J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2007 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | |
| 27 | package javax.management.openmbean; |
| 28 | |
| 29 | |
| 30 | // java import |
| 31 | // |
| 32 | import java.util.ArrayList; |
| 33 | import java.util.Collections; |
| 34 | import java.util.Iterator; |
| 35 | import java.util.List; |
| 36 | |
| 37 | // jmx import |
| 38 | // |
| 39 | |
| 40 | |
| 41 | /** |
| 42 | * The <code>TabularType</code> class is the <i> open type</i> class |
| 43 | * whose instances describe the types of {@link TabularData <code>TabularData</code>} values. |
| 44 | * |
| 45 | * @since 1.5 |
| 46 | */ |
| 47 | public class TabularType extends OpenType<TabularData> { |
| 48 | |
| 49 | /* Serial version */ |
| 50 | static final long serialVersionUID = 6554071860220659261L; |
| 51 | |
| 52 | |
| 53 | /** |
| 54 | * @serial The composite type of rows |
| 55 | */ |
| 56 | private CompositeType rowType; |
| 57 | |
| 58 | /** |
| 59 | * @serial The items used to index each row element, kept in the order the user gave |
| 60 | * This is an unmodifiable {@link ArrayList} |
| 61 | */ |
| 62 | private List<String> indexNames; |
| 63 | |
| 64 | |
| 65 | private transient Integer myHashCode = null; // As this instance is immutable, these two values |
| 66 | private transient String myToString = null; // need only be calculated once. |
| 67 | |
| 68 | |
| 69 | /* *** Constructor *** */ |
| 70 | |
| 71 | /** |
| 72 | * Constructs a <code>TabularType</code> instance, checking for the validity of the given parameters. |
| 73 | * The validity constraints are described below for each parameter. |
| 74 | * <p> |
| 75 | * The Java class name of tabular data values this tabular type represents |
| 76 | * (ie the class name returned by the {@link OpenType#getClassName() getClassName} method) |
| 77 | * is set to the string value returned by <code>TabularData.class.getName()</code>. |
| 78 | * <p> |
| 79 | * @param typeName The name given to the tabular type this instance represents; cannot be a null or empty string. |
| 80 | * <br> |
| 81 | * @param description The human readable description of the tabular type this instance represents; |
| 82 | * cannot be a null or empty string. |
| 83 | * <br> |
| 84 | * @param rowType The type of the row elements of tabular data values described by this tabular type instance; |
| 85 | * cannot be null. |
| 86 | * <br> |
| 87 | * @param indexNames The names of the items the values of which are used to uniquely index each row element in the |
| 88 | * tabular data values described by this tabular type instance; |
| 89 | * cannot be null or empty. Each element should be an item name defined in <var>rowType</var> |
| 90 | * (no null or empty string allowed). |
| 91 | * It is important to note that the <b>order</b> of the item names in <var>indexNames</var> |
| 92 | * is used by the methods {@link TabularData#get(java.lang.Object[]) <code>get</code>} and |
| 93 | * {@link TabularData#remove(java.lang.Object[]) <code>remove</code>} of class |
| 94 | * <code>TabularData</code> to match their array of values parameter to items. |
| 95 | * <br> |
| 96 | * @throws IllegalArgumentException if <var>rowType</var> is null, |
| 97 | * or <var>indexNames</var> is a null or empty array, |
| 98 | * or an element in <var>indexNames</var> is a null or empty string, |
| 99 | * or <var>typeName</var> or <var>description</var> is a null or empty string. |
| 100 | * <br> |
| 101 | * @throws OpenDataException if an element's value of <var>indexNames</var> |
| 102 | * is not an item name defined in <var>rowType</var>. |
| 103 | */ |
| 104 | public TabularType(String typeName, |
