J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2002-2007 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 | package javax.management; |
| 27 | |
| 28 | import static com.sun.jmx.defaults.JmxProperties.MISC_LOGGER; |
| 29 | import com.sun.jmx.mbeanserver.DescriptorCache; |
| 30 | import com.sun.jmx.mbeanserver.Introspector; |
| 31 | import com.sun.jmx.mbeanserver.MBeanSupport; |
| 32 | import com.sun.jmx.mbeanserver.MXBeanSupport; |
| 33 | import com.sun.jmx.mbeanserver.StandardMBeanSupport; |
| 34 | import com.sun.jmx.mbeanserver.Util; |
| 35 | |
| 36 | import java.io.PrintWriter; |
| 37 | import java.io.StringWriter; |
| 38 | import java.security.AccessController; |
| 39 | import java.security.PrivilegedAction; |
| 40 | import java.util.HashMap; |
| 41 | import java.util.Map; |
| 42 | import java.util.WeakHashMap; |
| 43 | import java.util.logging.Level; |
| 44 | import javax.management.openmbean.OpenMBeanAttributeInfo; |
| 45 | import javax.management.openmbean.OpenMBeanAttributeInfoSupport; |
| 46 | import javax.management.openmbean.OpenMBeanConstructorInfo; |
| 47 | import javax.management.openmbean.OpenMBeanConstructorInfoSupport; |
| 48 | import javax.management.openmbean.OpenMBeanOperationInfo; |
| 49 | import javax.management.openmbean.OpenMBeanOperationInfoSupport; |
| 50 | import javax.management.openmbean.OpenMBeanParameterInfo; |
| 51 | import javax.management.openmbean.OpenMBeanParameterInfoSupport; |
| 52 | |
| 53 | /** |
| 54 | * <p>An MBean whose management interface is determined by reflection |
| 55 | * on a Java interface.</p> |
| 56 | * |
| 57 | * <p>This class brings more flexibility to the notion of Management |
| 58 | * Interface in the use of Standard MBeans. Straightforward use of |
| 59 | * the patterns for Standard MBeans described in the JMX Specification |
| 60 | * means that there is a fixed relationship between the implementation |
| 61 | * class of an MBean and its management interface (i.e., if the |
| 62 | * implementation class is Thing, the management interface must be |
| 63 | * ThingMBean). This class makes it possible to keep the convenience |
| 64 | * of specifying the management interface with a Java interface, |
| 65 | * without requiring that there be any naming relationship between the |
| 66 | * implementation and interface classes.</p> |
| 67 | * |
| 68 | * <p>By making a DynamicMBean out of an MBean, this class makes |
| 69 | * it possible to select any interface implemented by the MBean as its |
| 70 | * management interface, provided that it complies with JMX patterns |
| 71 | * (i.e., attributes defined by getter/setter etc...).</p> |
| 72 | * |
| 73 | * <p> This class also provides hooks that make it possible to supply |
| 74 | * custom descriptions and names for the {@link MBeanInfo} returned by |
| 75 | * the DynamicMBean interface.</p> |
| 76 | * |
| 77 | * <p>Using this class, an MBean can be created with any |
| 78 | * implementation class name <i>Impl</i> and with a management |
| 79 | * interface defined (as for current Standard MBeans) by any interface |
| 80 | * <i>Intf</i>, in one of two general ways:</p> |
| 81 | * |
| 82 | * <ul> |
| 83 | * |
| 84 | * <li>Using the public constructor |
| 85 | * {@link #StandardMBean(java.lang.Object, java.lang.Class, boolean) |
| 86 | * StandardMBean(impl,interface)}: |
| 87 | * <pre> |
| 88 | * MBeanServer mbs; |
| 89 | * ... |
| 90 | * Impl impl = new Impl(...); |
| 91 | * StandardMBean mbean = new StandardMBean(impl, Intf.class, false); |
| 92 | * mbs.registerMBean(mbean, objectName); |
| 93 | * </pre></li> |
| 94 | * |
| 95 | * <li>Subclassing StandardMBean: |
| 96 | * <pre> |
| 97 | * public class Impl extends StandardMBean implements Intf { |
| 98 | * public Impl() { |
| 99 | * super(Intf.class, false); |
| 100 | * } |
| 101 | * // implement methods of Intf |
| 102 | * } |
| 103 | * |
| 104 | * [...] |
| 105 | * |
| 106 | * MBeanServer mbs; |
| 107 | * .... |
| 108 | * Impl impl = new Impl(); |
| 109 | * mbs.registerMBean(impl, objectName); |
| 110 | * </pre></li> |
| 111 | * |
| 112 | * </ul> |
| 113 | * |
| 114 | * <p>In either case, the class <i>Impl</i> must implement the |
| 115 | * interface <i>Intf</i>.</p> |
| 116 | * |
| 117 | * <p>Standard MBeans based on the naming relationship between |
| 118 | * implementation and interface classes are of course still |
| 119 | * available.</p> |
| 120 | * |
| 121 | * <p>This class may also be used to construct MXBeans. The usage |
| 122 | * is exactly the same as for Standard MBeans except that in the |
| 123 | * examples above, the {@code false} parameter to the constructor or |
| 124 | * {@code super(...)} invocation is instead {@code true}.</p> |
| 125 | * |
| 126 | * @since 1.5 |
| 127 | */ |
| 128 | public class StandardMBean implements DynamicMBean, MBeanRegistration { |
| 129 | |
| 130 | private final static DescriptorCache descriptors = |
| 131 | DescriptorCache.getInstance(JMX.proof); |
| 132 | |
| 133 | /** |
