java - Convert JSONObject to HashMap

Question

I have a JSONObject structured like this:

"data": {
   "title": "Pool Party",
   "date": {
       "start": "2018-08-14T15:44:44.625Z",
       "end": "2018-08-14T18:44:44.625Z"
}

and I'd like to convert it to

HashMap<String, String>

is there a way to structure the map in the same way for what regards the "start" and "end" field, which are under the "date" field?

I tried to convert it using Gson like this:

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

but I got this error:

com.google.gson.JsonSyntaxException: java.lang.IllegalStateException: Expected a string but was BEGIN_OBJECT

probably because of the structure of my JSON string

Is there a way to get something like this? Thank you for your help.

Duplicate question Here already given a solution [solution](https://stackoverflow.com/questions/2525042/how-to-convert-a-json-string-to-a-mapstring-string-with-jackson-json) — Himly, Aug 29 '18 at 01:36

Himly · Answer 1 · 2018-08-29T01:50:09.573

1

You can use the ObjectMapper to convert it.

public void testJackson() throws IOException {  
    ObjectMapper mapper = new ObjectMapper(); 
    String json = "{"data": {"title": "Pool Party","date": {"start": "2018-08-14T15:44:44.625Z", "end": "2018-08-14T18:44:44.625Z"}}}"; 
    TypeReference<HashMap<String,Object>> typeRef 
            = new TypeReference<HashMap<String,Object>>() {};

    HashMap<String,Object> o = mapper.readValue(from, typeRef); 
    System.out.println("Got " + o); 
}

edited Aug 29 '18 at 01:50

answered Aug 29 '18 at 01:41

Himly

384
2
16

But I need it to be converted to HashMap not HashMap – Mantech Aug 29 '18 at 01:52

score 0 · Answer 2 · edited Aug 29 '18 at 04:37

try something like this:

public void testJackson() throws IOException {
    ObjectMapper mapper = new ObjectMapper();
    String json = "{\"data\": {\"title\": \"Pool Party\",\"date\": {\"start\":\"2018-08-14T15:44:44.625Z\", \"end\":\"2018-08-14T18:44:44.625Z\"}}}";
    TypeReference<HashMap<String, Object>> typeRef = new TypeReference<HashMap<String, Object>>() {
    };
    HashMap<String, Object> o = mapper.readValue(from, typeRef);
    System.out.println("Got " + o);
}

java - Convert JSONObject to HashMap

2 Answers2