从JSON字符串创建Hashmap

Question

从java中的json字符串创建hashmap？

我有类似于{"phonetype":"N95","cat":"WP"}的json字符串，并且希望转换成一个标准的Hashmap。

我该怎么做呢？

Answer 1

解析JSONObject并创建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);
    }

经测试的产出：

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

Answer 2

您可以使用Google的Gson库将json转换为Hashmap。试试下面的代码

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

Answer 3

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();
        }
    }
}

输出：

{phonetype=N95, cat=WP}

你可以看到这个链接它很有用的http://www.mkyong.com/java/how-to-convert-java-map-to-from-json-jackson/