| 134 | * The DynamicMBean that wraps the MXBean or Standard MBean implementation. |
| 135 | **/ |
| 136 | private volatile MBeanSupport<?> mbean; |
| 137 | |
| 138 | /** |
| 139 | * The cached MBeanInfo. |
| 140 | **/ |
| 141 | private volatile MBeanInfo cachedMBeanInfo; |
| 142 | |
| 143 | /** |
| 144 | * Make a DynamicMBean out of <var>implementation</var>, using the |
| 145 | * specified <var>mbeanInterface</var> class. |
| 146 | * @param implementation The implementation of this MBean. |
| 147 | * If <code>null</code>, and null implementation is allowed, |
| 148 | * then the implementation is assumed to be <var>this</var>. |
| 149 | * @param mbeanInterface The Management Interface exported by this |
| 150 | * MBean's implementation. If <code>null</code>, then this |
| 151 | * object will use standard JMX design pattern to determine |
| 152 | * the management interface associated with the given |
| 153 | * implementation. |
| 154 | * @param nullImplementationAllowed <code>true</code> if a null |
| 155 | * implementation is allowed. If null implementation is allowed, |
| 156 | * and a null implementation is passed, then the implementation |
| 157 | * is assumed to be <var>this</var>. |
| 158 | * @exception IllegalArgumentException if the given |
| 159 | * <var>implementation</var> is null, and null is not allowed. |
| 160 | **/ |
| 161 | private <T> void construct(T implementation, Class<T> mbeanInterface, |
| 162 | boolean nullImplementationAllowed, |
| 163 | boolean isMXBean) |
| 164 | throws NotCompliantMBeanException { |
| 165 | if (implementation == null) { |
| 166 | // Have to use (T)this rather than mbeanInterface.cast(this) |
| 167 | // because mbeanInterface might be null. |
| 168 | if (nullImplementationAllowed) |
| 169 | implementation = Util.<T>cast(this); |
| 170 | else throw new IllegalArgumentException("implementation is null"); |
| 171 | } |
| 172 | if (isMXBean) { |
| 173 | if (mbeanInterface == null) { |
| 174 | mbeanInterface = Util.cast(Introspector.getMXBeanInterface( |
| 175 | implementation.getClass())); |
| 176 | } |
| 177 | this.mbean = new MXBeanSupport(implementation, mbeanInterface); |
| 178 | } else { |
| 179 | if (mbeanInterface == null) { |
| 180 | mbeanInterface = Util.cast(Introspector.getStandardMBeanInterface( |
| 181 | implementation.getClass())); |
| 182 | } |
| 183 | this.mbean = |
| 184 | new StandardMBeanSupport(implementation, mbeanInterface); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | /** |
| 189 | * <p>Make a DynamicMBean out of the object |
| 190 | * <var>implementation</var>, using the specified |
| 191 | * <var>mbeanInterface</var> class.</p> |
| 192 | * |
| 193 | * @param implementation The implementation of this MBean. |
| 194 | * @param mbeanInterface The Management Interface exported by this |
| 195 | * MBean's implementation. If <code>null</code>, then this |
| 196 | * object will use standard JMX design pattern to determine |
| 197 | * the management interface associated with the given |
| 198 | * implementation. |
| 199 | * @param <T> Allows the compiler to check |
| 200 | * that {@code implementation} does indeed implement the class |
| 201 | * described by {@code mbeanInterface}. The compiler can only |
| 202 | * check this if {@code mbeanInterface} is a class literal such |
| 203 | * as {@code MyMBean.class}. |
| 204 | * |
| 205 | * @exception IllegalArgumentException if the given |
| 206 | * <var>implementation</var> is null. |
| 207 | * @exception NotCompliantMBeanException if the <var>mbeanInterface</var> |
| 208 | * does not follow JMX design patterns for Management Interfaces, or |
| 209 | * if the given <var>implementation</var> does not implement the |
| 210 | * specified interface. |
| 211 | **/ |
| 212 | public <T> StandardMBean(T implementation, Class<T> mbeanInterface) |
| 213 | throws NotCompliantMBeanException { |
| 214 | construct(implementation, mbeanInterface, false, false); |
| 215 | } |
| 216 | |
| 217 | /** |
| 218 | * <p>Make a DynamicMBean out of <var>this</var>, using the specified |
| 219 | * <var>mbeanInterface</var> class.</p> |
| 220 | * |
| 221 | * <p>Call {@link #StandardMBean(java.lang.Object, java.lang.Class) |
| 222 | * this(this,mbeanInterface)}. |
| 223 | * This constructor is reserved to subclasses.</p> |
| 224 | * |
| 225 | * @param mbeanInterface The Management Interface exported by this |
| 226 | * MBean. |
| 227 | * |
| 228 | * @exception NotCompliantMBeanException if the <var>mbeanInterface</var> |
| 229 | * does not follow JMX design patterns for Management Interfaces, or |
| 230 | * if <var>this</var> does not implement the specified interface. |
| 231 | **/ |
| 232 | protected StandardMBean(Class<?> mbeanInterface) |
| 233 | throws NotCompliantMBeanException { |
| 234 | construct(null, mbeanInterface, true, false); |
| 235 | } |
| 236 | |
| 237 | /** |
| 238 | * <p>Make a DynamicMBean out of the object |
| 239 | * <var>implementation</var>, using the specified |
