1 /* 2 * Copyright (c) 2000, 2008, Oracle and/or its affiliates. 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. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 27 package javax.management.openmbean; 28 29 30 // java import 31 // 32 import java.util.Arrays; 33 34 import javax.management.Descriptor; 35 import javax.management.ImmutableDescriptor; 36 import javax.management.MBeanOperationInfo; 37 import javax.management.MBeanParameterInfo; 38 39 40 /** 41 * Describes an operation of an Open MBean. 42 * 43 * 44 * @since 1.5 45 */ 46 public class OpenMBeanOperationInfoSupport 47 extends MBeanOperationInfo 48 implements OpenMBeanOperationInfo { 49 50 /* Serial version */ 51 static final long serialVersionUID = 4996859732565369366L; 52 53 /** 54 * @serial The <i>open type</i> of the values returned by the operation 55 * described by this {@link OpenMBeanOperationInfo} instance 56 * 57 */ 58 private OpenType<?> returnOpenType; 59 60 61 // As this instance is immutable, 62 // these two values need only be calculated once. 63 private transient Integer myHashCode = null; 64 private transient String myToString = null; 65 66 67 /** 68 * <p>Constructs an {@code OpenMBeanOperationInfoSupport} 69 * instance, which describes the operation of a class of open 70 * MBeans, with the specified {@code name}, {@code description}, 71 * {@code signature}, {@code returnOpenType} and {@code 72 * impact}.</p> 73 * 74 * <p>The {@code signature} array parameter is internally copied, 75 * so that subsequent changes to the array referenced by {@code 76 * signature} have no effect on this instance.</p> 77 * 78 * @param name cannot be a null or empty string. 79 * 80 * @param description cannot be a null or empty string. 81 * 82 * @param signature can be null or empty if there are no 83 * parameters to describe. 84 * 85 * @param returnOpenType cannot be null: use {@code 86 * SimpleType.VOID} for operations that return nothing. 87 * 88 * @param impact must be one of {@code ACTION}, {@code 89 * ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}. 90 * 91 * @throws IllegalArgumentException if {@code name} or {@code 92 * description} are null or empty string, or {@code 93 * returnOpenType} is null, or {@code impact} is not one of {@code 94 * ACTION}, {@code ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}. 95 * 96 * @throws ArrayStoreException If {@code signature} is not an 97 * array of instances of a subclass of {@code MBeanParameterInfo}. 98 */ 99 public OpenMBeanOperationInfoSupport(String name, 100 String description, 101 OpenMBeanParameterInfo[] signature, 102 OpenType<?> returnOpenType, 103 int impact) { 104 this(name, description, signature, returnOpenType, impact, 105 (Descriptor) null); 106 } 107 108 /** 109 * <p>Constructs an {@code OpenMBeanOperationInfoSupport} 110 * instance, which describes the operation of a class of open 111 * MBeans, with the specified {@code name}, {@code description}, 112 * {@code signature}, {@code returnOpenType}, {@code 113 * impact}, and {@code descriptor}.</p> 114 * 115 * <p>The {@code signature} array parameter is internally copied, 116 * so that subsequent changes to the array referenced by {@code 117 * signature} have no effect on this instance.</p> 118 * 119 * @param name cannot be a null or empty string. 120 * 121 * @param description cannot be a null or empty string. 122 * 123 * @param signature can be null or empty if there are no 124 * parameters to describe. 125 * 126 * @param returnOpenType cannot be null: use {@code 127 * SimpleType.VOID} for operations that return nothing. 128 * 129 * @param impact must be one of {@code ACTION}, {@code 130 * ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}. 131 * 132 * @param descriptor The descriptor for the operation. This may 133 * be null, which is equivalent to an empty descriptor. 134 * 135 * @throws IllegalArgumentException if {@code name} or {@code 136 * description} are null or empty string, or {@code 137 * returnOpenType} is null, or {@code impact} is not one of {@code 138 * ACTION}, {@code ACTION_INFO}, {@code INFO}, or {@code UNKNOWN}. 139 * 140 * @throws ArrayStoreException If {@code signature} is not an 141 * array of instances of a subclass of {@code MBeanParameterInfo}. 142 * 143 * @since 1.6 144 */ 145 public OpenMBeanOperationInfoSupport(String name, 146 String description, 147 OpenMBeanParameterInfo[] signature, 148 OpenType<?