1/*
2 * Copyright (c) 2005, 2013, 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
18 * 2 along with this work; if not, write to the Free Software Foundation,
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
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package javax.script;
27
28/**
29 * The optional interface implemented by ScriptEngines whose methods allow the invocation of
30 * procedures in scripts that have previously been executed.
31 *
32 * @author  Mike Grogan
33 * @author  A. Sundararajan
34 * @since 1.6
35 */
36public interface Invocable  {
37    /**
38     * Calls a method on a script object compiled during a previous script execution,
39     * which is retained in the state of the <code>ScriptEngine</code>.
40     *
41     * @param name The name of the procedure to be called.
42     *
43     * @param thiz If the procedure is a member  of a class
44     * defined in the script and thiz is an instance of that class
45     * returned by a previous execution or invocation, the named method is
46     * called through that instance.
47     *
48     * @param args Arguments to pass to the procedure.  The rules for converting
49     * the arguments to scripting variables are implementation-specific.
50     *
51     * @return The value returned by the procedure.  The rules for converting the scripting
52     * variable returned by the script method to a Java Object are implementation-specific.
53     *
54     * @throws ScriptException if an error occurs during invocation of the method.
55     * @throws NoSuchMethodException if method with given name or matching argument types cannot be found.
56     * @throws NullPointerException if the method name is null.
57     * @throws IllegalArgumentException if the specified thiz is null or the specified Object is
58     * does not represent a scripting object.
59     */
60    public Object invokeMethod(Object thiz, String name, Object... args)
61        throws ScriptException, NoSuchMethodException;
62
63    /**
64     * Used to call top-level procedures and functions defined in scripts.
65     *
66     * @param name of the procedure or function to call
67     * @param args Arguments to pass to the procedure or function
68     * @return The value returned by the procedure or function
69     *
70     * @throws ScriptException if an error occurs during invocation of the method.
71     * @throws NoSuchMethodException if method with given name or matching argument types cannot be found.
72     * @throws NullPointerException if method name is null.
73     */
74     public Object invokeFunction(String name, Object... args)
75        throws ScriptException, NoSuchMethodException;
76
77
78     /**
79     * Returns an implementation of an interface using functions compiled in
80     * the interpreter. The methods of the interface
81     * may be implemented using the <code>invokeFunction</code> method.
82     *
83     * @param <T> the type of the interface to return
84     * @param clasz The <code>Class</code> object of the interface to return.
85     *
86     * @return An instance of requested interface - null if the requested interface is unavailable,
87     * i. e. if compiled functions in the <code>ScriptEngine</code> cannot be found matching
88     * the ones in the requested interface.
89     *
90     * @throws IllegalArgumentException if the specified <code>Class</code> object
91     * is null or is not an interface.
92     */
93    public <T> T getInterface(Class<T> clasz);
94
95    /**
96     * Returns an implementation of an interface using member functions of
97     * a scripting object compiled in the interpreter. The methods of the
98     * interface may be implemented using the <code>invokeMethod</code> method.
99     *
100     * @param <T> the type of the interface to return
101     * @param thiz The scripting object whose member functions are used to implement the methods of the interface.
102     * @param clasz The <code>Class</code> object of the interface to return.
103     *
104     * @return An instance of requested interface - null if the requested interface is unavailable,
105     * i. e. if compiled methods in the <code>ScriptEngine</code> cannot be found matching
106     * the ones in the requested interface.
107     *
108     * @throws IllegalArgumentException if the specified <code>Class</code> object
109     * is null or is not an interface, or if the specified Object is
110     * null or does not represent a scripting object.
111     */
112     public <T> T getInterface(Object thiz, Class<T> clasz);
113
114}
115