| 105 | String description, |
| 106 | CompositeType rowType, |
| 107 | String[] indexNames) throws OpenDataException { |
| 108 | |
| 109 | // Check and initialize state defined by parent. |
| 110 | // |
| 111 | super(TabularData.class.getName(), typeName, description, false); |
| 112 | |
| 113 | // Check rowType is not null |
| 114 | // |
| 115 | if (rowType == null) { |
| 116 | throw new IllegalArgumentException("Argument rowType cannot be null."); |
| 117 | } |
| 118 | |
| 119 | // Check indexNames is neither null nor empty and does not contain any null element or empty string |
| 120 | // |
| 121 | checkForNullElement(indexNames, "indexNames"); |
| 122 | checkForEmptyString(indexNames, "indexNames"); |
| 123 | |
| 124 | // Check all indexNames values are valid item names for rowType |
| 125 | // |
| 126 | for (int i=0; i<indexNames.length; i++) { |
| 127 | if ( ! rowType.containsKey(indexNames[i]) ) { |
| 128 | throw new OpenDataException("Argument's element value indexNames["+ i +"]=\""+ indexNames[i] + |
| 129 | "\" is not a valid item name for rowType."); |
| 130 | } |
| 131 | } |
| 132 | |
| 133 | // initialize rowType |
| 134 | // |
| 135 | this.rowType = rowType; |
| 136 | |
| 137 | // initialize indexNames (copy content so that subsequent |
| 138 | // modifs to the array referenced by the indexNames parameter |
| 139 | // have no impact) |
| 140 | // |
| 141 | List<String> tmpList = new ArrayList<String>(indexNames.length + 1); |
| 142 | for (int i=0; i<indexNames.length; i++) { |
| 143 | tmpList.add(indexNames[i]); |
| 144 | } |
| 145 | this.indexNames = Collections.unmodifiableList(tmpList); |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Checks that Object[] arg is neither null nor empty (ie length==0) |
| 150 | * and that it does not contain any null element. |
| 151 | */ |
| 152 | private static void checkForNullElement(Object[] arg, String argName) { |
| 153 | if ( (arg == null) || (arg.length == 0) ) { |
| 154 | throw new IllegalArgumentException("Argument "+ argName +"[] cannot be null or empty."); |
| 155 | } |
| 156 | for (int i=0; i<arg.length; i++) { |
| 157 | if (arg[i] == null) { |
| 158 | throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be null."); |
| 159 | } |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * Checks that String[] does not contain any empty (or blank characters only) string. |
| 165 | */ |
| 166 | private static void checkForEmptyString(String[] arg, String argName) { |
| 167 | for (int i=0; i<arg.length; i++) { |
| 168 | if (arg[i].trim().equals("")) { |
| 169 | throw new IllegalArgumentException("Argument's element "+ argName +"["+ i +"] cannot be an empty string."); |
| 170 | } |
| 171 | } |
| 172 | } |
| 173 | |
| 174 | |
| 175 | /* *** Tabular type specific information methods *** */ |
| 176 | |
| 177 | /** |
| 178 | * Returns the type of the row elements of tabular data values |
| 179 | * described by this <code>TabularType</code> instance. |
| 180 | * |
| 181 | * @return the type of each row. |
| 182 | */ |
| 183 | public CompositeType getRowType() { |
| 184 | |
| 185 | return rowType; |
| 186 | } |
| 187 | |
| 188 | /** |
| 189 | * <p>Returns, in the same order as was given to this instance's |
| 190 | * constructor, an unmodifiable List of the names of the items the |
| 191 | * values of which are used to uniquely index each row element of |
| 192 | * tabular data values described by this <code>TabularType</code> |
| 193 | * instance.</p> |
| 194 | * |
| 195 | * @return a List of String representing the names of the index |
| 196 | * items. |
| 197 | * |
| 198 | */ |
| 199 | public List<String> getIndexNames() { |
| 200 | |
| 201 | return indexNames; |
