Source code: com/sun/xacml/cond/FloorFunction.java
1
2 /*
3 * @(#)FloorFunction.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.DoubleAttribute;
43 import com.sun.xacml.attr.IntegerAttribute;
44
45 import java.util.HashSet;
46 import java.util.List;
47 import java.util.Set;
48
49
50 /**
51 * A class that implements the floor function. It takes one double
52 * operand, chooses the largest integer less than or equal to that
53 * value, and returns that integer (as a double). If the operand
54 * is indeterminate, an indeterminate result is returned.
55 *
56 * @since 1.0
57 * @author Steve Hanna
58 * @author Seth Proctor
59 */
60 public class FloorFunction extends FunctionBase
61 {
62
63 /**
64 * Standard identifier for the floor function.
65 */
66 public static final String NAME_FLOOR = FUNCTION_NS + "floor";
67
68 /**
69 * Creates a new <code>FloorFunction</code> object.
70 *
71 * @param functionName the standard XACML name of the function to be
72 * handled by this object, including the full namespace
73 *
74 * @throws IllegalArgumentException if the function is unknown
75 */
76 public FloorFunction(String functionName) {
77 super(NAME_FLOOR, 0, DoubleAttribute.identifier, false, 1,
78 DoubleAttribute.identifier, false);
79
80 if (! functionName.equals(NAME_FLOOR))
81 throw new IllegalArgumentException("unknown floor function: "
82 + functionName);
83 }
84
85 /**
86 * Returns a <code>Set</code> containing all the function identifiers
87 * supported by this class.
88 *
89 * @return a <code>Set</code> of <code>String</code>s
90 */
91 public static Set getSupportedIdentifiers() {
92 Set set = new HashSet();
93
94 set.add(NAME_FLOOR);
95
96 return set;
97 }
98
99 /**
100 * Evaluate the function, using the specified parameters.
101 *
102 * @param inputs a <code>List</code> of <code>Evaluatable</code>
103 * objects representing the arguments passed to the function
104 * @param context an <code>EvaluationCtx</code> so that the
105 * <code>Evaluatable</code> objects can be evaluated
106 * @return an <code>EvaluationResult</code> representing the
107 * function's result
108 */
109 public EvaluationResult evaluate(List inputs, EvaluationCtx context) {
110
111 // Evaluate the arguments
112 AttributeValue [] argValues = new AttributeValue[inputs.size()];
113 EvaluationResult result = evalArgs(inputs, context, argValues);
114 if (result != null)
115 return result;
116
117 // Now that we have real values, perform the floor operation
118 double arg = ((DoubleAttribute) argValues[0]).getValue();
119
120 return new EvaluationResult(new DoubleAttribute(Math.floor(arg)));
121 }
122 }