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用python的Flask写的服务器，web用jquery的ajax请求时候报这个错。
官方文档给的说明在这里http://flask.pocoo.org/snippets/56/
简单点说就是在启动app的地方加上一个装饰器@crossdomain(origin='*')
from flask import Flask
app = Flask(__name__)
@app.route("/")
@crossdomain(origin='*')
def hello():
return "Hello World!"
if __name__ == "__main__":
app.run()
具体的装饰器实现代码也要复制进去
from datetime import timedelta
from flask import make_response, request, current_app
from functools import update_wrapper
def crossdomain(origin=None, methods=None, headers=None,
max_age=21600, attach_to_all=True,
automatic_options=True):
if methods is not None:
methods = ', '.join(sorted(x.upper() for x in methods))
if headers is not None and not isinstance(headers, basestring):
headers = ', '.join(x.upper() for x in headers)
if not isinstance(origin, basestring):
origin = ', '.join(origin)
if isinstance(max_age, timedelta):
max_age = max_age.total_seconds()
def get_methods():
if methods is not None:
return methods
options_resp = current_app.make_default_options_response()
return options_resp.headers['allow']
def decorator(f):
def wrapped_function(*args, **kwargs):
if automatic_options and request.method == 'OPTIONS':
resp = current_app.make_default_options_response()
else:
resp = make_response(f(*args, **kwargs))
if not attach_to_all and request.method != 'OPTIONS':
return resp
h = resp.headers
h['Access-Control-Allow-Origin'] = origin
h['Access-Control-Allow-Methods'] = 'GET,POST,PUT,DELETE'
h['Access-Control-Max-Age'] = str(max_age)
if headers is not None:
h['Access-Control-Allow-Headers'] = headers
return resp
f.provide_automatic_options = False
return update_wrapper(wrapped_function, f)
return decorator
完整代码如下
from datetime import timedelta
from flask import make_response, request, current_app
from functools import update_wrapper
def crossdomain(origin=None, methods=None, headers=None,
max_age=21600, attach_to_all=True,
automatic_options=True):
if methods is not None:
methods = ', '.join(sorted(x.upper() for x in methods))
if headers is not None and not isinstance(headers, basestring):
headers = ', '.join(x.upper() for x in headers)
if not isinstance(origin, basestring):
origin = ', '.join(origin)
if isinstance(max_age, timedelta):
max_age = max_age.total_seconds()
def get_methods():
if methods is not None:
return methods
options_resp = current_app.make_default_options_response()
return options_resp.headers['allow']
def decorator(f):
def wrapped_function(*args, **kwargs):
if automatic_options and request.method == 'OPTIONS':
resp = current_app.make_default_options_response()
else:
resp = make_response(f(*args, **kwargs))
if not attach_to_all and request.method != 'OPTIONS':
return resp
h = resp.headers
h['Access-Control-Allow-Origin'] = origin
h['Access-Control-Allow-Methods'] = get_methods()
h['Access-Control-Max-Age'] = str(max_age)
if headers is not None:
h['Access-Control-Allow-Headers'] = headers
return resp
f.provide_automatic_options = False
return update_wrapper(wrapped_function, f)
return decorator
from flask import Flask
app = Flask(__name__)
@app.route("/")
@crossdomain(origin='*')
def hello():
return "Hello World!"
if __name__ == "__main__":
app.run()
上述方法虽然可行，但是不够完善，经昊宇大神点播，采用以下办法更合适
# -*- coding:utf-8 -*-
from flask import Flask, request
import json
def after_request(response):
response.headers['Access-Control-Allow-Origin'] = '*'
response.headers['Access-Control-Allow-Methods'] = 'PUT,GET,POST,DELETE'
response.headers['Access-Control-Allow-Headers'] = 'Content-Type,Authorization'
return response
def create_app():
app = Flask(__name__)
app.after_request(after_request)