| 240 | * <var>mbeanInterface</var> class. This constructor can be used |
| 241 | * to make either Standard MBeans or MXBeans. Unlike the |
| 242 | * constructor {@link #StandardMBean(Object, Class)}, it |
| 243 | * does not throw NotCompliantMBeanException.</p> |
| 244 | * |
| 245 | * @param implementation The implementation of this MBean. |
| 246 | * @param mbeanInterface The Management Interface exported by this |
| 247 | * MBean's implementation. If <code>null</code>, then this |
| 248 | * object will use standard JMX design pattern to determine |
| 249 | * the management interface associated with the given |
| 250 | * implementation. |
| 251 | * @param isMXBean If true, the {@code mbeanInterface} parameter |
| 252 | * names an MXBean interface and the resultant MBean is an MXBean. |
| 253 | * @param <T> Allows the compiler to check |
| 254 | * that {@code implementation} does indeed implement the class |
| 255 | * described by {@code mbeanInterface}. The compiler can only |
| 256 | * check this if {@code mbeanInterface} is a class literal such |
| 257 | * as {@code MyMBean.class}. |
| 258 | * |
| 259 | * @exception IllegalArgumentException if the given |
| 260 | * <var>implementation</var> is null, or if the <var>mbeanInterface</var> |
| 261 | * does not follow JMX design patterns for Management Interfaces, or |
| 262 | * if the given <var>implementation</var> does not implement the |
| 263 | * specified interface. |
| 264 | * |
| 265 | * @since 1.6 |
| 266 | **/ |
| 267 | public <T> StandardMBean(T implementation, Class<T> mbeanInterface, |
| 268 | boolean isMXBean) { |
| 269 | try { |
| 270 | construct(implementation, mbeanInterface, false, isMXBean); |
| 271 | } catch (NotCompliantMBeanException e) { |
| 272 | throw new IllegalArgumentException(e); |
| 273 | } |
| 274 | } |
| 275 | |
| 276 | /** |
| 277 | * <p>Make a DynamicMBean out of <var>this</var>, using the specified |
| 278 | * <var>mbeanInterface</var> class. This constructor can be used |
| 279 | * to make either Standard MBeans or MXBeans. Unlike the |
| 280 | * constructor {@link #StandardMBean(Object, Class)}, it |
| 281 | * does not throw NotCompliantMBeanException.</p> |
| 282 | * |
| 283 | * <p>Call {@link #StandardMBean(java.lang.Object, java.lang.Class, boolean) |
| 284 | * this(this, mbeanInterface, isMXBean)}. |
| 285 | * This constructor is reserved to subclasses.</p> |
| 286 | * |
| 287 | * @param mbeanInterface The Management Interface exported by this |
| 288 | * MBean. |
| 289 | * @param isMXBean If true, the {@code mbeanInterface} parameter |
| 290 | * names an MXBean interface and the resultant MBean is an MXBean. |
| 291 | * |
| 292 | * @exception IllegalArgumentException if the <var>mbeanInterface</var> |
| 293 | * does not follow JMX design patterns for Management Interfaces, or |
| 294 | * if <var>this</var> does not implement the specified interface. |
| 295 | * |
| 296 | * @since 1.6 |
| 297 | **/ |
| 298 | protected StandardMBean(Class<?> mbeanInterface, boolean isMXBean) { |
| 299 | try { |
| 300 | construct(null, mbeanInterface, true, isMXBean); |
| 301 | } catch (NotCompliantMBeanException e) { |
| 302 | throw new IllegalArgumentException(e); |
| 303 | } |
| 304 | } |
| 305 | |
| 306 | /** |
| 307 | * <p>Replace the implementation object wrapped in this object.</p> |
| 308 | * |
| 309 | * @param implementation The new implementation of this Standard MBean |
| 310 | * (or MXBean). The <code>implementation</code> object must implement |
| 311 | * the Standard MBean (or MXBean) interface that was supplied when this |
| 312 | * <code>StandardMBean</code> was constructed. |
| 313 | * |
| 314 | * @exception IllegalArgumentException if the given |
| 315 | * <var>implementation</var> is null. |
| 316 | * |
| 317 | * @exception NotCompliantMBeanException if the given |
| 318 | * <var>implementation</var> does not implement the |
| 319 | * Standard MBean (or MXBean) interface that was |
| 320 | * supplied at construction. |
| 321 | * |
| 322 | * @see #getImplementation |
| 323 | **/ |
| 324 | public void setImplementation(Object implementation) |
| 325 | throws NotCompliantMBeanException { |
| 326 | |
| 327 | if (implementation == null) |
| 328 | throw new IllegalArgumentException("implementation is null"); |
| 329 | |
| 330 | if (isMXBean()) { |
| 331 | this.mbean = new MXBeanSupport(implementation, |
| 332 | Util.<Class<Object>>cast(getMBeanInterface())); |
| 333 | } else { |
| 334 | this.mbean = new StandardMBeanSupport(implementation, |
| 335 | Util.<Class<Object>>cast(getMBeanInterface())); |
| 336 | } |
| 337 | } |
| 338 | |
| 339 | /** |
| 340 | * Get the implementation of this Standard MBean (or MXBean). |
| 341 | * @return The implementation of this Standard MBean (or MXBean). |
| 342 | * |
| 343 | * @see #setImplementation |
| 344 | **/ |
| 345 | public Object getImplementation() { |
| 346 | return mbean.getResource(); |
| 347 | } |
| 348 | |
| 349 | /** |
| 350 | * Get the Management Interface of this Standard MBean (or MXBean). |
