Java Applet的嵌套罐

Question

First of all, I have gone through all the questions here regarding the inclusion of jar files for an applet. But even then, I have this 'Huge' Problem.

I am developing an application with java and the Apache-Tika Library (with 4 jars, totaling the size of 40 mbs). The application needs to count the number of words in an uploaded document (doc, docx, odf, pdf and a bunch of other). The applet runs pretty well from Netbeans 6.5 or Eclipse IDE which I am using side by side for the development. But when I try to Deploy it to a browser, there's a problem.

Problem

The initial page loads pretty good. But as I give the path of the document and Click Ok (or Count), I get loads of error messages. Those are all " Class Not Found Exceptions " related to the external Apache-Tika Library. I think I have done all the inclusion of the library correctly as other wise it wouldn't run in the applet viewer.

As for the HTML, I have created a jar of the entire Word-Counter Application, along with the library(4 Apache-Tika Jars) and all other necessary files, and included the jar in the tag accordingly. Do I need to mention anything on the HTML file about the nested jar library, is there a limitation regarding a nested jar? Any Kind of help would be Highly Appreciated. Thank You learned Folks in advance.

Answer 1

It sounds like you may be approaching this the wrong way. You really shouldn't be doing any document analysis from a browser Applet. Instead upload the document to a server and analyze it there. Requiring users to download 40MBs of jars is probably unacceptable as an end solution to anyone who will use the application you are creating.

Answer 2

"Class Not Found Exceptions" related to the external Apache-Tika Library.

Multiple Jars can be listed in the archive attribute of the applet element. See W3C on the archive attribute ..

This attribute specifies a comma-separated list of URIs for archives containing classes and other resources that will be "preloaded".

Answer 3

Why not just include all the classes from all the dependency jars inside your applet jar?

Tika includes a single jar that does that very thing - tika-app.jar . You can run the tika-app without needing any extra jars or dependencies, it includes everything that's required.

If you look at the tika-app pom, you'll see the appropriate maven magic to have such a jar built. Otherwise, to do it by hand, simply unpack all your jars into a single directory, then re-jar that up again.