| 202 | } |
| 203 | |
| 204 | /** |
| 205 | * Tests whether <var>obj</var> is a value which could be |
| 206 | * described by this <code>TabularType</code> instance. |
| 207 | * |
| 208 | * <p>If <var>obj</var> is null or is not an instance of |
| 209 | * <code>javax.management.openmbean.TabularData</code>, |
| 210 | * <code>isValue</code> returns <code>false</code>.</p> |
| 211 | * |
| 212 | * <p>If <var>obj</var> is an instance of |
| 213 | * <code>javax.management.openmbean.TabularData</code>, say {@code |
| 214 | * td}, the result is true if this {@code TabularType} is |
| 215 | * <em>assignable from</em> {@link TabularData#getTabularType() |
| 216 | * td.getTabularType()}, as defined in {@link |
| 217 | * CompositeType#isValue CompositeType.isValue}.</p> |
| 218 | * |
| 219 | * @param obj the value whose open type is to be tested for |
| 220 | * compatibility with this <code>TabularType</code> instance. |
| 221 | * |
| 222 | * @return <code>true</code> if <var>obj</var> is a value for this |
| 223 | * tabular type, <code>false</code> otherwise. |
| 224 | */ |
| 225 | public boolean isValue(Object obj) { |
| 226 | |
| 227 | // if obj is null or not a TabularData, return false |
| 228 | // |
| 229 | if (!(obj instanceof TabularData)) |
| 230 | return false; |
| 231 | |
| 232 | // if obj is not a TabularData, return false |
| 233 | // |
| 234 | TabularData value = (TabularData) obj; |
| 235 | TabularType valueType = value.getTabularType(); |
| 236 | return isAssignableFrom(valueType); |
| 237 | } |
| 238 | |
| 239 | @Override |
| 240 | boolean isAssignableFrom(OpenType ot) { |
| 241 | if (!(ot instanceof TabularType)) |
| 242 | return false; |
| 243 | TabularType tt = (TabularType) ot; |
| 244 | if (!getTypeName().equals(tt.getTypeName()) || |
| 245 | !getIndexNames().equals(tt.getIndexNames())) |
| 246 | return false; |
| 247 | return getRowType().isAssignableFrom(tt.getRowType()); |
| 248 | } |
| 249 | |
| 250 | |
| 251 | /* *** Methods overriden from class Object *** */ |
| 252 | |
| 253 | /** |
| 254 | * Compares the specified <code>obj</code> parameter with this <code>TabularType</code> instance for equality. |
| 255 | * <p> |
| 256 | * Two <code>TabularType</code> instances are equal if and only if all of the following statements are true: |
| 257 | * <ul> |
| 258 | * <li>their type names are equal</li> |
| 259 | * <li>their row types are equal</li> |
| 260 | * <li>they use the same index names, in the same order</li> |
| 261 | * </ul> |
| 262 | * <br> |
| 263 | * @param obj the object to be compared for equality with this <code>TabularType</code> instance; |
| 264 | * if <var>obj</var> is <code>null</code>, <code>equals</code> returns <code>false</code>. |
| 265 | * |
| 266 | * @return <code>true</code> if the specified object is equal to this <code>TabularType</code> instance. |
| 267 | */ |
| 268 | public boolean equals(Object obj) { |
| 269 | |
| 270 | // if obj is null, return false |
| 271 | // |
| 272 | if (obj == null) { |
| 273 | return false; |
| 274 | } |
| 275 | |
| 276 | // if obj is not a TabularType, return false |
| 277 | // |
| 278 | TabularType other; |
| 279 | try { |
| 280 | other = (TabularType) obj; |
| 281 | } catch (ClassCastException e) { |
| 282 | return false; |
| 283 | } |
| 284 | |
| 285 | // Now, really test for equality between this TabularType instance and the other: |
| 286 | // |
| 287 | |
| 288 | // their names should be equal |
| 289 | if ( ! this.getTypeName().equals(other.getTypeName()) ) { |
| 290 | return false; |
| 291 | } |
| 292 | |
| 293 | // their row types should be equal |
| 294 | if ( ! this.rowType.equals(other.rowType) ) { |
| 295 | return false; |
