An easy way to expose a resource for download

Write a seam component that returns a resource object:

@Name("foo")
...
   public Resource getFile() {
      return new Resource() {
         public Object getContentType() {
            return "application/pdf";
         }

         public byte[] getContent() throws IOException {
            // Load data
         }

         public String getFileName() {
           return "file.pdf";
         }
     
         public Disposition getDisposition() {
            return Disposition.ATTACHMENT;
         }
      };
   }
   ...

Wire it using pages.xml

...
<page view-id="/file.pdf.xhtml" action="#{foo.file.render}" ></page>
...

And access it from the browser http://localhost:8080/myApp/file.pdf.jsf.

Here is the code for Resource

import java.io.IOException;
import javax.faces.context.FacesContext;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import org.jboss.seam.Component;

public abstract class Resource {
     
   public void render() throws IOException {
      FacesContext facesContext =  (FacesContext) Component.getInstance("facesContext");
      if (!facesContext.getResponseComplete()) {
         HttpServletResponse response = (HttpServletResponse) facesContext.getExternalContext().getResponse();
         response.setContentType(getContentType().toString());
         response.setContentLength(getContentSize());
         if (Disposition.ATTACHMENT.equals(getDisposition())) {
            response.setHeader("Content-disposition", "attachment; filename=" + getFileName());
         }
         ServletOutputStream out = response.getOutputStream();
         out.write(getContent());
         out.flush();
         facesContext.responseComplete();
      }
   }
     
   public enum Disposition {
      INLINE, ATTACHMENT;
   }

   public abstract Object getContentType();

   public abstract byte[] getContent() throws IOException;
     
   public int getContentSize() throws IOException {
      return getContent().length;
   }
     
   public String getFileName() {
      return "";
   }
     
   public Disposition getDisposition() {
      return Disposition.INLINE;
   }

}

• Note that this doesn't work on portals / portlets