springboot设置响应状态码

使用HttpServletResponse对象直接设置状态局限比较大，可以改用以下方式，通过ResponseEntity可以返回我们需要的数据还可以自定义状态码。

    @RequestMapping("/oauth/token")
    public ResponseEntity<Object> token(@RequestParam(value="grant_type",required=false)String grant_type,
            @RequestParam(value="client_id",required=false)String client_id,
            @RequestParam(value="client_secret",required=false)String client_secret){
        OauthError error=new OauthError();
        AccessTokenResponse tokenResponse=new AccessTokenResponse();
        if(grant_type==null||client_id==null||client_secret==null){
            error.setError(ResponseErrorEnum.INVALID_REQUEST.getError());
            error.setError_description(ResponseErrorEnum.INVALID_REQUEST.getError_description());
            return new ResponseEntity<Object>(error,HttpStatus.OK);
        }
        if(GrantTypeEnum.getGrantTypeEnumByCode(grant_type)==null){
            error.setError(ResponseErrorEnum.UNSUPPORTED_GRANT_TYPE.getError());
            error.setError_description(ResponseErrorEnum.UNSUPPORTED_GRANT_TYPE.getError_description());
            return new ResponseEntity<Object>(error,HttpStatus.OK);
        }
        if(grant_type.equals(GrantTypeEnum.CLIENT_CREDENTIALS.getCode())){
            tokenResponse=oauthService.clientCredentials(client_id, client_secret);
            if(tokenResponse==null){
                error.setError(ResponseErrorEnum.INVALID_CLIENT.getError());
                error.setError_description(ResponseErrorEnum.INVALID_CLIENT.getError_description());
                return new ResponseEntity<Object>(error,HttpStatus.UNAUTHORIZED);
            }
            
        }
        return new ResponseEntity<Object>(tokenResponse,HttpStatus.OK);
    }