修改Filter中URI的PathParam

Question

我需要修改 URI 路径变量。即每当我收到请求 "/api/stories/27/comments/32"，应该转换成"/api/stories/27/comments/323322X"

我已使用过滤器通过以下指定方法修改请求 URI：

@Component
public class HashIDFilter implements Filter {
    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
            throws IOException, ServletException {

        HttpServletRequest request = (HttpServletRequest) req;
        HttpServletResponse response = (HttpServletResponse) res;
        if (request.getRequestURL().toString().contains("/comments/")) {
            HttpServletRequestWrapper requestWrapper = new HttpServletRequestWrapper(request) {
                @Override
                public String getRequestURI() {
                    System.out.println("orig url:" + request.getRequestURL().toString());
                    String arr[] = request.getRequestURL().toString().split("/comments/");
                    String url = arr[0] + "/comments/" + "3442424/";// HashIdSimple.decode(arr[1]);
                    System.out.println("url:" + url);
                    return url;
                }
            };
request.getRequestDispatcher(requestWrapper.getRequestURI()).forward(request, response);
        } else {
            System.out.println("req");
            chain.doFilter(req, res);
        }
    }
}

报以下指定错误：

{
    "timestamp": "2019-10-26T14:32:19.932+0000",
    "status": 404,
    "error": "Not Found",
    "message": "No message available",
    "path": "/api/stories/27/comments/32"
}

我试过用

代替 RequestDispatcher

chain.doFilter(requestWrapper, response); 

仍然没有运气，因为它仅调用值为 32 的 API，即仅以前的值。请指导我解决此问题。

期望传入的请求 URI 应该在新的 URI 请求中得到修改，并且应该调用相应的 API。

Answer 1

通过删除 HttpServletRequestWrapper 来更新代码：

    @Component
    public class HashIDFilter implements Filter {
        @Override
        public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain)
                throws IOException, ServletException {

            HttpServletRequest request = (HttpServletRequest) req;
            HttpServletResponse response = (HttpServletResponse) res;
            if (request.getRequestURL().toString().contains("/comments/")) {  
               String arr[] = request.getRequestURL().toString().split("/comments/");
               String url = arr[0] + "/comments/" + "3442424/";
               request.getRequestDispatcher(url).forward(request, response);
            } else {
                chain.doFilter(req, res);
            }
        }
    }

在web.xml 中添加过滤器：

<?xml version="1.0" encoding="UTF-8"?>
<web-app id="WebApp_ID" version="2.4" 
         xmlns="http://java.sun.com/xml/ns/j2ee"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://java.sun.com/xml/ns/j2ee 
         http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd">

    <filter>
        <filter-name>hashIdFilter</filter-name>
        <filter-class>package.HashIDFilter</filter-class>
    </filter>
    <filter-mapping>
           <filter-name>hashIdFilter</filter-name>
           <url-pattern>/*</url-pattern>
    </filter-mapping>
</web-app>

请参阅这个受欢迎的SO Question 以供参考。