/*
* @(#)NumericConvertFunction.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
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
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*
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*/
package com.sun.xacml.cond;
import com.sun.xacml.EvaluationCtx;
import com.sun.xacml.attr.AttributeValue;
import com.sun.xacml.attr.DoubleAttribute;
import com.sun.xacml.attr.IntegerAttribute;
import java.util.HashSet;
import java.util.List;
import java.util.Set;
/**
* A class that implements all the numeric type conversion functions
* (double-to-integer and integer-to-double). It takes one argument
* of the appropriate type, converts that argument to the other type,
* and returns the result. If the argument is indeterminate, an
* indeterminate result is returned.
*
* @since 1.0
* @author Steve Hanna
* @author Seth Proctor
*/
public class NumericConvertFunction extends FunctionBase
{
/**
* Standard identifier for the double-to-integer function.
*/
public static final String NAME_DOUBLE_TO_INTEGER =
FUNCTION_NS + "double-to-integer";
/**
* Standard identifier for the integer-to-double function.
*/
public static final String NAME_INTEGER_TO_DOUBLE =
FUNCTION_NS + "integer-to-double";
// private identifiers for the supported functions
private static final int ID_DOUBLE_TO_INTEGER = 0;
private static final int ID_INTEGER_TO_DOUBLE = 1;
/**
* Creates a new <code>NumericConvertFunction</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 unknwon
*/
public NumericConvertFunction(String functionName) {
super(functionName, getId(functionName), getArgumentType(functionName),
false, 1, getReturnType(functionName), false);
}
/**
* Private helper that returns the internal identifier used for the
* given standard function.
*/
private static int getId(String functionName) {
if (functionName.equals(NAME_DOUBLE_TO_INTEGER)) {
return ID_DOUBLE_TO_INTEGER;
} else if (functionName.equals(NAME_INTEGER_TO_DOUBLE)) {
return ID_INTEGER_TO_DOUBLE;
} else {
throw new IllegalArgumentException("unknown convert 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_DOUBLE_TO_INTEGER);
set.add(NAME_INTEGER_TO_DOUBLE);
return set;
}
/**
* Private helper that returns the type used for the given standard
* function. Note that this doesn't check on the return value since the
* method always is called after getId, so we assume that the function
* is present.
*/
private static String getArgumentType(String functionName) {
if (functionName.equals(NAME_DOUBLE_TO_INTEGER)) {
return DoubleAttribute.identifier;
}
return IntegerAttribute.identifier;
}
/**
* Private helper that returns the return type for the given standard
* function. Note that this doesn't check on the return value since the
* method always is called after getId, so we assume that the function
* is present.
*/
private static String getReturnType(String functionName) {
if (functionName.equals(NAME_DOUBLE_TO_INTEGER)) {
return IntegerAttribute.identifier;
}
return DoubleAttribute.identifier;
}
/**
* 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<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.
if (getFunctionId() == ID_DOUBLE_TO_INTEGER) {
double arg0 = ((DoubleAttribute) argValues[0]).getValue();
long longValue = (long) arg0;
result = new EvaluationResult(new IntegerAttribute(longValue));
} else if (getFunctionId() == ID_INTEGER_TO_DOUBLE) {
long arg0 = ((IntegerAttribute) argValues[0]).getValue();
double doubleValue = arg0;
result = new EvaluationResult(new DoubleAttribute(doubleValue));
}
return result;
}
}