Setting ISO-8859-1 encoding for a single Tapestry 4 page in application that is otherwise totally UTF-8

Question

I have a Tapestry application that is serving its page as UTF-8. That is, server responses have header:

Content-type: text/html;charset=UTF-8

Now within this application there is a single page that should be served with ISO-8859-1 encoding. That is, server response should have this header:

Content-type: text/html;charset=ISO-8859-1

How to do this? I don't want to change default encoding for whole application.

Based on google searching I have tried following:

 @Meta({    "org.apache.tapestry.output-encoding=ISO-8859-1", 
    "org.apache.tapestry.response-encoding=ISO-8859-1", 
    "org.apache.tapestry.template-encoding=ISO-8859-1",
    "tapestry.response-encoding=ISO-8859-1"})
 abstract class MyPage extends BasePage {

    @Override
    protected String getOutputEncoding() {
        return "ISO-8859-1";
    }
 }

But neither setting those values with @Meta annotation or overriding getOutputEncoding method works.

I am using Tapestry 4.0.2.

EDIT: I ended up doing this with a Servlet filter with subclassed HttpServletResposeWrapper. The wrapper overrides setContentType() to force required encoding for the response.

Answer 1

Have you considered a Filter? Maybe not as elegant as something within Tapestry, but using a plain Filter, that registers the url mapping(s) of interest. One of its init parameters would be the encoding your after. Example:

public class EncodingFilter implements Filter {
private String encoding;
private FilterConfig filterConfig;

/**
* @see javax.servlet.Filter#init(javax.servlet.FilterConfig)
*/
public void init(FilterConfig fc) throws ServletException {
this.filterConfig = fc;
this.encoding = filterConfig.getInitParameter("encoding");
}

/**
* @see javax.servlet.Filter#doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)
*/
public void doFilter(ServletRequest req, ServletResponse resp,
FilterChain chain) throws IOException, ServletException {
req.setCharacterEncoding(encoding);
chain.doFilter(req, resp);
}

/**
* @see javax.servlet.Filter#destroy()
*/
public void destroy() {
}

}