问题
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);
}
回答1:
Instead of
return new ResponseEntity<JSONObject>(entities, HttpStatus.OK);
try
return new ResponseEntity<List<JSONObject>>(entities, HttpStatus.OK);
回答2:
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);
}
回答3:
Personally, I prefer changing the method signature to:
public ResponseEntity<?>
This gives the advantage of possibly returning an error message as single item for services which, when ok, return a list of items.
When returning I don't use any type (which is unused in this case anyway):
return new ResponseEntity<>(entities, HttpStatus.OK);
来源:https://stackoverflow.com/questions/26320106/spring-return-responsebody-responseentitylistjsonobject