| 351 | * @return The management interface of this Standard MBean (or MXBean). |
| 352 | **/ |
| 353 | public final Class<?> getMBeanInterface() { |
| 354 | return mbean.getMBeanInterface(); |
| 355 | } |
| 356 | |
| 357 | /** |
| 358 | * Get the class of the implementation of this Standard MBean (or MXBean). |
| 359 | * @return The class of the implementation of this Standard MBean (or MXBean). |
| 360 | **/ |
| 361 | public Class<?> getImplementationClass() { |
| 362 | return mbean.getResource().getClass(); |
| 363 | } |
| 364 | |
| 365 | // ------------------------------------------------------------------ |
| 366 | // From the DynamicMBean interface. |
| 367 | // ------------------------------------------------------------------ |
| 368 | public Object getAttribute(String attribute) |
| 369 | throws AttributeNotFoundException, |
| 370 | MBeanException, |
| 371 | ReflectionException { |
| 372 | return mbean.getAttribute(attribute); |
| 373 | } |
| 374 | |
| 375 | // ------------------------------------------------------------------ |
| 376 | // From the DynamicMBean interface. |
| 377 | // ------------------------------------------------------------------ |
| 378 | public void setAttribute(Attribute attribute) |
| 379 | throws AttributeNotFoundException, |
| 380 | InvalidAttributeValueException, |
| 381 | MBeanException, |
| 382 | ReflectionException { |
| 383 | mbean.setAttribute(attribute); |
| 384 | } |
| 385 | |
| 386 | // ------------------------------------------------------------------ |
| 387 | // From the DynamicMBean interface. |
| 388 | // ------------------------------------------------------------------ |
| 389 | public AttributeList getAttributes(String[] attributes) { |
| 390 | return mbean.getAttributes(attributes); |
| 391 | } |
| 392 | |
| 393 | // ------------------------------------------------------------------ |
| 394 | // From the DynamicMBean interface. |
| 395 | // ------------------------------------------------------------------ |
| 396 | public AttributeList setAttributes(AttributeList attributes) { |
| 397 | return mbean.setAttributes(attributes); |
| 398 | } |
| 399 | |
| 400 | // ------------------------------------------------------------------ |
| 401 | // From the DynamicMBean interface. |
| 402 | // ------------------------------------------------------------------ |
| 403 | public Object invoke(String actionName, Object params[], String signature[]) |
| 404 | throws MBeanException, ReflectionException { |
| 405 | return mbean.invoke(actionName, params, signature); |
| 406 | } |
| 407 | |
| 408 | /** |
| 409 | * Get the {@link MBeanInfo} for this MBean. |
| 410 | * <p> |
| 411 | * This method implements |
| 412 | * {@link javax.management.DynamicMBean#getMBeanInfo() |
| 413 | * DynamicMBean.getMBeanInfo()}. |
| 414 | * <p> |
| 415 | * This method first calls {@link #getCachedMBeanInfo()} in order to |
| 416 | * retrieve the cached MBeanInfo for this MBean, if any. If the |
| 417 | * MBeanInfo returned by {@link #getCachedMBeanInfo()} is not null, |
| 418 | * then it is returned.<br> |
| 419 | * Otherwise, this method builds a default MBeanInfo for this MBean, |
| 420 | * using the Management Interface specified for this MBean. |
| 421 | * <p> |
| 422 | * While building the MBeanInfo, this method calls the customization |
| 423 | * hooks that make it possible for subclasses to supply their custom |
| 424 | * descriptions, parameter names, etc...<br> |
| 425 | * Finally, it calls {@link #cacheMBeanInfo(javax.management.MBeanInfo) |
| 426 | * cacheMBeanInfo()} in order to cache the new MBeanInfo. |
| 427 | * @return The cached MBeanInfo for that MBean, if not null, or a |
| 428 | * newly built MBeanInfo if none was cached. |
| 429 | **/ |
| 430 | public MBeanInfo getMBeanInfo() { |
| 431 | try { |
| 432 | final MBeanInfo cached = getCachedMBeanInfo(); |
| 433 | if (cached != null) return cached; |
| 434 | } catch (RuntimeException x) { |
| 435 | if (MISC_LOGGER.isLoggable(Level.FINEST)) { |
| 436 | MISC_LOGGER.logp(Level.FINEST, |
| 437 | MBeanServerFactory.class.getName(), "getMBeanInfo", |
| 438 | "Failed to get cached MBeanInfo", x); |
| 439 | } |
| 440 | } |
| 441 | |
| 442 | if (MISC_LOGGER.isLoggable(Level.FINER)) { |
| 443 | MISC_LOGGER.logp(Level.FINER, |
| 444 | MBeanServerFactory.class.getName(), "getMBeanInfo", |
| 445 | "Building MBeanInfo for " + |
| 446 | getImplementationClass().getName()); |
| 447 | } |
| 448 | |
| 449 | MBeanSupport msupport = mbean; |
| 450 | final MBeanInfo bi = msupport.getMBeanInfo(); |
| 451 | final Object impl = msupport.getResource(); |
| 452 | |
| 453 | final boolean immutableInfo = immutableInfo(this.getClass()); |
| 454 | |
| 455 | final String cname = getClassName(bi); |
| 456 | final String text = getDescription(bi); |
| 457 | final MBeanConstructorInfo[] ctors = getConstructors(bi,impl); |
| 458 | final MBeanAttributeInfo[] attrs = getAttributes(bi); |
| 459 | final MBeanOperationInfo[] ops = getOperations(bi); |
