Adding header for HttpURLConnection

To add a header to an HTTP request using HttpURLConnection, you can use the setRequestProperty method. This method takes a string key and a string value, and adds a new header to the request with the specified key and value. Here's an example of how you can use setRequestProperty to add a "Content-Type" header to an HTTP request:

URL url = new URL("http://www.example.com");
HttpURLConnection connection = (HttpURLConnection) url.openConnection();
connection.setRequestMethod("POST");
connection.setRequestProperty("Content-Type", "application/json");

You can also add multiple headers to the same request by calling setRequestProperty multiple times.

connection.setRequestProperty("Header1", "value1");
connection.setRequestProperty("Header2", "value2");