Win a copy of Spring in Action (5th edition) this week in the Spring forum!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
programming forums Java Mobile Certification Databases Caching Books Engineering Micro Controllers OS Languages Paradigms IDEs Build Tools Frameworks Application Servers Open Source This Site Careers Other all forums
this forum made possible by our volunteer staff, including ...
Marshals:
  • Campbell Ritchie
  • Bear Bibeault
  • Devaka Cooray
  • Liutauras Vilda
  • Jeanne Boyarsky
Sheriffs:
  • Knute Snortum
  • Junilu Lacar
  • paul wheaton
Saloon Keepers:
  • Ganesh Patekar
  • Frits Walraven
  • Tim Moores
  • Ron McLeod
  • Carey Brown
Bartenders:
  • Stephan van Hulst
  • salvin francis
  • Tim Holloway

Filters  RSS feed

 
Ranch Hand
Posts: 158
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
while i am working with FILTERS in java,

1) Is it compulsary to have a servlet when working with filter and

2) if i want to call a specific servlet using filters then how should we proceed.

please explain me with an example if possible along with deployment descriptor
 
Ranch Hand
Posts: 99
  • Mark post as helpful
  • send pies
  • Quote
  • Report post to moderator
No it's not mandatory to have a servlet in order to use a filter.

Say we have a filter:
<filter>
<filter-name>security</filter-name>
<filter-class>za.co.security.SecurityFilter</filter-class>
</filter>

<filter-mapping>
<filter-name>security</filter-name>
<url-pattern>/*</url-pattern>
</filter-mapping>

This will filter ALL requests received, irrespective of the resource requested. Images, pages, stylesheets, the works.

I'm not entirely sure what you ment by calling a servlet using a filter, but I suspect you either want to redirect to the servlet url, or request a servlet resource while processing a user request.

1) Redirecting:
public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException
{
response.sendRedirect("/myservletUrl.jsp");
return;
}

2) Requesting a servlet:
{
java.net.URL url = new java.net.URL("htpp://myserver/myServlet.go");
InputStream myStream = url.openStream();
//Code to read servlets' response from the myStream InputStream
}
 
It is sorta covered in the JavaRanch Style Guide.
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
Boost this thread!