| 460 | final MBeanNotificationInfo[] ntfs = getNotifications(bi); |
| 461 | final Descriptor desc = getDescriptor(bi, immutableInfo); |
| 462 | |
| 463 | final MBeanInfo nmbi = new MBeanInfo( |
| 464 | cname, text, attrs, ctors, ops, ntfs, desc); |
| 465 | try { |
| 466 | cacheMBeanInfo(nmbi); |
| 467 | } catch (RuntimeException x) { |
| 468 | if (MISC_LOGGER.isLoggable(Level.FINEST)) { |
| 469 | MISC_LOGGER.logp(Level.FINEST, |
| 470 | MBeanServerFactory.class.getName(), "getMBeanInfo", |
| 471 | "Failed to cache MBeanInfo", x); |
| 472 | } |
| 473 | } |
| 474 | |
| 475 | return nmbi; |
| 476 | } |
| 477 | |
| 478 | /** |
| 479 | * Customization hook: |
| 480 | * Get the className that will be used in the MBeanInfo returned by |
| 481 | * this MBean. |
| 482 | * <br> |
| 483 | * Subclasses may redefine this method in order to supply their |
| 484 | * custom class name. The default implementation returns |
| 485 | * {@link MBeanInfo#getClassName() info.getClassName()}. |
| 486 | * @param info The default MBeanInfo derived by reflection. |
| 487 | * @return the class name for the new MBeanInfo. |
| 488 | **/ |
| 489 | protected String getClassName(MBeanInfo info) { |
| 490 | if (info == null) return getImplementationClass().getName(); |
| 491 | return info.getClassName(); |
| 492 | } |
| 493 | |
| 494 | /** |
| 495 | * Customization hook: |
| 496 | * Get the description that will be used in the MBeanInfo returned by |
| 497 | * this MBean. |
| 498 | * <br> |
| 499 | * Subclasses may redefine this method in order to supply their |
| 500 | * custom MBean description. The default implementation returns |
| 501 | * {@link MBeanInfo#getDescription() info.getDescription()}. |
| 502 | * @param info The default MBeanInfo derived by reflection. |
| 503 | * @return the description for the new MBeanInfo. |
| 504 | **/ |
| 505 | protected String getDescription(MBeanInfo info) { |
| 506 | if (info == null) return null; |
| 507 | return info.getDescription(); |
| 508 | } |
| 509 | |
| 510 | /** |
| 511 | * <p>Customization hook: |
| 512 | * Get the description that will be used in the MBeanFeatureInfo |
| 513 | * returned by this MBean.</p> |
| 514 | * |
| 515 | * <p>Subclasses may redefine this method in order to supply |
| 516 | * their custom description. The default implementation returns |
| 517 | * {@link MBeanFeatureInfo#getDescription() |
| 518 | * info.getDescription()}.</p> |
| 519 | * |
| 520 | * <p>This method is called by |
| 521 | * {@link #getDescription(MBeanAttributeInfo)}, |
| 522 | * {@link #getDescription(MBeanOperationInfo)}, |
| 523 | * {@link #getDescription(MBeanConstructorInfo)}.</p> |
| 524 | * |
| 525 | * @param info The default MBeanFeatureInfo derived by reflection. |
| 526 | * @return the description for the given MBeanFeatureInfo. |
| 527 | **/ |
| 528 | protected String getDescription(MBeanFeatureInfo info) { |
| 529 | if (info == null) return null; |
| 530 | return info.getDescription(); |
| 531 | } |
| 532 | |
| 533 | /** |
| 534 | * Customization hook: |
| 535 | * Get the description that will be used in the MBeanAttributeInfo |
| 536 | * returned by this MBean. |
| 537 | * |
| 538 | * <p>Subclasses may redefine this method in order to supply their |
| 539 | * custom description. The default implementation returns {@link |
| 540 | * #getDescription(MBeanFeatureInfo) |
| 541 | * getDescription((MBeanFeatureInfo) info)}. |
| 542 | * @param info The default MBeanAttributeInfo derived by reflection. |
| 543 | * @return the description for the given MBeanAttributeInfo. |
| 544 | **/ |
| 545 | protected String getDescription(MBeanAttributeInfo info) { |
| 546 | return getDescription((MBeanFeatureInfo)info); |
| 547 | } |
| 548 | |
| 549 | /** |
| 550 | * Customization hook: |
| 551 | * Get the description that will be used in the MBeanConstructorInfo |
| 552 | * returned by this MBean. |
| 553 | * <br> |
| 554 | * Subclasses may redefine this method in order to supply their |
| 555 | * custom description. |
| 556 | * The default implementation returns {@link |
| 557 | * #getDescription(MBeanFeatureInfo) |
| 558 | * getDescription((MBeanFeatureInfo) info)}. |
| 559 | * @param info The default MBeanConstructorInfo derived by reflection. |
| 560 | * @return the description for the given MBeanConstructorInfo. |
| 561 | **/ |
| 562 | protected String getDescription(MBeanConstructorInfo info) { |
| 563 | return getDescription((MBeanFeatureInfo)info); |
| 564 | } |
| 565 | |
| 566 | /** |
| 567 | * Customization hook: |
| 568 | * Get the description that will be used for the <var>sequence</var> |
| 569 | * MBeanParameterInfo of the MBeanConstructorInfo returned by this MBean. |
| 570 | * <br> |
| 571 | * Subclasses may redefine this method in order to supply their |
| 572 | * custom description. The default implementation returns |
| 573 | * {@link MBeanParameterInfo#getDescription() param.getDescription()}. |
| 574 | * |
| 575 | * @param ctor The default MBeanConstructorInfo derived by reflection. |
