Question

I’m building a web app for my lesson using java servlets. At some point i want to redirect to a jsp page, sending also some info that want to use there (using the GET method).
In my servlet i have the following code:

String link = new String("index.jsp?name="+metadata.getName()+"&title="+metadata.getTitle());

response.sendRedirect(response.encodeRedirectURL(link));

In the jsp, I get these parameters using

<%
request.getParameter("name");
request.getParameter("title");
%>

Everything works fine, except when the parameters do not contain only latin characters (in my case they can contain greek characters).
For example if name=ΕΡΕΥΝΑΣ i get name=¡¥.
How can i fix this encoding problem (setting it to UTF-8)?
Isn’t encodeRedirectURL() doing this job? Should I also use encodeURL() at some point? I tried the last one but problem still existed.

Thanks in advance 🙂

Answer 1

The HttpServletResponse#encodeRedirectURL() does not URL-encode the URL. It only appends the jsessionid attribute to the URL whenever there’s a session and the client has cookies disabled. Admittedly, it’s a confusing method name.

You need to encode the request parameters with help of URLEncoder#encode() yourself during composing the URL.

String charset = "UTF-8";
String link = String.format("index.jsp?name=%s&title=%s", 
    URLEncoder.encode(metadata.getName(), charset), 
    URLEncoder.encode(metadata.getTitle(), charset));

response.sendRedirect(response.encodeRedirectURL(link));

And create a filter which is mapped on /* and does basically the following in doFilter() method:

request.setCharacterEncoding("UTF-8");
chain.doFilter(request, response);

And add the following to top of your JSP:

<%@ page pageEncoding="UTF-8" %>

Finally you’ll be able to display them as follows:

<p>Name: ${param.name}</p>
<p>Title: ${param.title}</p>

See also:

• Unicode – How to get characters right?