> returnOpenType, 149 int impact, 150 Descriptor descriptor) { 151 super(name, 152 description, 153 arrayCopyCast(signature), 154 // must prevent NPE here - we will throw IAE later on if 155 // returnOpenType is null 156 (returnOpenType == null) ? null : returnOpenType.getClassName(), 157 impact, 158 ImmutableDescriptor.union(descriptor, 159 // must prevent NPE here - we will throw IAE later on if 160 // returnOpenType is null 161 (returnOpenType==null) ? null :returnOpenType.getDescriptor())); 162 163 // check parameters that should not be null or empty 164 // (unfortunately it is not done in superclass :-( ! ) 165 // 166 if (name == null || name.trim().equals("")) { 167 throw new IllegalArgumentException("Argument name cannot " + 168 "be null or empty"); 169 } 170 if (description == null || description.trim().equals("")) { 171 throw new IllegalArgumentException("Argument description cannot " + 172 "be null or empty"); 173 } 174 if (returnOpenType == null) { 175 throw new IllegalArgumentException("Argument returnOpenType " + 176 "cannot be null"); 177 } 178 179 if (impact != ACTION && impact != ACTION_INFO && impact != INFO && 180 impact != UNKNOWN) { 181 throw new IllegalArgumentException("Argument impact can only be " + 182 "one of ACTION, ACTION_INFO, " + 183 "INFO, or UNKNOWN: " + impact); 184 } 185 186 this.returnOpenType = returnOpenType; 187 } 188 189 190 // Converts an array of OpenMBeanParameterInfo objects extending 191 // MBeanParameterInfo into an array of MBeanParameterInfo. 192 // 193 private static MBeanParameterInfo[] 194 arrayCopyCast(OpenMBeanParameterInfo[] src) { 195 if (src == null) 196 return null; 197 198 MBeanParameterInfo[] dst = new MBeanParameterInfo[src.length]; 199 System.arraycopy(src, 0, dst, 0, src.length); 200 // may throw an ArrayStoreException 201 return dst; 202 } 203 204 // Converts an array of MBeanParameterInfo objects implementing 205 // OpenMBeanParameterInfo into an array of OpenMBeanParameterInfo. 206 // 207 private static OpenMBeanParameterInfo[] 208 arrayCopyCast(MBeanParameterInfo[] src) { 209 if (src == null) 210 return null; 211 212 OpenMBeanParameterInfo[] dst = new OpenMBeanParameterInfo[src.length]; 213 System.arraycopy(src, 0, dst, 0, src.length); 214 // may throw an ArrayStoreException 215 return dst; 216 } 217 218 219 // [JF]: should we add constructor with java.lang.reflect.Method 220 // method parameter ? would need to add consistency check between 221 // OpenType<?> returnOpenType and method.getReturnType(). 222 223 224 /** 225 * Returns the <i>open type</i> of the values returned by the 226 * operation described by this {@code OpenMBeanOperationInfo} 227 * instance. 228 */ 229 public OpenType<?> getReturnOpenType() { 230 231 return returnOpenType; 232 } 233 234 235 236 /* *** Commodity methods from java.lang.Object *** */ 237 238 239 /** 240 * <p>Compares the specified {@code obj} parameter with this 241 * {@code OpenMBeanOperationInfoSupport} instance for 242 * equality.</p> 243 * 244 * <p>Returns {@code true} if and only if all of the following 245 * statements are true: 246 * 247 * <ul> 248 * <li>{@code obj} is non null,</li> 249 * <li>{@code obj} also implements the {@code 250 * OpenMBeanOperationInfo} interface,</li> 251 * <li>their names are equal</li> 252 * <li>their signatures are equal</li> 253 * <li>their return open types are equal</li> 254 * <li>their impacts are equal</li> 255 * </ul> 256 * 257 * This ensures that this {@code equals} method works properly for 258 * {@code obj} parameters which are different implementations of 259 * the {@code OpenMBeanOperationInfo} interface. 260 * 261 * @param obj the object to be compared for equality with this 262 * {@code OpenMBeanOperationInfoSupport} instance; 263 * 264 * @return {@code true} if the specified object is equal to this 265 * {@code OpenMBeanOperationInfoSupport} instance. 266 */ 267 public boolean equals(Object obj) { 268 269 // if obj is null, return false 270 // 271 if (obj == null) { 272 return false; 273 } 274 275 // if obj is not a OpenMBeanOperationInfo, return false 276 // 277 OpenMBeanOperationInfo other; 278 try { 279 other = (OpenMBeanOperationInfo) obj; 280 } catch (ClassCastException e) { 281 return false; 282 } 283 284 // Now, really test for equality between this 285 // OpenMBeanOperationInfo implementation and the other: 286 // 287 288 // their Name should be equal 289 if ( ! this.getName().equals(other.getName()) ) { 290 return false; 291 } 292 293 // their Signatures should be equal 294 if ( ! Arrays.equals(this.getSignature(), other.getSignature()) ) { 295 return false; 296 } 297 298 // their return open types should be equal 299 if ( ! this.getReturnOpenType().equals(other.getReturnOpenType()) ) { 300 return false; 301 } 302 303 // their impacts should be equal 304 if ( this.getImpact() != other.getImpact() ) { 305 return false; 306 } 307 308 // All tests for equality were successfull 309 // 310 return true; 311 } 312 313 /** 314 * <p>Returns the hash code value for this {@code 315 * OpenMBeanOperationInfoSupport} instance.