CODEWITHSUNDEEP
javajavascripthtmljsp
user818700
user818700

Reputation:

Call Java Method From Within JavaScript Function?

I've been reading a bit but can't find a simple answer to this. Say I have a HTML page, and some Javascript embeded in that page. Plus I have a java.class in a package called somePackage.someSubPackage.*;

How would I be able to invoke a method in java.class from whithin a javascript function in my HTML page?

Upvotes: 0

Views: 2606

Answers (3)

Andrew Thompson
Andrew Thompson

Reputation: 168815

This works 'out of the box' for any browser with Java installed because the System class is part of the J2SE. 

<html>
<body>
<script type='text/javascript'>
document.write(java.lang.System.getProperty("java.version"));
</script>
</body>
</html>

To get it to work for custom classes (on the client side), it would usually require for those classes to be added to the class-path of a scriptable applet. Then use the JS/applet interface to invoke the methods & access the attributes.

Upvotes: 1

djna
djna

Reputation: 55897

Where is the Java going to run? It could be an Applet in the Browser or it could be running on a server somewhere.

JavaScript to Applet communication is possible, see, but most common these days is to use an AJAX call to a server.

You can wrap your Java as a callable service using several different techniques, I'd recommend using JAX/RS, it needs very little work. Your Java is then exposed as a callable URL that the JavaScript can invoke.

Hence you need to study two things:

  1. How to call an arbitrary service from JavaScript.
  2. How to run your Java in a server.

Two separate problems, but both pretty easy.

Upvotes: 4

Jigar Joshi
Jigar Joshi

Reputation: 240860

Use DWR

DWR will generate the JavaScript to allow web browsers to securely call into Java code almost as if it was running locally. It can marshal virtually any data including collections, POJOs, XML and binary data like images and PDF files. All that is required is a security policy that defines what is allowed.

Upvotes: 1

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