Java Pocket Guide

Chapter 16. The Java Scripting API

The Java Scripting API, introduced in Java SE 6, provides support that allows Java applications and scripting languages to interact through a standard interface. This API is detailed in the JSR 223, “Scripting for the Java Platform” and is contained in the javax.script package.

Scripting Languages

Several scripting languages have script engine implementations available that conform to JSR 223. See the “Scripting Languages” section in Chapter 17 for a subset of these supported languages.

Script Engine Implementations

The interface ScriptEngine provides the fundamental methods for the API. The class ScriptEngineManager works in conjunction with this interface and provides a means to establish the desired scripting engines to be utilized.

Embedding Scripts into Java

The scripting API includes the ability to embed scripts and/or scripting components into Java applications.

The following example shows two ways to embed scripting components into a Java application: (1) the scripting engine’s eval method reads in the scripting language syntax directly, and (2) the scripting engine’s eval method reads the syntax in from a file.

	import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import java.io.FileReader; public class HelloWorld { public static void main(String[] args) throws Exception { ScriptEngineManager m = new ScriptEngineManager( ); // Sets up Rhino JavaScript Engine. ScriptEngine e = m.getEngineByExtension("js"); // Rhino JavaScript ...