1) Introduction

Java Expression Language, also abbrevated as JEXL, is a simple java library which can be used for the implementation of dynamic scripting in Java Applications.

JEXL framework includes both API and Scripting language. Basically, JEXL engine(included as part of API) will executes the scirpts, written in JEXL Script.

JEXL scripting language is inspiried by Apache velocity and expression language defined in the JSP standard Tag library(JSTL v 1.1) and JSP version 2.0. JEXL supperts most of the constructs in shell-script or ECMAScript.

The API and the expression language uses the Java-beans naming patterns through introspection to expose property getters and setters. It also considers public class fields as properties and allows to invoke any accessible method

JEXl library is small and easy to implement .