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

Question

在控制器中我创建了json数组.如果我退货List<JSONObject>就可以了:

@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;
}

但我需要返回JSON数组和HTTP状态代码:

@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在XXX行中看到错误:

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

我怎样才能返回json + http回复？有我的工作代码返回一个json对象+ http状态代码:

@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 1

代替

return new ResponseEntity<JSONObject>(entities, HttpStatus.OK);

尝试

return new ResponseEntity<List<JSONObject>>(entities, HttpStatus.OK);

Answer 2

现在我回来了Object.我不知道更好的解决方案,但它确实有效.

@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);
}

Answer 3

就个人而言,我更喜欢将方法签名更改为:

public ResponseEntity<?>

这提供了可能将错误消息作为服务的单个项目返回的优点,当确定时,返回项目列表.

返回时我不使用任何类型(在这种情况下未使用):

return new ResponseEntity<>(entities, HttpStatus.OK);