martin martin - 1 month ago 3
Java Question

Spring: return @ResponseBody "ResponseEntity<List<JSONObject>>"

In controller I create json array. If I return

List<JSONObject>
it is ok:

@RequestMapping(value="", method=RequestMethod.GET, produces=MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody List<JSONObject> getAll() {
List<Entity> entityList = entityManager.findAll();

List<JSONObject> entities = new ArrayList<JSONObject>();
for (Entity n : entityList) {
JSONObject entity = new JSONObject();
entity.put("id", n.getId());
entity.put("address", n.getAddress());
entities.add(entity);
}
return entities;
}


but I need to return JSON array and HTTP status code:

@RequestMapping(value="", method=RequestMethod.GET, produces=MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody ResponseEntity<List<JSONObject>> getAll() {
List<Entity> entityList = entityManager.findAll();

List<JSONObject> entities = new ArrayList<JSONObject>();
for (Entity n : entityList) {
JSONObject Entity = new JSONObject();
entity.put("id", n.getId());
entity.put("address", n.getAddress());
entities.add(entity);
}
return new ResponseEntity<JSONObject>(entities, HttpStatus.OK); // XXX
}


Eclipse see error in XXX line:

Multiple markers at this line
- The constructor ResponseEntity<JSONObject>(List<JSONObject>, HttpStatus) is undefined
- Type mismatch: cannot convert from ResponseEntity<JSONObject> to
ResponseEntity<List<JSONObject>>
- Type mismatch: cannot convert from ResponseEntity<JSONObject> to JSONObject


How can I return json+http reply? There is my working code for returning one json object + http status code:

@RequestMapping(value="/{address}", method=RequestMethod.GET, produces=MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody ResponseEntity<JSONObject> getEntity(@PathVariable("address") int address) {
Entity n = entityManager.findByAddress(address);
JSONObject o = new JSONObject();
o.put("id", n.getId());
o.put("address", n.getAddress());
return new ResponseEntity<JSONObject>(o, HttpStatus.OK);
}

Answer

Now I return Object. I don't know better solution, but it works.

@RequestMapping(value="", method=RequestMethod.GET, produces=MediaType.APPLICATION_JSON_VALUE)
public @ResponseBody ResponseEntity<Object> getAll() {
    List<Entity> entityList = entityManager.findAll();

    List<JSONObject> entities = new ArrayList<JSONObject>();
    for (Entity n : entityList) {
        JSONObject Entity = new JSONObject();
        entity.put("id", n.getId());
        entity.put("address", n.getAddress());
        entities.add(entity);
    }
    return new ResponseEntity<Object>(entities, HttpStatus.OK);
}
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