| 576 | * @param param The default MBeanParameterInfo derived by reflection. |
| 577 | * @param sequence The sequence number of the parameter considered |
| 578 | * ("0" for the first parameter, "1" for the second parameter, |
| 579 | * etc...). |
| 580 | * @return the description for the given MBeanParameterInfo. |
| 581 | **/ |
| 582 | protected String getDescription(MBeanConstructorInfo ctor, |
| 583 | MBeanParameterInfo param, |
| 584 | int sequence) { |
| 585 | if (param == null) return null; |
| 586 | return param.getDescription(); |
| 587 | } |
| 588 | |
| 589 | /** |
| 590 | * Customization hook: |
| 591 | * Get the name that will be used for the <var>sequence</var> |
| 592 | * MBeanParameterInfo of the MBeanConstructorInfo returned by this MBean. |
| 593 | * <br> |
| 594 | * Subclasses may redefine this method in order to supply their |
| 595 | * custom parameter name. The default implementation returns |
| 596 | * {@link MBeanParameterInfo#getName() param.getName()}. |
| 597 | * |
| 598 | * @param ctor The default MBeanConstructorInfo derived by reflection. |
| 599 | * @param param The default MBeanParameterInfo derived by reflection. |
| 600 | * @param sequence The sequence number of the parameter considered |
| 601 | * ("0" for the first parameter, "1" for the second parameter, |
| 602 | * etc...). |
| 603 | * @return the name for the given MBeanParameterInfo. |
| 604 | **/ |
| 605 | protected String getParameterName(MBeanConstructorInfo ctor, |
| 606 | MBeanParameterInfo param, |
| 607 | int sequence) { |
| 608 | if (param == null) return null; |
| 609 | return param.getName(); |
| 610 | } |
| 611 | |
| 612 | /** |
| 613 | * Customization hook: |
| 614 | * Get the description that will be used in the MBeanOperationInfo |
| 615 | * returned by this MBean. |
| 616 | * <br> |
| 617 | * Subclasses may redefine this method in order to supply their |
| 618 | * custom description. The default implementation returns |
| 619 | * {@link #getDescription(MBeanFeatureInfo) |
| 620 | * getDescription((MBeanFeatureInfo) info)}. |
| 621 | * @param info The default MBeanOperationInfo derived by reflection. |
| 622 | * @return the description for the given MBeanOperationInfo. |
| 623 | **/ |
| 624 | protected String getDescription(MBeanOperationInfo info) { |
| 625 | return getDescription((MBeanFeatureInfo)info); |
| 626 | } |
| 627 | |
| 628 | /** |
| 629 | * Customization hook: |
| 630 | * Get the <var>impact</var> flag of the operation that will be used in |
| 631 | * the MBeanOperationInfo returned by this MBean. |
| 632 | * <br> |
| 633 | * Subclasses may redefine this method in order to supply their |
| 634 | * custom impact flag. The default implementation returns |
| 635 | * {@link MBeanOperationInfo#getImpact() info.getImpact()}. |
| 636 | * @param info The default MBeanOperationInfo derived by reflection. |
| 637 | * @return the impact flag for the given MBeanOperationInfo. |
| 638 | **/ |
| 639 | protected int getImpact(MBeanOperationInfo info) { |
| 640 | if (info == null) return MBeanOperationInfo.UNKNOWN; |
| 641 | return info.getImpact(); |
| 642 | } |
| 643 | |
| 644 | /** |
| 645 | * Customization hook: |
| 646 | * Get the name that will be used for the <var>sequence</var> |
| 647 | * MBeanParameterInfo of the MBeanOperationInfo returned by this MBean. |
| 648 | * <br> |
| 649 | * Subclasses may redefine this method in order to supply their |
| 650 | * custom parameter name. The default implementation returns |
| 651 | * {@link MBeanParameterInfo#getName() param.getName()}. |
| 652 | * |
| 653 | * @param op The default MBeanOperationInfo derived by reflection. |
| 654 | * @param param The default MBeanParameterInfo derived by reflection. |
| 655 | * @param sequence The sequence number of the parameter considered |
| 656 | * ("0" for the first parameter, "1" for the second parameter, |
| 657 | * etc...). |
| 658 | * @return the name to use for the given MBeanParameterInfo. |
| 659 | **/ |
| 660 | protected String getParameterName(MBeanOperationInfo op, |
| 661 | MBeanParameterInfo param, |
| 662 | int sequence) { |
| 663 | if (param == null) return null; |
| 664 | return param.getName(); |
| 665 | } |
| 666 | |
| 667 | /** |
| 668 | * Customization hook: |
| 669 | * Get the description that will be used for the <var>sequence</var> |
| 670 | * MBeanParameterInfo of the MBeanOperationInfo returned by this MBean. |
| 671 | * <br> |
| 672 | * Subclasses may redefine this method in order to supply their |
| 673 | * custom description. The default implementation returns |
| 674 | * {@link MBeanParameterInfo#getDescription() param.getDescription()}. |
| 675 | * |
| 676 | * @param op The default MBeanOperationInfo derived by reflection. |
| 677 | * @param param The default MBeanParameterInfo derived by reflection. |
| 678 | * @param sequence The sequence number of the parameter considered |
| 679 | * ("0" for the first parameter, "1" for the second parameter, |
