Source code: com/sun/xacml/cond/StringNormalizeFunction.java
1
2 /*
3 * @(#)StringNormalizeFunction.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.StringAttribute;
43
44 import java.util.HashSet;
45 import java.util.List;
46 import java.util.Set;
47
48
49 /**
50 * A class that implements all the string conversion functions
51 * (string-normalize-space and string-normalize-to-lower-case).
52 * It takes string argument, normalizes that value, and returns
53 * the result. If the argument is indeterminate, an indeterminate
54 * result is returned.
55 *
56 * @since 1.0
57 * @author Steve Hanna
58 * @author Seth Proctor
59 */
60 public class StringNormalizeFunction extends FunctionBase
61 {
62
63 /**
64 * Standard identifier for the string-normalize-space function.
65 */
66 public static final String NAME_STRING_NORMALIZE_SPACE =
67 FUNCTION_NS + "string-normalize-space";
68
69 /**
70 * Standard identifier for the string-normalize-to-lower-case function.
71 */
72 public static final String NAME_STRING_NORMALIZE_TO_LOWER_CASE =
73 FUNCTION_NS + "string-normalize-to-lower-case";
74
75 // private identifiers for the supported functions
76 private static final int ID_STRING_NORMALIZE_SPACE = 0;
77 private static final int ID_STRING_NORMALIZE_TO_LOWER_CASE = 1;
78
79 /**
80 * Creates a new <code>StringNormalizeFunction</code> object.
81 *
82 * @param functionName the standard XACML name of the function to be
83 * handled by this object, including the full namespace
84 *
85 * @throws IllegalArgumentException if the function is unknown
86 */
87 public StringNormalizeFunction(String functionName) {
88 super(functionName, getId(functionName), StringAttribute.identifier,
89 false, 1, StringAttribute.identifier, false);
90 }
91
92 /**
93 * Private helper that returns the internal identifier used for the
94 * given standard function.
95 */
96 private static int getId(String functionName) {
97 if (functionName.equals(NAME_STRING_NORMALIZE_SPACE))
98 return ID_STRING_NORMALIZE_SPACE;
99 else if (functionName.equals(NAME_STRING_NORMALIZE_TO_LOWER_CASE))
100 return ID_STRING_NORMALIZE_TO_LOWER_CASE;
101 else
102 throw new IllegalArgumentException("unknown normalize function " +
103 functionName);
104 }
105
106 /**
107 * Returns a <code>Set</code> containing all the function identifiers
108 * supported by this class.
109 *
110 * @return a <code>Set</code> of <code>String</code>s
111 */
112 public static Set getSupportedIdentifiers() {
113 Set set = new HashSet();
114
115 set.add(NAME_STRING_NORMALIZE_SPACE);
116 set.add(NAME_STRING_NORMALIZE_TO_LOWER_CASE);
117
118 return set;
119 }
120
121 /**
122 * Evaluate the function, using the specified parameters.
123 *
124 * @param inputs a <code>List</code> of <code>Evaluatable</code>
125 * objects representing the arguments passed to the function
126 * @param context an <code>EvaluationCtx</code> so that the
127 * <code>Evaluatable</code> objects can be evaluated
128 * @return an <code>EvaluationResult</code> representing the
129 * function's result
130 */
131 public EvaluationResult evaluate(List inputs, EvaluationCtx context) {
132 // Evaluate the arguments
133 AttributeValue [] argValues = new AttributeValue[inputs.size()];
134 EvaluationResult result = evalArgs(inputs, context, argValues);
135 if (result != null)
136 return result;
137
138 // Now that we have real values, perform the numeric conversion
139 // operation in the manner appropriate for this function.
140 switch (getFunctionId()) {
141 case ID_STRING_NORMALIZE_SPACE: {
142 String str = ((StringAttribute) argValues[0]).getValue();
143
144 // Trim whitespace from start and end of string
145 int startIndex = 0;
146 int endIndex = str.length() - 1;
147 while ((startIndex <= endIndex) &&
148 Character.isWhitespace(str.charAt(startIndex)))
149 startIndex++;
150 while ((startIndex <= endIndex) &&
151 Character.isWhitespace(str.charAt(endIndex)))
152 endIndex--;
153 String strResult = str.substring(startIndex, endIndex+1);
154
155 result = new EvaluationResult(new StringAttribute(strResult));
156 break;
157 }
158 case ID_STRING_NORMALIZE_TO_LOWER_CASE: {
159 String str = ((StringAttribute) argValues[0]).getValue();
160
161 // Convert string to lower case
162 String strResult = str.toLowerCase();
163
164 result = new EvaluationResult(new StringAttribute(strResult));
165 break;
166 }
167 }
168
169 return result;
170 }
171 }