001 /* 002 $Id: Sequence.java,v 1.4 2005/04/12 16:38:42 jstrachan Exp $ 003 004 Copyright 2003 (C) James Strachan and Bob Mcwhirter. All Rights Reserved. 005 006 Redistribution and use of this software and associated documentation 007 ("Software"), with or without modification, are permitted provided 008 that the following conditions are met: 009 010 1. Redistributions of source code must retain copyright 011 statements and notices. Redistributions must also contain a 012 copy of this document. 013 014 2. Redistributions in binary form must reproduce the 015 above copyright notice, this list of conditions and the 016 following disclaimer in the documentation and/or other 017 materials provided with the distribution. 018 019 3. The name "groovy" must not be used to endorse or promote 020 products derived from this Software without prior written 021 permission of The Codehaus. For written permission, 022 please contact info@codehaus.org. 023 024 4. Products derived from this Software may not be called "groovy" 025 nor may "groovy" appear in their names without prior written 026 permission of The Codehaus. "groovy" is a registered 027 trademark of The Codehaus. 028 029 5. Due credit should be given to The Codehaus - 030 http://groovy.codehaus.org/ 031 032 THIS SOFTWARE IS PROVIDED BY THE CODEHAUS AND CONTRIBUTORS 033 ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT 034 NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND 035 FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL 036 THE CODEHAUS OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, 037 INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 038 (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 039 SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 040 HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 041 STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 042 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 043 OF THE POSSIBILITY OF SUCH DAMAGE. 044 045 */ 046 package groovy.lang; 047 048 import java.util.ArrayList; 049 import java.util.Collection; 050 import java.util.Iterator; 051 import java.util.List; 052 053 import org.codehaus.groovy.runtime.InvokerHelper; 054 055 /** 056 * Represents a sequence of objects which represents zero or many instances of 057 * of objects of a given type. The type can be ommitted in which case any type of 058 * object can be added. 059 * 060 * @author <a href="mailto:james@coredevelopers.net">James Strachan</a> 061 * @version $Revision: 1.4 $ 062 */ 063 public class Sequence extends ArrayList implements GroovyObject { 064 065 private MetaClass metaClass = InvokerHelper.getMetaClass(this); 066 private Class type; 067 private int hashCode; 068 069 public Sequence() { 070 this(null); 071 } 072 073 public Sequence(Class type) { 074 this.type = type; 075 } 076 077 public Sequence(Class type, List content) { 078 super(content.size()); 079 this.type = type; 080 addAll(content); 081 } 082 083 /** 084 * Sets the contents of this sequence to that 085 * of the given collection. 086 */ 087 public void set(Collection collection) { 088 checkCollectionType(collection); 089 clear(); 090 addAll(collection); 091 } 092 093 public boolean equals(Object that) { 094 if (that instanceof Sequence) { 095 return equals((Sequence) that); 096 } 097 return false; 098 } 099 100 public boolean equals(Sequence that) { 101 if (size() == that.size()) { 102 for (int i = 0; i < size(); i++) { 103 if (!InvokerHelper.compareEqual(this.get(i), that.get(i))) { 104 return false; 105 } 106 } 107 return true; 108 } 109 return false; 110 } 111 112 public int hashCode() { 113 if (hashCode == 0) { 114 for (int i = 0; i < size(); i++) { 115 Object value = get(i); 116 int hash = (value != null) ? value.hashCode() : 0xbabe; 117 hashCode ^= hash; 118 } 119 if (hashCode == 0) { 120 hashCode = 0xbabe; 121 } 122 } 123 return hashCode; 124 } 125 126 public int minimumSize() { 127 return 0; 128 } 129 130 /** 131 * @return the type of the elements in the sequence or null if there is no 132 * type constraint on this sequence 133 */ 134 public Class type() { 135 return type; 136 } 137 138 public void add(int index, Object element) { 139 checkType(element); 140 hashCode = 0; 141 super.add(index, element); 142 } 143 144 public boolean add(Object element) { 145 checkType(element); 146 hashCode = 0; 147 return super.add(element); 148 } 149 150 public boolean addAll(Collection c) { 151 checkCollectionType(c); 152 hashCode = 0; 153 return super.addAll(c); 154 } 155 156 public boolean addAll(int index, Collection c) { 157 checkCollectionType(c); 158 hashCode = 0; 159 return super.addAll(index, c); 160 } 161 162 public void clear() { 163 hashCode = 0; 164 super.clear(); 165 } 166 167 public Object remove(int index) { 168 hashCode = 0; 169 return super.remove(index); 170 } 171 172 protected void removeRange(int fromIndex, int toIndex) { 173 hashCode = 0; 174 super.removeRange(fromIndex, toIndex); 175 } 176 177 public Object set(int index, Object element) { 178 hashCode = 0; 179 return super.set(index, element); 180 } 181 182 // GroovyObject interface 183 //------------------------------------------------------------------------- 184 public Object invokeMethod(String name, Object args) { 185 try { 186 return getMetaClass().invokeMethod(this, name, args); 187 } 188 catch (MissingMethodException e) { 189 // lets apply the method to each item in the collection 190 List answer = new ArrayList(size()); 191 for (Iterator iter = iterator(); iter.hasNext(); ) { 192 Object element = iter.next(); 193 Object value = InvokerHelper.invokeMethod(element, name, args); 194 answer.add(value); 195 } 196 return answer; 197 } 198 } 199 200 public Object getProperty(String property) { 201 return getMetaClass().getProperty(this, property); 202 } 203 204 public void setProperty(String property, Object newValue) { 205 getMetaClass().setProperty(this, property, newValue); 206 } 207 208 public MetaClass getMetaClass() { 209 return metaClass; 210 } 211 212 public void setMetaClass(MetaClass metaClass) { 213 this.metaClass = metaClass; 214 } 215 216 // Implementation methods 217 //------------------------------------------------------------------------- 218 219 /** 220 * Checks that each member of the given collection are of the correct 221 * type 222 */ 223 protected void checkCollectionType(Collection c) { 224 if (type != null) { 225 for (Iterator iter = c.iterator(); iter.hasNext(); ) { 226 Object element = iter.next(); 227 checkType(element); 228 } 229 } 230 } 231 232 233 /** 234 * Checks that the given object instance is of the correct type 235 * otherwise a runtime exception is thrown 236 */ 237 protected void checkType(Object object) { 238 if (object == null) { 239 throw new NullPointerException("Sequences cannot contain null, use a List instead"); 240 } 241 if (type != null) { 242 if (!type.isInstance(object)) { 243 throw new IllegalArgumentException( 244 "Invalid type of argument for sequence of type: " 245 + type.getName() 246 + " cannot add object: " 247 + object); 248 } 249 } 250 } 251 }