problem running the download JAR application

[Niranjan Deshpande]

hi all. I tried out the download jar file application from HFSJ book chapter 4. Here is my code -

web.xml

 <?xml version="1.0" encoding="ISO-8859-1"?>
 
<!DOCTYPE web-app
   PUBLIC "-//Sun Microsystems, Inc.//DTD Web Application 2.3//EN"
   "http://java.sun.com/dtd/web-app_2_3.dtd">
 
<web-app>
 
<servlet>
      <servlet-name>read a jar file</servlet-name>
      <servlet-class>com.example.web.CodeReturn</servlet-class>
 </servlet>
<servlet-mapping>
<servlet-name>read a jar file</servlet-name>
<url-pattern>/readfile.do</url-pattern>
</servlet-mapping>
<mime-mapping>
      <extension>jar</extension>
      <mime-type>application/jar</mime-type>
</mime-mapping>
</web-app>   

CodeReturn.java

  package com.example.web;
 
import javax.servlet.*;
import javax.servlet.http.*;
import java.io.*;
 
public class CodeReturn extends HttpServlet
{

public void doGet(HttpServletRequest request,
                  HttpServletResponse response)
    throws IOException,ServletException 
    {
response.setContentType("application/jar");
InputStream is = getServletContext().getResourceAsStream("/catalina.jar");
int read = 0;
byte[] bytes = new byte[1024];

OutputStream os = response.getOutputStream();
while( (read = is.read(bytes)) != -1) {
os.write(bytes,0,read);
}
    }
    public void doPost(HttpServletRequest request,
                  HttpServletResponse response)
    throws IOException,ServletException 
{
    doGet(request, response);
}


}  

the url that i am using to run the application is
http://localhost:8080/codeReturn/readfile.do
After this i am getting a download dialog box that asks me whether i want to download a "readfile.do" file, instead of the catalina.jar file as said in the CodeReturn.java source code.

The file gets downloaded by the name readfile.do, but its actually a catalina.jar file, because when i edit it , i can see the catalina specific
garbage characters. But the point is why is it getting saved as a readfile.do and not as a catalina.jar ?

I am into the second reading of the book, and i must execute this code as i was unable to execute it during the first reading. Also, in web.xml i have added the mime tags ( not mentioned in the book ), but still the app doesnt work !

Please help me
thanks in advance !