Servlet response.sendRedirect encoding problems

Question

So I'm redirecting my user using GET in a naive way:

response.sendRedirect("/path/index.jsp?type="+ e.getType() 
   +"&message="+ e.getMessage());

And this was working fine until I had to send messages, as actual text to be shown to users. The problem is if the message has non-ASCII characters in it. My .jsp files are encoded in UTF-8:

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>

So all non-ASCII characters in 'message' gets garbled. I don't want to set my JVM default encoding to UTF-8, so how do I solve this? I tried to use

response.setCharacterEncoding("UTF-8");

on the Servlet before redirecting, but it doesn't work. when I try to execute:

out.print(request.getCharacterEncoding());

on my .jsp file it prints 'null'.

BalusC BalusC · Accepted Answer · 2012-11-08T13:38:30

The sendRedirect() method doesn't encode the query string for you. You've to do it yourself.

response.sendRedirect("/path/index.jsp?type=" + URLEncoder.encode(e.getType(), "UTF-8")
    + "&message=" + URLEncoder.encode(e.getMessage(), "UTF-8"));

You might want to refactor the boilerplate to an utility method taking a Map or so.

Note that I assume that the server is configured to decode the GET request URI using UTF-8 as well. You didn't tell which one you're using, but in case of for example Tomcat it's a matter of adding URIEncoding="UTF-8" attribute to the <Context> element.

Unrelated to the concrete problem, the language="java" is the default already, just omit it. The contentType="text/html; charset=UTF-8" is also the default already when using JSP with pageEncoding="UTF-8", just omit it. All you really need is <%@ page pageEncoding="UTF-8"%>. Note that this does effectively the same as response.setCharacterEncoding("UTF-8"), so that explains why it didn't have effect. The request.getCharacterEncoding() only concerns the POST request body, not the GET request URI, so it is irrelevant in case of GET requests.

Servlet response.sendRedirect encoding problems

2 Answers

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