1 /*
2 * Copyright (c) 2005, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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24 */
25
26 /**
27
28 <p>The scripting API consists of interfaces and classes that define
29 Java™ Scripting Engines and provides
30 a framework for their use in Java applications. This API is intended
31 for use by application programmers who wish to execute programs
32 written in scripting languages in their Java applications. The
33 scripting language programs are usually provided by the end-users of
34 the applications.
35 </p>
36 <p>The main areas of functionality of <code>javax.script</code>
37 package include
38 </p>
39 <ol>
40 <li><p><b>Script execution</b>: Scripts
41 are streams of characters used as sources for programs executed by
42 script engines. Script execution uses
43 {@link javax.script.ScriptEngine#eval eval} methods of
44 {@link javax.script.ScriptEngine ScriptEngine} and methods of the
45 {@link javax.script.Invocable Invocable} interface.
46 </p>
47 <li><p><b>Binding</b>: This facility
48 allows Java objects to be exposed to script programs as named
49 variables. {@link javax.script.Bindings Bindings} and
50 {@link javax.script.ScriptContext ScriptContext}
51 classes are used for this purpose.
52 </p>
53 <li><p><b>Compilation</b>: This
54 functionality allows the intermediate code generated by the
55 front-end of a script engine to be stored and executed repeatedly.
56 This benefits applications that execute the same script multiple
57 times. These applications can gain efficiency since the engines'
58 front-ends only need to execute once per script rather than once per
59 script execution. Note that this functionality is optional and
60 script engines may choose not to implement it. Callers need to check
61 for availability of the {@link javax.script.Compilable Compilable}
62 interface using an <I>instanceof</I> check.
63 </p>
64 <li><p><b>Invocation</b>: This
65 functionality allows the reuse of intermediate code generated by a
66 script engine's front-end. Whereas Compilation allows entire scripts
67 represented by intermediate code to be re-executed, Invocation
68 functionality allows individual procedures/methods in the scripts to
69 be re-executed. As in the case with compilation, not all script
70 engines are required to provide this facility. Caller has to check
71 for {@link javax.script.Invocable Invocable} availability.
72 </p>
73 <li><p><b>Script engine discovery</b>: Applications
74 written to the Scripting API might have specific requirements on
75 script engines. Some may require a specific scripting language
76 and/or version while others may require a specific implementation
77 engine and/or version. Script engines are packaged in a specified
78 way so that engines can be discovered at runtime and queried for
79 attributes. The Engine discovery mechanism is based on the service-provider
80 loading facility described in the {@link java.util.ServiceLoader} class.
81 {@link javax.script.ScriptEngineManager ScriptEngineManager}
82 includes
83 {@link javax.script.ScriptEngineManager#getEngineFactories getEngineFactories} method to get all
84 {@link javax.script.ScriptEngineFactory ScriptEngineFactory} instances
85 discovered using this mechanism. <code>ScriptEngineFactory</code> has
86 methods to query attributes about script engine.
87 </p>
88 </ol>
89
90 @since 1.6
91 */
92
93 package javax.script;
94