/**
* Copyright (c) 2011, SOCIETIES Consortium (WATERFORD INSTITUTE OF TECHNOLOGY (TSSG), HERIOT-WATT UNIVERSITY (HWU), SOLUTA.NET
* (SN), GERMAN AEROSPACE CENTRE (Deutsches Zentrum fuer Luft- und Raumfahrt e.V.) (DLR), Zavod za varnostne tehnologije
* informacijske družbe in elektronsko poslovanje (SETCCE), INSTITUTE OF COMMUNICATION AND COMPUTER SYSTEMS (ICCS), LAKE
* COMMUNICATIONS (LAKE), INTEL PERFORMANCE LEARNING SOLUTIONS LTD (INTEL), PORTUGAL TELECOM INOVAÇÃO, SA (PTIN), IBM Corp.,
* INSTITUT TELECOM (ITSUD), AMITEC DIACHYTI EFYIA PLIROFORIKI KAI EPIKINONIES ETERIA PERIORISMENIS EFTHINIS (AMITEC), TELECOM
* ITALIA S.p.a.(TI), TRIALOG (TRIALOG), Stiftelsen SINTEF (SINTEF), NEC EUROPE LTD (NEC))
* 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. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions 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.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
* BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
* SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.societies.api.privacytrust.trust.model;
import java.io.Serializable;
import java.util.Date;
import org.societies.api.privacytrust.trust.evidence.TrustEvidenceType;
/**
* This class is used to represent direct and indirect trust evidence with
* regards to CSSs, CISs or services. Trust evidence data are the basis for
* evaluating the {@link TrustValueType#DIRECT direct} and
* {@link TrustValueType#INDIRECT indirect} trust in these entities.
* <p>
* More specifically, each piece of trust evidence is associated with a
* <i>subject</i> and an <i>object</i>, as well as, the
* {@link TrustEvidenceType type} characterising that particular piece of
* evidence. Depending on the type, supplementary <i>information</i> can also
* be specified. Some examples of trust evidence follow:
* <table>
* <tr><th>subject</th> <th>object</th> <th>type</th> <th>info</th></tr>
* <tr><td>CSS</td> <td>CSS/CIS/Service</td> <td>{@link TrustEvidenceType#RATED RATED}</td><td><code>Double</code> [0,1]</td></tr>
* <tr><td>CSS</td> <td>CSS</td> <td>{@link TrustEvidenceType#FRIENDED_USER FRIENDED_USER}</td> <td><code>null</code></td></tr>
* <tr><td>CSS</td> <td>CSS</td> <td>{@link TrustEvidenceType#UNFRIENDED_USER UNFRIENDED_USER}</td> <td><code>null</code></td></tr>
* <tr><td>CSS</td> <td>CIS</td> <td>{@link TrustEvidenceType#JOINED_COMMUNITY JOINED_COMMUNITY}</td> <td><code>null</code></td></tr>
* <tr><td>CSS</td> <td>CIS</td> <td>{@link TrustEvidenceType#LEFT_COMMUNITY LEFT_COMMUNITY}</td> <td><code>null</code></td></tr>
* <tr><td>CSS</td> <td>Service</td> <td>{@link TrustEvidenceType#USED_SERVICE USED_SERVICE}</td> <td><code>Double</code> [0,1] (optional)</td></tr>
* </table>
* <p>
* Direct trust evidence are collected locally with respect to the CSS owner,
* while indirect trust evidence originate from other sources. Thus, indirect
* trust evidence are also accompanied with the <i>source</i> from which they
* originate.
*
* @author <a href="mailto:nicolas.liampotis@cn.ntua.gr">Nicolas Liampotis</a> (ICCS)
* @since 1.1
*/
public class TrustEvidence implements Serializable, Comparable<TrustEvidence> {
private static final long serialVersionUID = 3081731373916156074L;
/** The subject this piece of trust evidence refers to. */
private final TrustedEntityId subjectId;
/** The object this piece of trust evidence refers to. */
private final TrustedEntityId objectId;
/** The type of this piece of trust evidence. */
private final TrustEvidenceType type;
/** The date and time when this piece of trust evidence was collected. */
private final Date timestamp;
/** Supplementary information if applicable */
private final Serializable info;
/** The source of this piece of (indirect) trust evidence. */
private final TrustedEntityId sourceId;
/**
* Constructs a <code>TrustEvidence</code> object with the specified
* attributes.
*
* @param subjectId
* (required) the {@link TrustedEntityId} of the subject
* this piece of trust evidence refers to.
* @param objectId
* (required) the {@link TrustedEntityId} of the object
* this piece of trust evidence refers to.
* @param type
* (required) the {@link TrustEvidenceType type} of this piece
* of trust evidence.
* @param timestamp
* (required) the date and time when this piece of trust
* evidence was collected.
* @param info
* (optional) supplementary information if applicable; otherwise
* <code>null</code>.
* @param sourceId
* (optional) if specified, identifies the source of this piece
* of indirect trust evidence; otherwise <code>null</code> to
* denote a piece of direct trust evidence.
* @throws NullPointerException if any of the required parameters is
* <code>null</code>
* @throws IllegalArgumentException if the specified info is an out of
* range Double, i.e. not within [0,1].
*/
public TrustEvidence(final TrustedEntityId subjectId,
final TrustedEntityId objectId,
final TrustEvidenceType type, final Date timestamp,
final Serializable info, final TrustedEntityId sourceId) {
if (subjectId == null)
throw new NullPointerException("subjectId can't be null");
if (objectId == null)
throw new NullPointerException("objectId can't be null");
if (type == null)
throw new NullPointerException("type can't be null");
if (timestamp == null)
throw new NullPointerException("timestamp can't be null");
if (info instanceof Double && ((Double) info < 0.0d || (Double) info > 1.0d))
throw new IllegalArgumentException("info (rating) is out of range [0,1]");
this.subjectId = subjectId;
this.objectId = objectId;
this.type = type;
this.timestamp = timestamp;
this.info = info;
this.sourceId = sourceId;
}
/**
* Returns the {@link TrustedEntityId} of the subject this piece of
* trust evidence refers to.
