/*
* @(#)EvaluationResult.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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* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
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*
* You acknowledge that this software is not designed or intended for use in
* the design, construction, operation or maintenance of any nuclear facility.
*/
package com.sun.xacml.cond;
import java.util.List;
import java.util.Vector;
import com.sun.xacml.attr.AttributeValue;
import com.sun.xacml.attr.BooleanAttribute;
import com.sun.xacml.ctx.Status;
/**
* This is used in cases where a normal result is some AttributeValue, but
* if an attribute couldn't be resolved (or some other problem occurred),
* then a Status object needs to be returned instead. This is used instead of
* throwing an exception for performance, but mainly because failure to resolve
* an attribute is not an error case for the code, merely for the evaluation,
* and represents normal operation. Separate exception types will be added
* later to represent errors in pdp operation.
*
* @since 1.0
* @author Seth Proctor
* @author Ludwig Seitz
*/
public class EvaluationResult
{
/**
* This indicates that the result was indeterminate.
*/
private boolean wasInd;
/**
* The attribute value returned by this evaluation.
*/
private AttributeValue value;
/**
* The status of this evaluation (i.e. ok, missing attribute,
* syntax error, processing error)
*/
private Status status;
/**
* Single instances of EvaluationResults with false and true
* BooleanAttributes in them. This avoids the need to create
* new objects when performing boolean operations, which we
* do a lot of.
*/
private static EvaluationResult falseBooleanResult;
private static EvaluationResult trueBooleanResult;
/**
* Constructor that creates an <code>EvaluationResult</code> containing
* a single <code>AttributeValue</code>
*
* @param value the attribute value
*/
public EvaluationResult(AttributeValue value) {
this.wasInd = false;
this.value = value;
this.status = null;
}
/**
* Constructor that creates an <code>EvaluationResult</code> of
* Indeterminate, including Status data.
*
* @param status the error information
*/
public EvaluationResult(Status status) {
this.wasInd = true;
this.value = null;
this.status = status;
}
/**
* Returns true if the result was indeterminate
*
* @return true if there was an error
*/
public boolean indeterminate() {
return this.wasInd;
}
/**
* Returns the attribute value, or null if there was an error
*
* @return the attribute value or null
*/
public AttributeValue getAttributeValue() {
return this.value;
}
/**
* Returns the status if there was an error, or null it no error occurred
*
* @return the status or null
*/
public Status getStatus() {
return this.status;
}
/**
* Returns an <code>EvaluationResult</code> that represents
* the boolean value provided.
*
* @param value a boolean representing the desired value
* @return an <code>EvaluationResult</code> representing the
* appropriate value
*/
public static EvaluationResult getInstance(boolean value) {
if (value) {
return getTrueInstance();
}
return getFalseInstance();
}
/**
* Returns an <code>EvaluationResult</code> that represents
* a false value.
*
* @return an <code>EvaluationResult</code> representing a
* false value
*/
public static EvaluationResult getFalseInstance() {
if (falseBooleanResult == null) {
falseBooleanResult =
new EvaluationResult(BooleanAttribute.getFalseInstance());
}
return falseBooleanResult;
}
/**
* Returns an <code>EvaluationResult</code> that represents
* a true value.
*
* @return an <code>EvaluationResult</code> representing a
* true value
*/
public static EvaluationResult getTrueInstance() {
if (trueBooleanResult == null) {
trueBooleanResult =
new EvaluationResult(BooleanAttribute.getTrueInstance());
}
return trueBooleanResult;
}
/**
* Creates a missing attribute evaluation result.
* @param message
* @return
*/
public static EvaluationResult createMissingAttributeInstance(String message) {
List<String> statusMsg = new Vector<String>();
statusMsg.add(Status.STATUS_MISSING_ATTRIBUTE);
return new EvaluationResult(new Status(statusMsg, message));
}
}