| 680 | * etc...). |
| 681 | * @return the description for the given MBeanParameterInfo. |
| 682 | **/ |
| 683 | protected String getDescription(MBeanOperationInfo op, |
| 684 | MBeanParameterInfo param, |
| 685 | int sequence) { |
| 686 | if (param == null) return null; |
| 687 | return param.getDescription(); |
| 688 | } |
| 689 | |
| 690 | /** |
| 691 | * Customization hook: |
| 692 | * Get the MBeanConstructorInfo[] that will be used in the MBeanInfo |
| 693 | * returned by this MBean. |
| 694 | * <br> |
| 695 | * By default, this method returns <code>null</code> if the wrapped |
| 696 | * implementation is not <var>this</var>. Indeed, if the wrapped |
| 697 | * implementation is not this object itself, it will not be possible |
| 698 | * to recreate a wrapped implementation by calling the implementation |
| 699 | * constructors through <code>MBeanServer.createMBean(...)</code>.<br> |
| 700 | * Otherwise, if the wrapped implementation is <var>this</var>, |
| 701 | * <var>ctors</var> is returned. |
| 702 | * <br> |
| 703 | * Subclasses may redefine this method in order to modify this |
| 704 | * behavior, if needed. |
| 705 | * @param ctors The default MBeanConstructorInfo[] derived by reflection. |
| 706 | * @param impl The wrapped implementation. If <code>null</code> is |
| 707 | * passed, the wrapped implementation is ignored and |
| 708 | * <var>ctors</var> is returned. |
| 709 | * @return the MBeanConstructorInfo[] for the new MBeanInfo. |
| 710 | **/ |
| 711 | protected MBeanConstructorInfo[] |
| 712 | getConstructors(MBeanConstructorInfo[] ctors, Object impl) { |
| 713 | if (ctors == null) return null; |
| 714 | if (impl != null && impl != this) return null; |
| 715 | return ctors; |
| 716 | } |
| 717 | |
| 718 | /** |
| 719 | * Customization hook: |
| 720 | * Get the MBeanNotificationInfo[] that will be used in the MBeanInfo |
| 721 | * returned by this MBean. |
| 722 | * <br> |
| 723 | * Subclasses may redefine this method in order to supply their |
| 724 | * custom notifications. |
| 725 | * @param info The default MBeanInfo derived by reflection. |
| 726 | * @return the MBeanNotificationInfo[] for the new MBeanInfo. |
| 727 | **/ |
| 728 | MBeanNotificationInfo[] getNotifications(MBeanInfo info) { |
| 729 | return null; |
| 730 | } |
| 731 | |
| 732 | /** |
| 733 | * <p>Get the Descriptor that will be used in the MBeanInfo |
| 734 | * returned by this MBean.</p> |
| 735 | * |
| 736 | * <p>Subclasses may redefine this method in order to supply |
| 737 | * their custom descriptor.</p> |
| 738 | * |
| 739 | * <p>The default implementation of this method returns a Descriptor |
| 740 | * that contains at least the field {@code interfaceClassName}, with |
| 741 | * value {@link #getMBeanInterface()}.getName(). It may also contain |
| 742 | * the field {@code immutableInfo}, with a value that is the string |
| 743 | * {@code "true"} if the implementation can determine that the |
| 744 | * {@code MBeanInfo} returned by {@link #getMBeanInfo()} will always |
| 745 | * be the same. It may contain other fields: fields defined by the |
| 746 | * JMX specification must have appropriate values, and other fields |
| 747 | * must follow the conventions for non-standard field names.</p> |
| 748 | * |
| 749 | * @param info The default MBeanInfo derived by reflection. |
| 750 | * @return the Descriptor for the new MBeanInfo. |
| 751 | */ |
| 752 | Descriptor getDescriptor(MBeanInfo info, boolean immutableInfo) { |
| 753 | ImmutableDescriptor desc = null; |
| 754 | if (info == null || |
| 755 | info.getDescriptor() == null || |
| 756 | info.getDescriptor().getFieldNames().length == 0) { |
| 757 | final String interfaceClassNameS = |
| 758 | "interfaceClassName=" + getMBeanInterface().getName(); |
| 759 | final String immutableInfoS = |
| 760 | "immutableInfo=" + immutableInfo; |
| 761 | desc = new ImmutableDescriptor(interfaceClassNameS, immutableInfoS); |
| 762 | desc = descriptors.get(desc); |
| 763 | } else { |
| 764 | Descriptor d = info.getDescriptor(); |
| 765 | Map<String,Object> fields = new HashMap<String,Object>(); |
| 766 | for (String fieldName : d.getFieldNames()) { |
| 767 | if (fieldName.equals("immutableInfo")) { |
| 768 | // Replace immutableInfo as the underlying MBean/MXBean |
| 769 | // could already implement NotificationBroadcaster and |
| 770 | // return immutableInfo=true in its MBeanInfo. |
| 771 | fields.put(fieldName, Boolean.toString(immutableInfo)); |
| 772 | } else { |
| 773 | fields.put(fieldName, d.getFieldValue(fieldName)); |
| 774 | } |
| 775 | } |
| 776 | desc = new ImmutableDescriptor(fields); |
| 777 | } |
| 778 | return desc; |
| 779 | } |
| 780 | |
| 781 | /** |
| 782 | * Customization hook: |
| 783 | * Return the MBeanInfo cached for this object. |
| 784 | * |
| 785 | * <p>Subclasses may redefine this method in order to implement their |
| 786 | * own caching policy. The default implementation stores one |
| 787 | * {@link MBeanInfo} object per instance. |
