【发布时间】：2021-04-13 03:22:14
【问题描述】：
我正在使用 js 客户端和服务器端 (python) 编写简单的网站，我尽一切努力消除 CORS 错误，但没有任何效果。我为此编写了所有需要的标题，但仍然出现此错误。所以网站应该向服务器发送请求并获得答案。 错误：
Access to XMLHttpRequest at 'http://127.0.0.1:8000/' from origin 'null' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.
我的文件.html：
<!DOCTYPE html>
<html>
<head>
<title>requestJs</title>
</head>
<body>
<button class="myButton">SEND</button>
<script type="text/javascript">
let theButton = document.querySelector(".myButton");
theButton.addEventListener('click',function() {
const xhr = new XMLHttpRequest();
xhr.onload = function() {
alert(`Статус: ${xhr.status}; Результат: ${xhr.response}`)
};
xhr.onerror = function() {
alert('Ошибка запроса');
};
xhr.open("GET", "http://127.0.0.1:8000/", true);
xhr.send(2);
})
</script>
</body>
</html>
服务器端：
import http.server as httpserver
class CORSHTTPRequestHandler(httpserver.SimpleHTTPRequestHandler):
def send_head(self):
"""Common code for GET and HEAD commands.
This sends the response code and MIME headers.
Return value is either a file object (which has to be copied
to the outputfile by the caller unless the command was HEAD,
and must be closed by the caller under all circumstances), or
None, in which case the caller has nothing further to do.
"""
path = self.translate_path(self.path)
f = None
if os.path.isdir(path):
if not self.path.endswith('/'):
# redirect browser - doing basically what apache does
self.send_response(301)
self.send_header("Location", self.path + "/")
self.end_headers()
return None
for index in "index.html", "index.html":
index = os.path.join(path, index)
if os.path.exists(index):
path = index
break
else:
return self.list_directory(path)
ctype = self.guess_type(path)
try:
# Always read in binary mode. Opening files in text mode may cause
# newline translations, making the actual size of the content
# transmitted *less* than the content-length!
f = open(path, 'rb')
except IOError:
self.send_error(404, "File not found")
return None
self.send_response(200)
self.send_header("Content-type", ctype)
fs = os.fstat(f.fileno())
self.send_header("Content-Length", str(fs[6]))
self.send_header("Last-Modified", self.date_time_string(fs.st_mtime))
self.send_header("Access-Control-Allow-Origin:", "*")
self.send_header("Access-Control-Allow-Methods:", "GET,HEAD,PUT,PATCH,POST,DELETE")
self.send_header("Access-Control-Allow-Headers:", "Content-Type, Access-Control-Allow-Origin, xxx")
self.end_headers()
return f
if __name__ == "__main__":
import os
import socketserver
import sys
PORT = int(sys.argv[1]) if len(sys.argv) > 1 else 8000
handler = CORSHTTPRequestHandler
httpd = socketserver.TCPServer(("", PORT), handler)
print(f"serving at port {PORT}")
httpd.serve_forever()
请帮帮我，我的问题是什么？
【问题讨论】：
-
你检查过为什么你的网站的来源是
null吗？您能否确认响应包含您设置的所有标头？ -
你确定
self.send_header("Access-Control-Allow-Origin:", "*")不应该是self.send_header("Access-Control-Allow-Origin", "*")吗？ -
@acincognito 我按照你的说法更改了标题，但我不明白这个关于 origin: null 的事情，你能解释一下这是什么意思以及我应该添加哪些标题？我必须在js请求中添加标头吗？
-
见Access-Control-Allow-Headers。我想知道你是否应该不指定这个。
-
@Booboo 谢谢你会读到的。顺便说一句，有没有办法根本不面对cors？因为我不认为每个网站都这样做。我猜他们出现是有特殊原因的
标签： javascript python ajax cors