</p> 316 * 317 * <p>The hash code of an {@code OpenMBeanOperationInfoSupport} 318 * instance is the sum of the hash codes of all elements of 319 * information used in {@code equals} comparisons (ie: its name, 320 * return open type, impact and signature, where the signature 321 * hashCode is calculated by a call to {@code 322 * java.util.Arrays.asList(this.getSignature).hashCode()}).</p> 323 * 324 * <p>This ensures that {@code t1.equals(t2) } implies that {@code 325 * t1.hashCode()==t2.hashCode() } for any two {@code 326 * OpenMBeanOperationInfoSupport} instances {@code t1} and {@code 327 * t2}, as required by the general contract of the method {@link 328 * Object#hashCode() Object.hashCode()}.</p> 329 * 330 * <p>However, note that another instance of a class implementing 331 * the {@code OpenMBeanOperationInfo} interface may be equal to 332 * this {@code OpenMBeanOperationInfoSupport} instance as defined 333 * by {@link #equals(java.lang.Object)}, but may have a different 334 * hash code if it is calculated differently.</p> 335 * 336 * <p>As {@code OpenMBeanOperationInfoSupport} instances are 337 * immutable, the hash code for this instance is calculated once, 338 * on the first call to {@code hashCode}, and then the same value 339 * is returned for subsequent calls.</p> 340 * 341 * @return the hash code value for this {@code 342 * OpenMBeanOperationInfoSupport} instance 343 */ 344 public int hashCode() { 345 346 // Calculate the hash code value if it has not yet been done 347 // (ie 1st call to hashCode()) 348 // 349 if (myHashCode == null) { 350 int value = 0; 351 value += this.getName().hashCode(); 352 value += Arrays.asList(this.getSignature()).hashCode(); 353 value += this.getReturnOpenType().hashCode(); 354 value += this.getImpact(); 355 myHashCode = Integer.valueOf(value); 356 } 357 358 // return always the same hash code for this instance (immutable) 359 // 360 return myHashCode.intValue(); 361 } 362 363 /** 364 * <p>Returns a string representation of this {@code 365 * OpenMBeanOperationInfoSupport} instance.</p> 366 * 367 * <p>The string representation consists of the name of this class 368 * (ie {@code 369 * javax.management.openmbean.OpenMBeanOperationInfoSupport}), and 370 * the name, signature, return open type and impact of the 371 * described operation and the string representation of its descriptor.</p> 372 * 373 * <p>As {@code OpenMBeanOperationInfoSupport} instances are 374 * immutable, the string representation for this instance is 375 * calculated once, on the first call to {@code toString}, and 376 * then the same value is returned for subsequent calls.</p> 377 * 378 * @return a string representation of this {@code 379 * OpenMBeanOperationInfoSupport} instance 380 */ 381 public String toString() { 382 383 // Calculate the hash code value if it has not yet been done 384 // (ie 1st call to toString()) 385 // 386 if (myToString == null) { 387 myToString = new StringBuilder() 388 .append(this.getClass().getName()) 389 .append("(name=") 390 .append(this.getName()) 391 .append(",signature=") 392 .append(Arrays.asList(this.getSignature()).toString()) 393 .append(",return=") 394 .append(this.getReturnOpenType().toString()) 395 .append(",impact=") 396 .append(this.getImpact()) 397 .append(",descriptor=") 398 .append(this.getDescriptor()) 399 .append(")") 400 .toString(); 401 } 402 403 // return always the same string representation for this 404 // instance (immutable) 405 // 406 return myToString; 407 } 408 409 /** 410 * An object serialized in a version of the API before Descriptors were 411 * added to this class will have an empty or null Descriptor. 412 * For consistency with our 413 * behavior in this version, we must replace the object with one 414 * where the Descriptors reflect the same value of returned openType. 415 **/ 416 private Object readResolve() { 417 if (getDescriptor().getFieldNames().length == 0) { 418 // This constructor will construct the expected default Descriptor. 419 // 420 return new OpenMBeanOperationInfoSupport( 421 name, description, arrayCopyCast(getSignature()), 422 returnOpenType, getImpact()); 423 } else 424 return this; 425 } 426 427 }