如何从 FLASK 中的 GET 请求中获取 Json 对象

Question

我的服务器是 flask，我的客户端是 javascript，我正在使用 jquery - ajax 向服务器发送数据。我能够从 POST 请求中获取 JSON 对象，但无法通过 GET 获取。

来自 Javascript 客户的请求：

$.ajax({type: 'GET',
        url: "/checkForTrain",
        data: jsonObj,
        success: function(response){
            response = JSON.parse(response)
            if(response['status']==='success')
                postDataset(data)
            else
                handleError(data)
        },
        error :   function(response){
            console.log(response)
        }
    })

url 在 flask 中处理请求：

@app.route('/checkForTrain',methods=['GET','OPTIONS'])
def checkForTrain():
    print request
    json_str=u''+str(request.get_data())
    print json_str,' <--- json data'
    dataSearch = json.loads(json_str)
    print dataSearch,' <--- dictionary'
    obj = dbWrapper.checkForTrain(dataSearch['name'],dataSearch['type'])
    return obj

打印请求的输出：

<Request 'http://localhost:5000/checkForTrain?{"name":"lel","technique":"regression"}' [GET]>

打印输出json_str,'<--- json数据'

<--- json data

服务器的堆栈跟踪：

Traceback (most recent call last):
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1836, in __call__
    return self.wsgi_app(environ, start_response)
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1820, in wsgi_app
    response = self.make_response(self.handle_exception(e))
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1403, in handle_exception
    reraise(exc_type, exc_value, tb)
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1817, in wsgi_app
    response = self.full_dispatch_request()
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1477, in full_dispatch_request
    rv = self.handle_user_exception(e)
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1381, in handle_user_exception
    reraise(exc_type, exc_value, tb)
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1475, in full_dispatch_request
    rv = self.dispatch_request()
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/lib/python2.7/site-packages/flask/app.py", line 1461, in dispatch_request
    return self.view_functions[rule.endpoint](**req.view_args)
  File "/home/adminuser/Desktop/Github/DataMining/DataMiningProject/app/routes.py", line 53, in checkForTrain
    dataSearch = json.loads(json_str)
  File "/usr/lib/python2.7/json/__init__.py", line 338, in loads
    return _default_decoder.decode(s)
  File "/usr/lib/python2.7/json/decoder.py", line 366, in decode
    obj, end = self.raw_decode(s, idx=_w(s, 0).end())
  File "/usr/lib/python2.7/json/decoder.py", line 384, in raw_decode
    raise ValueError("No JSON object could be decoded")

Answer 1

您需要提取查询字符串；你可以使用 request.query_string attribute to access it; you'll have to manually unquote 它：

From urllib import unquote

json_str = unquote(request.query_string)

然后你的视图输出：

<Request 'http://localhost:5000/checkForTrain?{"name":"lel","technique":"regression"}' [GET]>
{"name":"lel","technique":"regression"}  <--- json data
{u'technique': u'regression', u'name': u'lel'}  <--- dictionary

request.get_data() method只能用于访问请求正文，而GET请求永远不会有正文。

如果您的数据仅由键值对组成，那么坚持对这些键值对进行表单编码可能更容易，并坚持使用 Flask 的 request.args 功能，而不是在这里使用 JSON。

如何从 FLASK 中的 GET 请求中获取 Json 对象

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