The default error page for java webapp can be set via web.xml

  ...
  
    /error
  

Several error pages can be defined with each assigned to specific error code

  
    404
    /notFoundError
  
  
    403
    /forbiddenError
  

If using Spring MVC, the error message and status code can be obtained on the handler using following request attributes:

("/error")
public String error(HttpServletRequest req) {
  Object message = req.getAttribute("javax.servlet.error.message");
  Object statusCode = req.getAttribute("javax.servlet.error.status_code");
  Object requestURI = req.getAttribute("javax.servlet.error.request_uri");
  // ...
}