Source code: com/sun/xacml/cond/Evaluatable.java
1
2 /*
3 * @(#)Evaluatable.java
4 *
5 * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions are met:
9 *
10 * 1. Redistribution of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 *
13 * 2. Redistribution in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
16 *
17 * Neither the name of Sun Microsystems, Inc. or the names of contributors may
18 * be used to endorse or promote products derived from this software without
19 * specific prior written permission.
20 *
21 * This software is provided "AS IS," without a warranty of any kind. ALL
22 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
23 * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
24 * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
25 * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
26 * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
27 * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
28 * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
29 * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
30 * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
31 * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
32 *
33 * You acknowledge that this software is not designed or intended for use in
34 * the design, construction, operation or maintenance of any nuclear facility.
35 */
36
37 package com.sun.xacml.cond;
38
39 import com.sun.xacml.EvaluationCtx;
40 import com.sun.xacml.Indenter;
41
42 import com.sun.xacml.attr.AttributeValue;
43
44 import java.io.OutputStream;
45
46 import java.net.URI;
47
48 import java.util.List;
49
50
51 /**
52 * Generic interface that is implemented by all objects that can appear in
53 * an ApplyType. This lets the evaluation code of <code>Apply</code> and
54 * functions iterate through their members and evaluate them, working only
55 * on the returned values or errors.
56 *
57 * @since 1.0
58 * @author Seth Proctor
59 */
60 public interface Evaluatable
61 {
62
63 /**
64 * Evaluates the object using the given context, and either returns an
65 * error or a resulting value.
66 *
67 * @param context the representation of the request
68 *
69 * @return the result of evaluation
70 */
71 public EvaluationResult evaluate(EvaluationCtx context);
72
73 /**
74 * Get the type of this object. This may be the data type of an
75 * <code>Attribute</code> or the return type of an
76 * <code>AttributeDesignator</code>, etc.
77 *
78 * @return the type of data represented by this object
79 */
80 public URI getType();
81
82 /**
83 * Tells whether evaluation will return a bag or a single value.
84 *
85 * @return true if evaluation will return a bag, false otherwise
86 */
87 public boolean evaluatesToBag();
88
89 /**
90 * Returns all children, in order, of this element in the Condition
91 * tree, or en empty set if this element has no children. In XACML 1.x,
92 * only the ApplyType ever has children.
93 *
94 * @return a <code>List</code> of <code>Evaluatable</code>s
95 */
96 public List getChildren();
97
98 /**
99 * Encodes this <code>Evaluatable</code> into its XML representation and
100 * writes this encoding to the given <code>OutputStream</code> with no
101 * indentation.
102 *
103 * @param output a stream into which the XML-encoded data is written
104 */
105 public void encode(OutputStream output);
106
107 /**
108 * Encodes this <code>Evaluatable</code> into its XML representation and
109 * writes this encoding to the given <code>OutputStream</code> with
110 * indentation.
111 *
112 * @param output a stream into which the XML-encoded data is written
113 * @param indenter an object that creates indentation strings
114 */
115 public void encode(OutputStream output, Indenter indenter);
116
117 }