Flutter/Dart前端与Go后端POST请求问题及Cookie存储疑问

Hey there! Let's break down your two issues one by one to get you sorted out.

Since your Go backend specifically checks for a Cookie named session, you need to make sure when you send subsequent GET requests, the request header includes the full key-value pair in the correct Cookie format. Here's what to do:

• When you receive the Set-Cookie header from the backend (it’ll look something like session=your-uuid-here; Path=/; HttpOnly), you can either:
  1. Save the entire session=your-uuid-here string directly. Then, when making GET requests, add a header like Cookie: [saved-string] to your request.
  2. Save the key (session) and value (your-uuid-here) separately. When sending the request, construct the header value as session=your-uuid-here and add it to the Cookie header.
     Either way works, but the critical part is that the backend sees a Cookie named session with the correct UUID value. Don’t just save the UUID alone—without the session= prefix, the backend won’t recognize it as the right Cookie.

Your guess about missing JSON data is spot-on! Here’s why this happens:

• When you visit localhost:8080 directly in a browser, it sends a GET request with no request body. But your login endpoint probably expects a POST request with a JSON payload (like {"username":"your-username","password":"your-password"}).
• Go’s JSON parser throws an EOF error when it tries to read a request body that doesn’t exist.

To fix this:

• Use a tool like Postman or curl to send a proper POST request to your login endpoint. Make sure to set the Content-Type header to application/json and include the required JSON body with your login credentials.
• If you want the browser to handle it, you’ll need to create a simple HTML form that sends a POST request with JSON data (or adjust your Go backend to accept GET requests for the login endpoint, though that’s not recommended for security reasons).

内容的提问来源于stack exchange，提问作者DanT29