Home / FAQ / Server-Side Development / JSP

Christopher Schultz

I've had occation to write code like this, too. I wrote a simple interface to get an InputStream for a file:

public interface ResourceResolver
{
   public InputStream getResource(String filename)
      throws IOException;
}

You can create one of these and pass it to your utility method, so it can be called-back:

public void someMethod(String filename, ResourceResolver rr)
{
   InputStream is = rr.getResource(filename);

   // .. use the input stream
}

It can be created on-the-fly from your servlet, too:

public void doGet(...)
{
   ResourceResolver rr = new ResourceResolver()
   {
      public InputStream getResource(String filename)
         throws IOException
      {
          return getServletContext().getResourceAsStream(filename);
      }
   };

   UtilClass.someMethod(filename, rr);
}

You could adapt this technique to just resolve the filename, too, if you want.

Hope that helps,

-chris