Servlet for serving static content

Question

I deploy a webapp on two different containers (Tomcat and Jetty), but their default servlets for serving the static content have a different way of handling the URL structur

Answer 1

I've had good results with FileServlet, as it supports pretty much all of HTTP (etags, chunking, etc.).

Answer 2

Judging from the example information above, I think this entire article is based on a bugged behavior in Tomcat 6.0.29 and earlier. See https://issues.apache.org/bugzilla/show_bug.cgi?id=50026. Upgrade to Tomcat 6.0.30 and the behavior between (Tomcat|Jetty) should merge.

Answer 3

There is no need for completely custom implementation of the default servlet in this case, you can use this simple servlet to wrap request to the container's implementation:

package com.example;

import java.io.*;

import javax.servlet.*;
import javax.servlet.http.*;

public class DefaultWrapperServlet extends HttpServlet
{   
    public void doGet(HttpServletRequest req, HttpServletResponse resp)
        throws ServletException, IOException
    {
        RequestDispatcher rd = getServletContext().getNamedDispatcher("default");

        HttpServletRequest wrapped = new HttpServletRequestWrapper(req) {
            public String getServletPath() { return ""; }
        };

        rd.forward(wrapped, resp);
    }
}

Answer 4

I had the same problem and I solved it by using the code of the 'default servlet' from the Tomcat codebase.

https://github.com/apache/tomcat/blob/master/java/org/apache/catalina/servlets/DefaultServlet.java

The DefaultServlet is the servlet that serves the static resources (jpg,html,css,gif etc) in Tomcat.

This servlet is very efficient and has some the properties you defined above.

I think that this source code, is a good way to start and remove the functionality or depedencies you don't need.

• References to the org.apache.naming.resources package can be removed or replaced with java.io.File code.
• References to the org.apache.catalina.util package are propably only utility methods/classes that can be duplicated in your source code.
• References to the org.apache.catalina.Globals class can be inlined or removed.

Answer 5

See StaticFile in JSOS: http://www.servletsuite.com/servlets/staticfile.htm

Answer 6

I did this by extending the tomcat DefaultServlet (src) and overriding the getRelativePath() method.

package com.example;

import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import org.apache.catalina.servlets.DefaultServlet;

public class StaticServlet extends DefaultServlet
{
   protected String pathPrefix = "/static";

   public void init(ServletConfig config) throws ServletException
   {
      super.init(config);

      if (config.getInitParameter("pathPrefix") != null)
      {
         pathPrefix = config.getInitParameter("pathPrefix");
      }
   }

   protected String getRelativePath(HttpServletRequest req)
   {
      return pathPrefix + super.getRelativePath(req);
   }
}

... And here are my servlet mappings

<servlet>
    <servlet-name>StaticServlet</servlet-name>
    <servlet-class>com.example.StaticServlet</servlet-class>
    <init-param>
        <param-name>pathPrefix</param-name>
        <param-value>/static</param-value>
    </init-param>       
</servlet>

<servlet-mapping>
    <servlet-name>StaticServlet</servlet-name>
    <url-pattern>/static/*</url-pattern>
</servlet-mapping>