*
* @return the {@link TrustedEntityId} of the subject this piece of
* trust evidence refers to.
*/
public TrustedEntityId getSubjectId() {
return this.subjectId;
}
/**
* Returns the {@link TrustedEntityId} of the object this piece of
* trust evidence refers to.
*
* @return the {@link TrustedEntityId} of the object this piece of
* trust evidence refers to.
*/
public TrustedEntityId getObjectId() {
return this.objectId;
}
/**
* Returns the {@link TrustEvidenceType type} of this piece of trust
* evidence.
*
* @return the {@link TrustEvidenceType type} of this piece of trust
* evidence.
*/
public TrustEvidenceType getType() {
return this.type;
}
/**
* Returns the date and time when the trust value was last evaluated.
*
* @return the date and time when the trust value was last evaluated.
*/
public Date getTimestamp() {
return this.timestamp;
}
/**
* Returns the trust value expressing the trustworthiness of the identified
* trustee.
*
* @return the trust value expressing the trustworthiness of the identified
* trustee.
*/
public Serializable getInfo() {
return this.info;
}
/**
* Returns the {@link TrustedEntityId} of the source this piece of
* trust evidence originates from.
*
* @return the {@link TrustedEntityId} of the source this piece of
* trust evidence originates from.
*/
public TrustedEntityId getSourceId() {
return this.sourceId;
}
/*
* @see java.lang.Comparable#compareTo(java.lang.Object)
*/
@Override
public int compareTo(TrustEvidence that) {
if (that == null)
throw new NullPointerException("can't compare with null");
if (this == that)
return 0;
int comparison = this.timestamp.compareTo(that.timestamp);
if (comparison != 0)
return comparison;
comparison = this.subjectId.getEntityId().compareTo(that.subjectId.getEntityId());
if (comparison != 0)
return comparison;
comparison = this.objectId.getEntityId().compareTo(that.objectId.getEntityId());
if (comparison != 0)
return comparison;
comparison = this.type.compareTo(that.type);
if (comparison != 0)
return comparison;
if (this.info != null) {
if (that.info == null) { // this.info != null && that.info == null
return +1; // empty before evidence with info
} else { // this.info != null && that.info != null
if (this.info.hashCode() < that.info.hashCode())
return -1;
else if (this.info.hashCode() > that.info.hashCode())
return +1;
}
} else { // this.info == null
if (that.info == null) // this.info == null && that.info == null
return 0;
else // this.info == null && that.info != null
return -1; // empty before evidence with info
}
if (this.sourceId != null) {
if (that.sourceId == null) // this.sourceId != null && that.sourceId == null
return +1; // direct before indirect evidence
else // this.sourceId != null && that.sourceId != null
return this.sourceId.getEntityId().compareTo(that.sourceId.getEntityId());
} else { // sourceId == null
if (that.sourceId == null) // this.sourceId == null && that.sourceId == null
return 0;
else // this.sourceId == null && that.sourceId != null
return -1; // direct before indirect evidence
}
}
/**
* Returns a <code>String</code> representation of this piece of trust
* evidence.
*
* @return a <code>String</code> representation of this piece of trust
* evidence.
*/
@Override
public String toString() {
StringBuilder sb = new StringBuilder();
sb.append("TrustEvidence (subjectId=");
sb.append(this.subjectId);
sb.append(", objectId=");
sb.append(this.objectId);
sb.append(", type=");
sb.append(this.type);
sb.append(", timestamp=");
sb.append(this.timestamp);
sb.append(", info=");
sb.append(this.info);
sb.append(", sourceId=");
sb.append(this.sourceId);
sb.append(")");
return sb.toString();
}
/*
* @see java.lang.Object#hashCode()
*/
@Override
public int hashCode() {
final int prime = 31;
int result = 1;
result = prime * result
+ ((this.subjectId == null) ? 0 : this.subjectId.hashCode());
result = prime * result
+ ((this.objectId == null) ? 0 : this.objectId.hashCode());
result = prime * result
+ ((this.type == null) ? 0 : this.type.hashCode());
result = prime * result
+ ((this.timestamp == null) ? 0 : this.timestamp.hashCode());
result = prime * result
+ ((this.info == null) ? 0 : this.info.hashCode());
result = prime * result
+ ((this.sourceId == null) ? 0 : this.sourceId.hashCode());
return result;
}
/*
* @see java.lang.Object#equals(java.lang.Object)
*/
@Override
public boolean equals(Object that) {
if (this == that)
return true;
if (that == null)
return false;
if (this.getClass() != that.getClass())
return false;
TrustEvidence other = (TrustEvidence) that;
if (this.subjectId == null) {
if (other.subjectId != null)
return false;
} else if (!this.subjectId.equals(other.subjectId))
return false;
if (this.objectId == null) {
if (other.objectId != null)
return false;
} else if (!this.objectId.equals(other.objectId))
return false;
if (this.type != other.type)
return false;
if (this.timestamp == null) {
if (other.timestamp != null)
return false;
} else if (!this.timestamp.equals(other.timestamp))
return false;
if (this.info == null) {
if (other.info != null)
return false;
} else if (!this.info.equals(other.info))
return false;
if (this.sourceId == null) {
if (other.sourceId != null)
return false;
} else if (!this.sourceId.equals(other.sourceId))
return false;
return true;
}
}