creating Hashmap from a JSON String

creating a hashmap from a json string in java?

I have json string like {"phonetype":"N95","cat":"WP"} and want to convert into a standard Hashmap.

How can i do it?


Parse the JSONObject and create HashMap

public static void jsonToMap(String t) throws JSONException {

        HashMap<String, String> map = new HashMap<String, String>();
        JSONObject jObject = new JSONObject(t);
        Iterator<?> keys = jObject.keys();

        while( keys.hasNext() ){
            String key = (String)keys.next();
            String value = jObject.getString(key); 
            map.put(key, value);

        }

        System.out.println("json : "+jObject);
        System.out.println("map : "+map);
    }

Tested output:

json : {"phonetype":"N95","cat":"WP"}
map : {cat=WP, phonetype=N95}

You can use Google's Gson library to convert json to Hashmap. Try below code

String jsonString = "Your JSON string";
HashMap<String,String> map = new Gson().fromJson(jsonString, new TypeToken<HashMap<String, String>>(){}.getType());

public class JsonMapExample {

    public static void main(String[] args) {
        String json = "{\"phonetype\":\"N95\",\"cat\":\"WP\"}";
        Map<String, String> map = new HashMap<String, String>();
        ObjectMapper mapper = new ObjectMapper();

        try {
            //convert JSON string to Map
            map = mapper.readValue(json, new TypeReference<HashMap<String, String>>() {});
            System.out.println(map);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}

Output:

{phonetype=N95, cat=WP}

You can see this link it's helpful http://www.mkyong.com/java/how-to-convert-java-map-to-from-json-jackson/


You could use Gson library

Type type = new TypeToken<HashMap<String, String>>() {}.getType();
new Gson().fromJson(jsonString, type);