()));
}
return map;
}
private static final List<Object> toList(JsonArray array) {
List<Object> list = new ArrayList<Object>();
for (JsonElement element : array) {
list.add(toValue(element));
}
return list;
}
private static final Object toPrimitive(JsonPrimitive value) {
if (value.isBoolean()) {
return value.getAsBoolean();
} else if (value.isString()) {
return value.getAsString();
} else if (value.isNumber()){
return value.getAsNumber();
}
return null;
}
private static final Object toValue(JsonElement value) {
if (value.isJsonNull()) {
return null;
} else if (value.isJsonArray()) {
return toList((JsonArray) value);
} else if (value.isJsonObject()) {
return toMap((JsonObject) value);
} else if (value.isJsonPrimitive()) {
return toPrimitive((JsonPrimitive) value);
}
return null;
}
}
FileLoader.java
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.io.UnsupportedEncodingException;
import java.net.MalformedURLException;
import java.net.URISyntaxException;
import java.net.URL;
import java.util.Scanner;
public class FileLoader {
public static Reader openReader(String filename, boolean isResource) throws UnsupportedEncodingException, FileNotFoundException, MalformedURLException {
return openReader(filename, isResource, "UTF-8");
}
public static Reader openReader(String filename, boolean isResource, String charset) throws UnsupportedEncodingException, FileNotFoundException, MalformedURLException {
return new InputStreamReader(openInputStream(filename, isResource), charset);
}
public static InputStream openInputStream(String filename, boolean isResource) throws FileNotFoundException, MalformedURLException {
if (isResource) {
return FileLoader.class.getClassLoader().getResourceAsStream(filename);
}
return new FileInputStream(load(filename, isResource));
}
public static String read(String path, boolean isResource) throws IOException {
return read(path, isResource, "UTF-8");
}
public static String read(String path, boolean isResource, String charset) throws IOException {
return read(pathToUrl(path, isResource), charset);
}
#SuppressWarnings("resource")
protected static String read(URL url, String charset) throws IOException {
return new Scanner(url.openStream(), charset).useDelimiter("\\A").next();
}
protected static File load(String path, boolean isResource) throws MalformedURLException {
return load(pathToUrl(path, isResource));
}
protected static File load(URL url) {
try {
return new File(url.toURI());
} catch (URISyntaxException e) {
return new File(url.getPath());
}
}
private static final URL pathToUrl(String path, boolean isResource) throws MalformedURLException {
if (isResource) {
return FileLoader.class.getClassLoader().getResource(path);
}
return new URL("file:/" + path);
}
}
If you want no-lib version, here is the solution with regex:
public static HashMap<String, String> jsonStringToMap(String inputJsonString) {
final String regex = "(?:\\\"|\\')(?<key>[\\w\\d]+)(?:\\\"|\\')(?:\\:\\s*)(?:\\\"|\\')?(?<value>[\\w\\s-]*)(?:\\\"|\\')?";
HashMap<String, String> map = new HashMap<>();
final Pattern pattern = Pattern.compile(regex, Pattern.MULTILINE);
final Matcher matcher = pattern.matcher(inputJsonString);
while (matcher.find()) {
for (int i = 1; i <= matcher.groupCount(); i++) {
map.put(matcher.group("key"), matcher.group("value"));
}
}
return map;
}
Imagine u have a list of email like below. not constrained to any programming language,
emailsList = ["abc#gmail.com","def#gmail.com","ghi#gmail.com"]
Now following is JAVA code - for converting json to map
JSONObject jsonObj = new JSONObject().put("name","abc").put("email id",emailsList);
Map<String, Object> s = jsonObj.getMap();
This is an old question and maybe still relate to someone.
Let's say you have string HashMap hash and JsonObject jsonObject.
1) Define key-list.
Example:
ArrayList<String> keyArrayList = new ArrayList<>();
keyArrayList.add("key0");
keyArrayList.add("key1");
2) Create foreach loop, add hash from jsonObject with:
for(String key : keyArrayList){
hash.put(key, jsonObject.getString(key));
}
That's my approach, hope it answer the question.
Using json-simple you can convert data JSON to Map and Map to JSON.
try
{
JSONObject obj11 = new JSONObject();
obj11.put(1, "Kishan");
obj11.put(2, "Radhesh");
obj11.put(3, "Sonal");
obj11.put(4, "Madhu");
Map map = new HashMap();
obj11.toJSONString();
map = obj11;
System.out.println(map.get(1));
JSONObject obj12 = new JSONObject();
obj12 = (JSONObject) map;
System.out.println(obj12.get(1));
}
catch(Exception e)
{
System.err.println("EROR : 01 :"+e);
}