Question

I want to know that what is url encoding.
I have 2 jsp pages and one servlet.
When I run the application the url displayed is :

http://localhost:8080/myproject/index.jsp

where

index.jsp :

<form action="Myservlet" method="post">
    <input type="text" name="mytext" id="mytext"/>
    <input type="submit" value="submit"/>
</form>

after the submit button is clicked the URL displayed is :

http://localhost:8080/myproject/Myservlet

What is the meaning of URL encoding? How can I encode url?

From index.jsp goes to Myservlet then to result.jsp

Myservet#doPost // Do I need to do URL encoding here? If yes how ?

  fetching data from db.......
  ....................
  String nextJSP = "/result.jsp";
  RequestDispatcher dispatcher = getServletContext().getRequestDispatcher(nextJSP);
  dispatcher.forward(request,response);

result.jsp

displays data here

Answer 1

There are two types of encoding: HTML form encoding and URL re-writing.

In form encoding, the URL string is converted into a valid ASCII format that’s Internet-ready. From the URLEncoder.encode(String, String) docs:

Translates a string into application/x-www-form-urlencoded format
using a specific encoding scheme. This method uses the supplied
encoding scheme to obtain the bytes for unsafe characters.

The second kind is URL rewriting. The URL string is encoded with a session id in case the client browser doesn’t support (or has disabled) cookies or session tracking. From the HttpServletResponse.encodeURL(String) docs:

Encodes the specified URL by including the session ID in it, or, if
encoding is not needed, returns the URL unchanged. The implementation
of this method includes the logic to determine whether the session ID
needs to be encoded in the URL. For example, if the browser supports
cookies, or session tracking is turned off, URL encoding is
unnecessary.