/*
* @(#)StringNormalizeFunction.java
*
* Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistribution of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
*
* 2. Redistribution in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MICROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
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package com.sun.xacml.cond;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeValue;
import com.sun.xacml.attr.StringAttribute;
/**
* A class that implements all the string conversion functions (string-normalize-space and
* string-normalize-to-lower-case). It takes string argument, normalizes that value, and returns the
* result. If the argument is indeterminate, an indeterminate result is returned.
*
* @since 1.0
* @author Steve Hanna
* @author Seth Proctor
*
* Adding generic type support by Christian Mueller (geotools)
*/
public class StringNormalizeFunction extends FunctionBase {
/**
* Standard identifier for the string-normalize-space function.
*/
public static final String NAME_STRING_NORMALIZE_SPACE = FUNCTION_NS + "string-normalize-space";
/**
* Standard identifier for the string-normalize-to-lower-case function.
*/
public static final String NAME_STRING_NORMALIZE_TO_LOWER_CASE = FUNCTION_NS
+ "string-normalize-to-lower-case";
// private identifiers for the supported functions
private static final int ID_STRING_NORMALIZE_SPACE = 0;
private static final int ID_STRING_NORMALIZE_TO_LOWER_CASE = 1;
/**
* Creates a new <code>StringNormalizeFunction</code> object.
*
* @param functionName
* the standard XACML name of the function to be handled by this object, including
* the full namespace
*
* @throws IllegalArgumentException
* if the function is unknown
*/
public StringNormalizeFunction(String functionName) {
super(functionName, getId(functionName), StringAttribute.identifier, false, 1,
StringAttribute.identifier, false);
}
/**
* Private helper that returns the internal identifier used for the given standard function.
*/
private static int getId(String functionName) {
if (functionName.equals(NAME_STRING_NORMALIZE_SPACE))
return ID_STRING_NORMALIZE_SPACE;
else if (functionName.equals(NAME_STRING_NORMALIZE_TO_LOWER_CASE))
return ID_STRING_NORMALIZE_TO_LOWER_CASE;
else
throw new IllegalArgumentException("unknown normalize function " + functionName);
}
/**
* Returns a <code>Set</code> containing all the function identifiers supported by this class.
*
* @return a <code>Set</code> of <code>String</code>s
*/
public static Set<String> getSupportedIdentifiers() {
Set<String> set = new HashSet<String>();
set.add(NAME_STRING_NORMALIZE_SPACE);
set.add(NAME_STRING_NORMALIZE_TO_LOWER_CASE);
return set;
}
/**
* Evaluate the function, using the specified parameters.
*
* @param inputs
* a <code>List</code> of <code>Evaluatable</code> objects representing the arguments
* passed to the function
* @param context
* an <code>EvaluationCtx</code> so that the <code>Evaluatable</code> objects can be
* evaluated
* @return an <code>EvaluationResult</code> representing the function's result
*/
public EvaluationResult evaluate(List<? extends Expression> inputs, EvaluationCtx context) {
// Evaluate the arguments
AttributeValue[] argValues = new AttributeValue[inputs.size()];
EvaluationResult result = evalArgs(inputs, context, argValues);
if (result != null)
return result;
// Now that we have real values, perform the numeric conversion
// operation in the manner appropriate for this function.
switch (getFunctionId()) {
case ID_STRING_NORMALIZE_SPACE: {
String str = ((StringAttribute) argValues[0]).getValue();
// Trim whitespace from start and end of string
int startIndex = 0;
int endIndex = str.length() - 1;
while ((startIndex <= endIndex) && Character.isWhitespace(str.charAt(startIndex)))
startIndex++;
while ((startIndex <= endIndex) && Character.isWhitespace(str.charAt(endIndex)))
endIndex--;
String strResult = str.substring(startIndex, endIndex + 1);
result = new EvaluationResult(new StringAttribute(strResult));
break;
}
case ID_STRING_NORMALIZE_TO_LOWER_CASE: {
String str = ((StringAttribute) argValues[0]).getValue();
// Convert string to lower case
String strResult = str.toLowerCase();
result = new EvaluationResult(new StringAttribute(strResult));
break;
}
}
return result;
}
}