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Janino 2.6.1

Publisher's description

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Antivirus report

"Compiles and executes Java on-the-fly."

Published by Arno Unkrig on 24 Jun 2010

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Size:
0.94 MB
License:
Freeware
OS:
Windows, Unix, Linux, Mac OS
Publisher:
Arno Unkrig
Updated:
24 Jun 2010
Downloads:
389 (0 last week)

Janino is a compiler that reads a Java expression, block, or source file, and generates Java bytecode that is loaded and executed directly. It is not intended to be a development tool, but an embedded compiler for run-time compilation purposes, such as expression evaluators or "server pages" engines like JSP.

Properties

The major design goal was to keep the compiler small and simple, while partially sacrificing completeness. I don't like the idea of carrying around huge libraries for simple applications. See Parser for the list of implemented and missing language features.

When do you need an efficient expression evaluator?

Say you build an e-commerce system, which computes the shipping cost for the items that the user put into his/her shopping cart. Because you don't know the merchant's shipping cost model at implementation time, you could implement a set of shipping cost models that come to mind (flat charge, by weight, by number of items, ...) and select one of those at run-time.

In practice, you will most certainly find that the shipping cost models you implemented will rarely match what the merchant wants, so you must add custom models, which are merchant-specific. If the merchant's model changes later, you must change your code, re-compile and re-distribute your software.

Because this is so unflexible, the shipping cost expression should be specified at run-time, not at compile-time. This implies that the expression must be scanned, parsed and evaluated at run-time, which is why you need an expression evaluator.

A simple expression evaluator would parse an expression and create a "syntax tree". The expression "a + b * c", for example, would compile into a "Sum" object who's first operand is parameter "a" and who's second operand is a "Product" object who's operands are parameters "b" and "c". Such a syntax tree can evaluated relatively quickly. However, the run-time performance is about a factor of 100 worse than that of native Java code.

Requirements: JDK 1.3.1 or above

What's new in this version: Updated the overview page.

Download Janino 2.6.1 (0.94 MB)

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Antivirus information

Download3K has downloaded and tested Janino on 28 Mar 2012 with some of Today's best antivirus engines and you can find below, for your convenience, the scan results:

Bitdefender:
Clean
NOD 32:
Clean
Avira:
Clean
Kaspersky:
Clean