001 //$HeadURL: svn+ssh://rbezema@svn.wald.intevation.org/deegree/base/branches/2.2_testing/src/org/deegree/model/feature/XLinkedFeatureProperty.java $
002 /*---------------- FILE HEADER ------------------------------------------
003
004 This file is part of deegree.
005 Copyright (C) 2001-2008 by:
006 EXSE, Department of Geography, University of Bonn
007 http://www.giub.uni-bonn.de/deegree/
008 lat/lon GmbH
009 http://www.lat-lon.de
010
011 This library is free software; you can redistribute it and/or
012 modify it under the terms of the GNU Lesser General Public
013 License as published by the Free Software Foundation; either
014 version 2.1 of the License, or (at your option) any later version.
015
016 This library is distributed in the hope that it will be useful,
017 but WITHOUT ANY WARRANTY; without even the implied warranty of
018 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
019 Lesser General Public License for more details.
020
021 You should have received a copy of the GNU Lesser General Public
022 License along with this library; if not, write to the Free Software
023 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
024
025 Contact:
026
027 Andreas Poth
028 lat/lon GmbH
029 Aennchenstraße 19
030 53177 Bonn
031 Germany
032 E-Mail: poth@lat-lon.de
033
034 Prof. Dr. Klaus Greve
035 Department of Geography
036 University of Bonn
037 Meckenheimer Allee 166
038 53115 Bonn
039 Germany
040 E-Mail: greve@giub.uni-bonn.de
041
042 ---------------------------------------------------------------------------*/
043 package org.deegree.model.feature;
044
045 import org.deegree.datatypes.QualifiedName;
046
047 /**
048 * Feature property instance that does not specify it's content inline, but references a feature
049 * instance via an XLink.
050 *
051 * @author <a href="mailto:schneider@lat-lon.de">Markus Schneider </a>
052 * @author last edited by: $Author: apoth $
053 *
054 * @version $Revision: 9343 $, $Date: 2007-12-27 14:30:32 +0100 (Do, 27 Dez 2007) $
055 */
056 public class XLinkedFeatureProperty implements FeatureProperty {
057
058 private QualifiedName name;
059
060 private String targetFeatureId;
061
062 private Feature targetFeature;
063
064 /**
065 * Creates a new instance of <code>XLinkedFeatureProperty</code> from the given parameters.
066 * <p>
067 * NOTE: After creating, this property has no value. The reference to the target feature has to
068 * be resolved first by calling #setValue(java.lang.Object).
069 *
070 * @see #setValue(java.lang.Object)
071 *
072 * @param name
073 * feature name
074 * @param targetFeatureId
075 * id of the feature that this property contains
076 */
077 public XLinkedFeatureProperty( QualifiedName name, String targetFeatureId ) {
078 this.name = name;
079 this.targetFeatureId = targetFeatureId;
080 }
081
082 /**
083 * Returns the name of the property.
084 *
085 * @return the name of the property.
086 */
087 public QualifiedName getName() {
088 return this.name;
089 }
090
091 /**
092 * Returns the value of the property.
093 *
094 * @return the value of the property.
095 */
096 public Object getValue() {
097 checkResolved();
098 return this.targetFeature;
099 }
100
101 /**
102 * Returns the value of the property.
103 *
104 * @return the value of the property.
105 */
106 public Object getValue( Object defaultValue ) {
107 checkResolved();
108 if ( this.targetFeature == null ) {
109 return defaultValue;
110 }
111 return this.targetFeature;
112 }
113
114 /**
115 * Sets the target feature instance that this feature property refers to.
116 *
117 * @param value
118 * feature instance that this feature property refers to
119 * @throws RuntimeException
120 * if the reference has already been resolved
121 */
122 public void setValue( Object value ) {
123 if ( this.targetFeature != null ) {
124 String msg = Messages.format( "ERROR_REFERENCE_ALREADY_RESOLVED", this.targetFeatureId );
125 throw new RuntimeException( msg );
126 }
127 this.targetFeature = (Feature) value;
128 }
129
130 /*
131 * (non-Javadoc)
132 *
133 * @see org.deegree.model.feature.FeatureProperty#getOwner()
134 */
135 public Feature getOwner() {
136 return null;
137 }
138
139 /**
140 * Returns the feature id of the target feature.
141 *
142 * @return the feature id of the target feature.
143 */
144 public String getTargetFeatureId() {
145 return this.targetFeatureId;
146 }
147
148 /**
149 * Ensures that the reference to the target feature has been resolved.
150 *
151 * @throws RuntimeException
152 * if the reference has not been resolved
153 */
154 private void checkResolved() {
155 if ( this.targetFeature == null ) {
156 String msg = Messages.format( "ERROR_XLINK_NOT_RESOLVED", this.targetFeatureId );
157 throw new RuntimeException( msg );
158 }
159 }
160 }