kylestev / jvm.js

A Java VM bytecode library written in ES6 for Node.js

jvm.js

A bytecode library for Java written in Node.js

This module is under active development and has not yet reached a stable release. This module will be following SemVer once it is ready for use by 3rd parties.

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Installation

$ npm install jvm

And you will be able to get started with using jvm.js. Take a look at the next section for some examples of how to get started.

Examples

jvm.js makes use of Promises instead of passing callbacks in functions. This allows your code to not fall victim to the node callback tree of doom. You'll see examples of it in the examples below.

If you're unfamiliar with Promises, or need a refresher, checkout Mozilla's excellent documentation here.

Loading a Jar's classes

The example below uses ES6 and shows how easy it is to parse a Jar file.

import { Jar } from 'jvm';

Jar.unpack('./test.jar')
  .then((jar) => {
    for (let [name, cls] of jar) {
      if (cls.name === 'client') {
        console.log('found client class!');
        console.log(JSON.stringify({
          name: cls.name,
          superName: cls.superName,
          methodCount: cls.methods.length,
          fieldCount: cls.fields.length
        }, null, 2));
      }
    }
  })
  .catch(console.error.bind(console));