/*
* @(#)AddFunction.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.
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* 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
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* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
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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.DoubleAttribute;
import com.sun.xacml.attr.IntegerAttribute;
/**
* A class that implements all the *-add functions. It takes two or more operands of the appropriate
* type and returns the sum of the operands. If any of the operands 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 AddFunction extends FunctionBase {
/**
* Standard identifier for the integer-add function.
*/
public static final String NAME_INTEGER_ADD = FUNCTION_NS + "integer-add";
/**
* Standard identifier for the double-add function.
*/
public static final String NAME_DOUBLE_ADD = FUNCTION_NS + "double-add";
// inernal identifiers for each of the supported functions
private static final int ID_INTEGER_ADD = 0;
private static final int ID_DOUBLE_ADD = 1;
/**
* Creates a new <code>AddFunction</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 AddFunction(String functionName) {
super(functionName, getId(functionName), getArgumentType(functionName), false, -1, 2,
getArgumentType(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_INTEGER_ADD))
return ID_INTEGER_ADD;
else if (functionName.equals(NAME_DOUBLE_ADD))
return ID_DOUBLE_ADD;
else
throw new IllegalArgumentException("unknown add function " + functionName);
}
/**
* 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_INTEGER_ADD))
return IntegerAttribute.identifier;
else
return DoubleAttribute.identifier;
}
/**
* 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_INTEGER_ADD);
set.add(NAME_DOUBLE_ADD);
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 add operation
switch (getFunctionId()) {
case ID_INTEGER_ADD: {
long sum = 0;
for (int index = 0; index < argValues.length; index++) {
long arg = ((IntegerAttribute) argValues[index]).getValue();
sum += arg;
}
result = new EvaluationResult(new IntegerAttribute(sum));
break;
}
case ID_DOUBLE_ADD: {
double sum = 0;
for (int index = 0; index < argValues.length; index++) {
double arg = ((DoubleAttribute) argValues[index]).getValue();
sum = sum + arg;
}
result = new EvaluationResult(new DoubleAttribute(sum));
break;
}
}
return result;
}
}