Source code: com/sun/xacml/cond/ModFunction.java
1
2 /*
3 * @(#)ModFunction.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
41 import com.sun.xacml.attr.AttributeValue;
42 import com.sun.xacml.attr.IntegerAttribute;
43
44 import java.util.HashSet;
45 import java.util.List;
46 import java.util.Set;
47
48
49 /**
50 * A class that implements the integer-mod function. It takes two
51 * integer operands and returns the remainder. If either of the
52 * operands is indeterminate, an indeterminate result is returned.
53 *
54 * @since 1.0
55 * @author Steve Hanna
56 * @author Seth Proctor
57 */
58 public class ModFunction extends FunctionBase
59 {
60
61 /**
62 * Standard identifier for the integer-mod function.
63 */
64 public static final String NAME_INTEGER_MOD = FUNCTION_NS + "integer-mod";
65
66 /**
67 * Creates a new <code>ModFunction</code> object.
68 *
69 * @param functionName the standard XACML name of the function to be
70 * handled by this object, including the full namespace
71 *
72 * @throws IllegalArgumentException if the function is unknown
73 */
74 public ModFunction(String functionName) {
75 super(NAME_INTEGER_MOD, 0, IntegerAttribute.identifier, false,
76 2, IntegerAttribute.identifier, false);
77
78 if (! functionName.equals(NAME_INTEGER_MOD))
79 throw new IllegalArgumentException("unknown mod function: "
80 + functionName);
81 }
82
83 /**
84 * Returns a <code>Set</code> containing all the function identifiers
85 * supported by this class.
86 *
87 * @return a <code>Set</code> of <code>String</code>s
88 */
89 public static Set getSupportedIdentifiers() {
90 Set set = new HashSet();
91
92 set.add(NAME_INTEGER_MOD);
93
94 return set;
95 }
96
97 /**
98 * Evaluate the function, using the specified parameters.
99 *
100 * @param inputs a <code>List</code> of <code>Evaluatable</code>
101 * objects representing the arguments passed to the function
102 * @param context an <code>EvaluationCtx</code> so that the
103 * <code>Evaluatable</code> objects can be evaluated
104 * @return an <code>EvaluationResult</code> representing the
105 * function's result
106 */
107 public EvaluationResult evaluate(List inputs, EvaluationCtx context) {
108
109 // Evaluate the arguments
110 AttributeValue [] argValues = new AttributeValue[inputs.size()];
111 EvaluationResult result = evalArgs(inputs, context, argValues);
112 if (result != null)
113 return result;
114
115 // Now that we have real values, perform the mod operation
116 long arg0 = ((IntegerAttribute) argValues[0]).getValue();
117 long arg1 = ((IntegerAttribute) argValues[1]).getValue();
118
119 return new EvaluationResult(new IntegerAttribute(arg0 % arg1));
120 }
121 }