如何从URLConnection删除标头

Question

I am talking to a file upload service that accepts post data, not form data. By default, java's HttpURLConnection sets the Content-Type header to application/x-www-form-urlencoded . this is obviously wrong if i'm posting pure data.

I (the client) don't know the content type. I don't want the Content-Type header set at all. the service has a feature where it will guess at the content type (based on the file name, reading some data from the file, etc).

How do I unset a header? There's no remove header, and setting it to null doesn't change the value and setting it to the empty string results in the header being set with no value.

Answer 1

Use Apache HttpClient instead of URLConnection

Use fluent Request to generate your request

use removeHeader()

Answer 2

I haven't tested this approach but you can try this:

Extend HttpURLConnection and try by overriding its getContentHandler() and setContentHandler(...) methods. Most probably this should work as, you will take a look at code of getContentHandler().

Answer 3

What do you mean "i don't want the Content-Type header to set at all"?

The browser (or other http client) sends your post request to the server, so it has to inform the server which way it encoded the parameters.

If the Content-Type header is not set, on the server side you (= your server) won't be able to understand how to parse the received data.

If you didn't set Content-Type, the default value will be used.

You browser (or other http client) MUST do two things:

1. Send key/value pairs.
2. Inform the server how the key/value pairs were encoded.

So, it is impossible to completely get rid of this header.

Answer 4

我只是通过将标头设置为null来完成此操作。

connection.setRequestProperty(MY_HEADER, null);