How to prevent openConnection() to actually connec

问题:

I want to use HttpURLConnection to connect to my webservice, POST an XML and get a result. I am using the following code:

URL url = new URL(urlString);
connection = (HttpURLConnection)url.openConnection();
connection.setRequestProperty("Content-Type", "text/xml; charset=utf-8");

Problem is, when I call the setRequestProperty method, it fails with an IllegalStateException saying I am "already connected". Apparently, openConnection in fact opens the connection to the URL (in my debugger, I can see the connected boolean set to true). According to the URL documentation of Oracle though, it shouldn't. The Android docs are unclear about it.

How do I prevent openConnection to connect, so I can set extra properties?

Update it looks like the connection is in some pool and doesn't get disconnected, not even after calling connection.disconnect(), or even killing the server.

I do not think this is a duplicate of this question as it gives no real answer. Also, the documentation seems to be unclear.

回答1:

openConnection() does not connect, and the code you have posted does not behave as yu have described. What opens the TCP connection is any of the following:

• getInputStream()
• getErrorStream()
• getResponseCode()

Ergo you must have called one of those before trying to set a request property.