CODEWITHSUNDEEP
javajsondictionary
Vikas Gupta
Vikas Gupta

Reputation: 10904

Convert a JSON String to a HashMap

I'm using Java, and I have a String which is JSON:

{
"name" : "abc" ,
"email id " : ["[email protected]","[email protected]","[email protected]"]
}

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.

Upvotes: 215

Views: 567531

Answers (21)

Philippe
Philippe

Reputation: 101

Here's a solution using a switch expression.

static Map<String, Object> jsonToMap(Reader reader) {
  var jsonReader = Json.createReader(reader);
  var jsonValue = jsonReader.readValue(); // Removes duplicate keys (last one wins)
  @SuppressWarnings("unchecked")
  var map = (Map<String, Object>) jsonValueToObject(jsonValue);
  return map;
}

private static Object jsonValueToObject(JsonValue value) {
  return switch (value.getValueType()) {
    case OBJECT -> ((JsonObject) value).entrySet().parallelStream().collect(
        HashMap::new,
        (map, entry) -> map.put(entry.getKey(), jsonValueToObject(entry.getValue())),
        (map1, map2) -> map2.entrySet().forEach(entry -> map1.put(entry.getKey(), entry.getValue())));
    case ARRAY -> ((JsonArray) value).stream().map(Utils::jsonValueToObject).collect(toList());
    case STRING -> ((JsonString) value).getString();
    case NUMBER -> ((JsonNumber) value).numberValue();
    case TRUE -> Boolean.TRUE;
    case FALSE -> Boolean.FALSE;
    default -> null; // Only JsonValue.NULL remains
  };
}

I didn't use the Collectors.toMap() collector, because it doesn't allow null values.

Upvotes: 0

rgaraisayev
rgaraisayev

Reputation: 396

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;
}

Upvotes: 0

Vikas Gupta
Vikas Gupta

Reputation: 10904

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);

Upvotes: 256

Yash
Yash

Reputation: 9568

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.

Upvotes: 8

Toon Borgers
Toon Borgers

Reputation: 3658

Using Gson, you can do the following:

Map<String, Object> retMap = new Gson().fromJson(
    jsonString, new TypeToken<HashMap<String, Object>>() {}.getType()
);

Upvotes: 184

qqilihq
qqilihq

Reputation: 11454

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());
    }
}

Upvotes: 3

Parameshwar
Parameshwar

Reputation: 966

I just used Gson

HashMap<String, Object> map = new Gson().fromJson(json.toString(), HashMap.class);

Upvotes: 17

Abhishek Pandey
Abhishek Pandey

Reputation: 97

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>>() {});

Upvotes: 7

Muchtarpr
Muchtarpr

Reputation: 97

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.

Upvotes: -1

hareluya86
hareluya86

Reputation: 181

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);
    }
}

Upvotes: 2

13hola
13hola

Reputation: 170

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);
}

Upvotes: -3

Mir-Ismaili
Mir-Ismaili

Reputation: 16928

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.

Upvotes: 1

Abhijith Anil
Abhijith Anil

Reputation: 119

Imagine u have a list of email like below. not constrained to any programming language,

emailsList = ["[email protected]","[email protected]","[email protected]"]

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();

Upvotes: -1

MukilanKarthikeyan
MukilanKarthikeyan

Reputation: 671

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();

Upvotes: 67

Osama Ibrahim
Osama Ibrahim

Reputation: 1021

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();
                }

Upvotes: 7

Ankur Mahajan
Ankur Mahajan

Reputation: 3586

You can convert any JSON to map by using Jackson library as below:

String json = "{\r\n\"name\" : \"abc\" ,\r\n\"email id \" : [\"[email protected]\",\"[email protected]\",\"[email protected]\"]\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 :)

Upvotes: 5

Swapnil Jaju
Swapnil Jaju

Reputation: 472

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);

Upvotes: 3

Ashish Garg
Ashish Garg

Reputation: 89

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;
    }
}

Upvotes: 7

Mr. Polywhirl
Mr. Polywhirl

Reputation: 48600

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);
    }
}

Upvotes: 0

Kolban
Kolban

Reputation: 15246

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;
    }
}

Upvotes: 9

Konza
Konza

Reputation: 2163

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.

Upvotes: 1

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