Automatically printing on clients printer using servlets

Thanks for the response, I was pretty sure it couldn't be done, but I wanted to make sure. I'll look into the Applet route.

I haven't wrote Applets before, but isn't it true that IE5 comes with Java disabled by default? So if I write this Applet most of my clients couldn't use it without turning on Java on there browser?

jerkyboy at 2007-6-29 12:04:17 >

Hello

Applets cannot directly access printing services on the client's local machine. However Signed Applets ,with proper permissions , can access printing services.

In order to print Images, rtf docs, pdf docs directly from a page with just one button click, signed applet is the best solution from a Java Technology point of view. You may have to use printing APIs provided in java.awt.* package or java.awt.print.* package. However there is one wrinkle in using java.awt.print.*. Apparently this package is from Java 2 and IE may not fully support this package. So I would suggest in using java.awt.* package classes.

From a security purposes you may have to use both Netscape's Security APIs and Microsoft APIs to assert permissions for printing. For example you can assert permission as follows:

boolean cblnIsNetscape = System.getProperty("java.vendor").substring(0,8).equals("Netscape");

if( !cblnIsNetscape && Class.forName( "com.ms.security.PolicyEngine") != null )

{com.ms.security.PolicyEngine.assertPermission( com.ms.security.PermissionID.PRINTING );

}

if( cblnIsNetscape )netscape.security.PrivilegeManager.enablePrivilege("UniversalPrintJobAccess");

In order to communicate with the server, you may have to implement Applet-Servlet communication with a Applet receiving the image object or doc data in byte[] format that is serialized by a Servlet into the ioStream using ObjectOutputStream. You can design the architecture according to your requirements.

Once you get Image object or doc data, you have to render this onto a container like panel or textPane without actually displaying the container to the user. Ths is required because printing object gives you a java.awt.Graphics object on which the data needs to be renderred. So in anyway you have to render the data on a container. You can refer to java.awt.* apis docs for more information on printing using awt components or swing components.

One more issue regarding signed applets. Netscape accepts jar files for signed applets but IE does not recognize signed jar files. IE reads signed cabinet(cab)files. The files can be created using Microsofts Java SDK that can be downloaded from Microsoft site.

The cab file location should be specified as a param to the applet like

<param name="CABBASE" value="mydir/myapplet.cab">

or

<param name="CABINETS" value="mydir/firstapp.cab,mydir/secondapp.cab">

The following site contains detailed info regarding signing applets for both IE and Netscape:

http://www.suitable.com/Doc_CodeSigning.shtml

Swing provides some apis to render rtf documents. I think there are some apis that are available free that can render pdf files too.

Hope that gives some input to your query.

Kashabm

kashabm at 2007-6-29 12:04:17 >