| 296 | } |
| 297 | |
| 298 | // their index names should be equal and in the same order (ensured by List.equals()) |
| 299 | if ( ! this.indexNames.equals(other.indexNames) ) { |
| 300 | return false; |
| 301 | } |
| 302 | |
| 303 | // All tests for equality were successfull |
| 304 | // |
| 305 | return true; |
| 306 | } |
| 307 | |
| 308 | /** |
| 309 | * Returns the hash code value for this <code>TabularType</code> instance. |
| 310 | * <p> |
| 311 | * The hash code of a <code>TabularType</code> instance is the sum of the hash codes |
| 312 | * of all elements of information used in <code>equals</code> comparisons |
| 313 | * (ie: name, row type, index names). |
| 314 | * This ensures that <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code> |
| 315 | * for any two <code>TabularType</code> instances <code>t1</code> and <code>t2</code>, |
| 316 | * as required by the general contract of the method |
| 317 | * {@link Object#hashCode() Object.hashCode()}. |
| 318 | * <p> |
| 319 | * As <code>TabularType</code> instances are immutable, the hash code for this instance is calculated once, |
| 320 | * on the first call to <code>hashCode</code>, and then the same value is returned for subsequent calls. |
| 321 | * |
| 322 | * @return the hash code value for this <code>TabularType</code> instance |
| 323 | */ |
| 324 | public int hashCode() { |
| 325 | |
| 326 | // Calculate the hash code value if it has not yet been done (ie 1st call to hashCode()) |
| 327 | // |
| 328 | if (myHashCode == null) { |
| 329 | int value = 0; |
| 330 | value += this.getTypeName().hashCode(); |
| 331 | value += this.rowType.hashCode(); |
| 332 | for (Iterator k = indexNames.iterator(); k.hasNext(); ) { |
| 333 | value += k.next().hashCode(); |
| 334 | } |
| 335 | myHashCode = new Integer(value); |
| 336 | } |
| 337 | |
| 338 | // return always the same hash code for this instance (immutable) |
| 339 | // |
| 340 | return myHashCode.intValue(); |
| 341 | } |
| 342 | |
| 343 | /** |
| 344 | * Returns a string representation of this <code>TabularType</code> instance. |
| 345 | * <p> |
| 346 | * The string representation consists of the name of this class (ie <code>javax.management.openmbean.TabularType</code>), |
| 347 | * the type name for this instance, the row type string representation of this instance, |
| 348 | * and the index names of this instance. |
| 349 | * <p> |
| 350 | * As <code>TabularType</code> instances are immutable, the string representation for this instance is calculated once, |
| 351 | * on the first call to <code>toString</code>, and then the same value is returned for subsequent calls. |
| 352 | * |
| 353 | * @return a string representation of this <code>TabularType</code> instance |
| 354 | */ |
| 355 | public String toString() { |
| 356 | |
| 357 | // Calculate the string representation if it has not yet been done (ie 1st call to toString()) |
| 358 | // |
| 359 | if (myToString == null) { |
| 360 | final StringBuilder result = new StringBuilder() |
| 361 | .append(this.getClass().getName()) |
| 362 | .append("(name=") |
| 363 | .append(getTypeName()) |
| 364 | .append(",rowType=") |
| 365 | .append(rowType.toString()) |
| 366 | .append(",indexNames=("); |
| 367 | int i=0; |
| 368 | Iterator k = indexNames.iterator(); |
| 369 | while( k.hasNext() ) { |
| 370 | if (i > 0) result.append(","); |
| 371 | result.append(k.next().toString()); |
| 372 | i++; |
| 373 | } |
| 374 | result.append("))"); |
| 375 | myToString = result.toString(); |
| 376 | } |
| 377 | |
| 378 | // return always the same string representation for this instance (immutable) |
| 379 | // |
| 380 | return myToString; |
| 381 | } |
| 382 | |
| 383 | } |