Passing Parameters to Scripts - Scripting in Java: Integrating with Groovy and JavaScript - page 23

Chapter 3

Passing Parameters
to Scripts

In this chapter, you will learn:

• Classes used in passing parameters from Java programs to scripts

• How to create and use

Bindings object to hold the parameters
How to define the scope of parameters •

• How to pass parameters to scripts using different objects and

scopes

• The advantages and disadvantages of different ways of passing

parameters

• How to write script's output to a file

Bindings, Scope, and Context
To understand the details of the parameter passing mechanism, three terms must be
understood clearly: bindings, scope, and context. These terms are confusing at first. This
chapter explains the parameter passing mechanism using the following steps:

• First, it defines these terms

• Second, it defines the relationship between these terms

• Third, it explains how to use them in Java programs

Bindings
A Bindings is a set of key-value pairs where all keys must be nonempty, non-null Strings.
In Java code, a Bindings is an instance of the Bindings interface. The SimpleBindings
class is an implementation of the Bindings interface. A script engine may provide its own
implementation of the Bindings interface.