Response does not implement http.Hijacker

Question

I\'m using Go and trying to implement WebSocket in my project. while implementing this. I get "WebSocket: response does not implement HTTP.Hijacker" error. I\'m ne

Answer 1

The application is using "middleware" that wraps the net/http server's ResponseWriter implementation. The middleware wrapper does not implement the Hijacker interface.

There are two fixes for the problem:

• Remove the offending middleware.

• Implement the Hijacker interface on the middleware wrapper by delegating through to the underlying response. The method implementation will look something like this:

  func (w *wrapper) Hijack() (net.Conn, *bufio.ReadWriter, error) {
      h, ok := w.underlyingResponseWriter.(http.Hijacker)
      if !ok {
          return nil, nil, errors.New("hijack not supported")
      }
      return h.Hijack()
  }
  

If you don't know what the response writer wrapper is, add a statement to print the type from the handler:

func HandleConnections(w http.ResponseWriter, r *http.Request) {
    fmt.Printf("w's type is %T\n", w)
    ...