Spring 3 how to handle multilanguage URL with same content

Question

I want to fully internationalize my web page and have URLs translated to different languages. For example

• http://example.tld/en/page
• http://example.tld/de/pagina

all aforementioned pages should be handled by same controller and show same content (translated to desired language of course, this i know how to do - using message properties).

So my questions are:

1. How to achieve this functionality using @RequestMapping annotation?
2. Can I configure such aliases in properties or XML file and then "inject" them into controller? i.e.:

properties file:

alias.page=page:pagina

Controller

@RequestMapping("${alias.page}")
...

Or something like this.

Thanks for answers.

Answer 1

I've solved this issue by creating own implementation of servlet Filter

import java.io.IOException;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;

public class ExampleFilter implements Filter {

    @Override
    public void init(FilterConfig fc) throws ServletException {}

    @Override
    public void doFilter(ServletRequest request, ServletResponse response, 
                        FilterChain fc) throws IOException, ServletException {

        // Needed for getting URL from request
        final HttpServletRequest hsRequest = (HttpServletRequest) request;
        String url = hsRequest.getRequestURI().substring(
                        hsRequest.getContextPath().length()
                     );

        /* This is just simple example. Here you can connect to database
           or read properties or XML file with your configuration */
        if ("/de/pagina".equals(url) || "/en/page".equals(url)) {
            // change url and forward 
            RequestDispatcher dispatcher = request.getRequestDispatcher("/page");
            dispatcher.forward(request, response);
        } else {
            // Do nothing, just send request and response to other filters
            fc.doFilter(request, response);
        }
    }

    @Override
    public void destroy() {}
}

The controller method to handle request will then look like

@Controller
public class MultiLangController {

    @RequestMapping(value="/page", method = RequestMethod.GET)
    public String pageMethod() {        
        return ...;
    }    
}

Finally publish the new filter into web.xml

<filter>
    <filter-name>MyExampleFilter</filter-name>
    <filter-class>
        com.path.to.filter.ExampleFilter
    </filter-class>
</filter>
<filter-mapping>
    <filter-name>MyExampleFilter</filter-name>
    <url-pattern>/*</url-pattern>
</filter-mapping>

And that should do the trick. If you don't need such flexibility, maybe UrlRewriteFilter (analogue of .htaccess for Java) will be sufficient.