Modify request URI in spring mvc - spring

Question

I have a spring mvc based application. I want to modify the request URI before it reaches controller. For example, RequestMapping for controller is "abc/xyz" but the request coming is "abc/1/xyz". I want to modify incoming request to map it to controller.
Solution1: Implement interceptor and modify incoming request URI. But the problem here is that as there is no controller matching the URI pattern "abc/1/xyz", it does not even goes to interceptor.(I might be missing something to enable it if its there)
Get around for it could be to have both of URI as request mapping for controller.
What other solutions could be there? Is there a way to handle this request even before it comes to spring. As in handle it at filter in web.xml, i am just making it up.

Answer 1

You could write a servlet Filter which wraps the HttpServletRequest and returns a different value for the method getRequestURI. Something like that:
public class RequestURIOverriderServletFilter implements Filter {
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {
chain.doFilter(new HttpServletRequestWrapper((HttpServletRequest) request) {
#Override
public String getRequestURI() {
// return what you want
}
}, response);
}
// ...
}
The servlet filter configuration must be added into the web.xml.
But sincerly, there is probably other way to solve your problems and you should not do this unless you have very good reasons.

Answer 2

in order to achieve this you should replace every place that affected when you calling uri.
the place that not mentioned is INCLUDE_SERVLET_PATH_ATTRIBUTE which is internally is accessed when going deeper.
public class AuthFilter implements Filter {
private final Logger logger = LoggerFactory.getLogger(AuthFilter.class);
private final String API_PREFIX = "/api";
#Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws ServletException, IOException {
HttpServletRequest httpRequest = (HttpServletRequest) request;
String requestURI = httpRequest.getRequestURI();
if (requestURI.startsWith(API_PREFIX)) {
String redirectURI = requestURI.substring(API_PREFIX.length());
StringBuffer redirectURL = new StringBuffer(((HttpServletRequest) request).getRequestURL().toString().replaceFirst(API_PREFIX, ""));
filterChain.doFilter(new HttpServletRequestWrapper((HttpServletRequest) request) {
#Override
public String getRequestURI() {
return redirectURI;
}
#Override
public StringBuffer getRequestURL() {
return redirectURL;
}
#Override
public Object getAttribute(String name) {
if(WebUtils.INCLUDE_SERVLET_PATH_ATTRIBUTE.equals(name))
return redirectURI;
return super.getAttribute(name);
}
}, response);
} else {
filterChain.doFilter(request, response);
}
}
}

Answer 3

You can use a URL Re-Write which are specifically meant for this purpose i.e. transform one request URI to another URI based on some regex.