mirror of
https://github.com/openjdk/jdk.git
synced 2025-09-17 17:44:40 +02:00
102 lines
4.6 KiB
HTML
102 lines
4.6 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">
|
|
<html>
|
|
<head>
|
|
<!--
|
|
Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
|
|
DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
|
|
|
|
This code is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU General Public License version 2 only, as
|
|
published by the Free Software Foundation. Oracle designates this
|
|
particular file as subject to the "Classpath" exception as provided
|
|
by Oracle in the LICENSE file that accompanied this code.
|
|
|
|
This code is distributed in the hope that it will be useful, but WITHOUT
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
|
|
version 2 for more details (a copy is included in the LICENSE file that
|
|
accompanied this code).
|
|
|
|
You should have received a copy of the GNU General Public License version
|
|
2 along with this work; if not, write to the Free Software Foundation,
|
|
Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
|
|
|
|
Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
|
|
or visit www.oracle.com if you need additional information or have any
|
|
questions.
|
|
-->
|
|
|
|
</head>
|
|
<body bgcolor="white">
|
|
<p>The scripting API consists of interfaces and classes that define
|
|
Java™ Scripting Engines and provides
|
|
a framework for their use in Java applications. This API is intended
|
|
for use by application programmers who wish to execute programs
|
|
written in scripting languages in their Java applications. The
|
|
scripting language programs are usually provided by the end-users of
|
|
the applications.
|
|
</p>
|
|
<p>The main areas of functionality of <code>javax.script</code>
|
|
package include
|
|
</p>
|
|
<ol>
|
|
<li><p><b>Script execution</b>: Scripts
|
|
are streams of characters used as sources for programs executed by
|
|
script engines. Script execution uses
|
|
{@link javax.script.ScriptEngine#eval eval} methods of
|
|
{@link javax.script.ScriptEngine ScriptEngine} and methods of the
|
|
{@link javax.script.Invocable Invocable} interface.
|
|
</p>
|
|
<li><p><b>Binding</b>: This facility
|
|
allows Java objects to be exposed to script programs as named
|
|
variables. {@link javax.script.Bindings Bindings} and
|
|
{@link javax.script.ScriptContext ScriptContext}
|
|
classes are used for this purpose.
|
|
</p>
|
|
<li><p><b>Compilation</b>: This
|
|
functionality allows the intermediate code generated by the
|
|
front-end of a script engine to be stored and executed repeatedly.
|
|
This benefits applications that execute the same script multiple
|
|
times. These applications can gain efficiency since the engines'
|
|
front-ends only need to execute once per script rather than once per
|
|
script execution. Note that this functionality is optional and
|
|
script engines may choose not to implement it. Callers need to check
|
|
for availability of the {@link javax.script.Compilable Compilable}
|
|
interface using an <I>instanceof</I> check.
|
|
</p>
|
|
<li><p><b>Invocation</b>: This
|
|
functionality allows the reuse of intermediate code generated by a
|
|
script engine's front-end. Whereas Compilation allows entire scripts
|
|
represented by intermediate code to be re-executed, Invocation
|
|
functionality allows individual procedures/methods in the scripts to
|
|
be re-executed. As in the case with compilation, not all script
|
|
engines are required to provide this facility. Caller has to check
|
|
for {@link javax.script.Invocable Invocable} availability.
|
|
</p>
|
|
<li><p><b>Script engine discovery and Metadata</b>: Applications
|
|
written to the Scripting API might have specific requirements on
|
|
script engines. Some may require a specific scripting language
|
|
and/or version while others may require a specific implementation
|
|
engine and/or version. Script engines are packaged in a specified
|
|
way so that engines can be discovered at runtime and queried for
|
|
attributes. The Engine discovery mechanism is based on the Service
|
|
discovery mechanism described in the <b>Jar File Specification</b>.
|
|
Script engine implementing classes are packaged in jar files that
|
|
include a text resource named
|
|
<b>META-INF/services/javax.script.ScriptEngineFactory</b>. This
|
|
resource must include a line for each
|
|
{@link javax.script.ScriptEngineFactory ScriptEngineFactory}
|
|
that is packaged in the jar file.
|
|
{@link javax.script.ScriptEngineManager ScriptEngineManager}
|
|
includes
|
|
{@link javax.script.ScriptEngineManager#getEngineFactories getEngineFactories} method to get all
|
|
{@link javax.script.ScriptEngineFactory ScriptEngineFactory} instances
|
|
discovered using this mechanism. <code>ScriptEngineFactory</code> has
|
|
methods to query attributes about script engine.
|
|
</p>
|
|
</ol>
|
|
|
|
@since 1.6
|
|
|
|
</body>
|
|
</html>
|