| 788 | * |
| 789 | * @return The cached MBeanInfo, or null if no MBeanInfo is cached. |
| 790 | * |
| 791 | * @see #cacheMBeanInfo(MBeanInfo) |
| 792 | **/ |
| 793 | protected MBeanInfo getCachedMBeanInfo() { |
| 794 | return cachedMBeanInfo; |
| 795 | } |
| 796 | |
| 797 | /** |
| 798 | * Customization hook: |
| 799 | * cache the MBeanInfo built for this object. |
| 800 | * |
| 801 | * <p>Subclasses may redefine this method in order to implement |
| 802 | * their own caching policy. The default implementation stores |
| 803 | * <code>info</code> in this instance. A subclass can define |
| 804 | * other policies, such as not saving <code>info</code> (so it is |
| 805 | * reconstructed every time {@link #getMBeanInfo()} is called) or |
| 806 | * sharing a unique {@link MBeanInfo} object when several |
| 807 | * <code>StandardMBean</code> instances have equal {@link |
| 808 | * MBeanInfo} values. |
| 809 | * |
| 810 | * @param info the new <code>MBeanInfo</code> to cache. Any |
| 811 | * previously cached value is discarded. This parameter may be |
| 812 | * null, in which case there is no new cached value. |
| 813 | **/ |
| 814 | protected void cacheMBeanInfo(MBeanInfo info) { |
| 815 | cachedMBeanInfo = info; |
| 816 | } |
| 817 | |
| 818 | private boolean isMXBean() { |
| 819 | return mbean.isMXBean(); |
| 820 | } |
| 821 | |
| 822 | private static <T> boolean identicalArrays(T[] a, T[] b) { |
| 823 | if (a == b) |
| 824 | return true; |
| 825 | if (a == null || b == null || a.length != b.length) |
| 826 | return false; |
| 827 | for (int i = 0; i < a.length; i++) { |
| 828 | if (a[i] != b[i]) |
| 829 | return false; |
| 830 | } |
| 831 | return true; |
| 832 | } |
| 833 | |
| 834 | private static <T> boolean equal(T a, T b) { |
| 835 | if (a == b) |
| 836 | return true; |
| 837 | if (a == null || b == null) |
| 838 | return false; |
| 839 | return a.equals(b); |
| 840 | } |
| 841 | |
| 842 | private static MBeanParameterInfo |
| 843 | customize(MBeanParameterInfo pi, |
| 844 | String name, |
| 845 | String description) { |
| 846 | if (equal(name, pi.getName()) && |
| 847 | equal(description, pi.getDescription())) |
| 848 | return pi; |
| 849 | else if (pi instanceof OpenMBeanParameterInfo) { |
| 850 | OpenMBeanParameterInfo opi = (OpenMBeanParameterInfo) pi; |
| 851 | return new OpenMBeanParameterInfoSupport(name, |
| 852 | description, |
| 853 | opi.getOpenType(), |
| 854 | pi.getDescriptor()); |
| 855 | } else { |
| 856 | return new MBeanParameterInfo(name, |
| 857 | pi.getType(), |
| 858 | description, |
| 859 | pi.getDescriptor()); |
| 860 | } |
| 861 | } |
| 862 | |
| 863 | private static MBeanConstructorInfo |
| 864 | customize(MBeanConstructorInfo ci, |
| 865 | String description, |
| 866 | MBeanParameterInfo[] signature) { |
| 867 | if (equal(description, ci.getDescription()) && |
| 868 | identicalArrays(signature, ci.getSignature())) |
| 869 | return ci; |
| 870 | if (ci instanceof OpenMBeanConstructorInfo) { |
| 871 | OpenMBeanParameterInfo[] oparams = |
| 872 | paramsToOpenParams(signature); |
| 873 | return new OpenMBeanConstructorInfoSupport(ci.getName(), |
| 874 | description, |
| 875 | oparams, |
| 876 | ci.getDescriptor()); |
| 877 | } else { |
| 878 | return new MBeanConstructorInfo(ci.getName(), |
| 879 | description, |
| 880 | signature, |
| 881 | ci.getDescriptor()); |
| 882 | } |
| 883 | } |
| 884 | |
| 885 | private static MBeanOperationInfo |
| 886 | customize(MBeanOperationInfo oi, |
| 887 | String description, |
| 888 | MBeanParameterInfo[] signature, |
| 889 | int impact) { |
| 890 | if (equal(description, oi.getDescription()) && |
| 891 | identicalArrays(signature, oi.getSignature()) && |
| 892 | impact == oi.getImpact()) |
| 893 | return oi; |
| 894 | if (oi instanceof OpenMBeanOperationInfo) { |
| 895 | OpenMBeanOperationInfo ooi = (OpenMBeanOperationInfo) oi; |
| 896 | OpenMBeanParameterInfo[] oparams = |
| 897 | paramsToOpenParams(signature); |
| 898 | return new OpenMBeanOperationInfoSupport(oi.getName(), |
| 899 | description, |
| 900 | oparams, |
| 901 | ooi.getReturnOpenType(), |
| 902 | impact, |
| 903 | oi.getDescriptor()); |
| 904 | } else { |
| 905 | return new MBeanOperationInfo(oi.getName(), |
| 906 | description, |
| 907 | signature, |
| 908 | oi.getReturnType(), |
| 909 | impact, |
| 910 | oi.getDescriptor()); |
| 911 | } |
| 912 | } |
| 913 | |
| 914 | private static MBeanAttributeInfo |
| 915 | customize(MBeanAttributeInfo ai, |
| 916 | String description) { |
| 917 | if (equal(description, ai.getDescription())) |
| 918 | return ai; |
| 919 | if (ai instanceof OpenMBeanAttributeInfo) { |
| 920 | OpenMBeanAttributeInfo oai = (OpenMBeanAttributeInfo) ai; |
| 921 | return new OpenMBeanAttributeInfoSupport(ai.getName(), |
| 922 | description, |
| 923 | oai.getOpenType(), |
| 924 | ai.isReadable(), |
| 925 | ai.isWritable(), |
| 926 | ai.isIs(), |
| 927 | ai.getDescriptor()); |
| 928 | } else { |
| 929 | return new MBeanAttributeInfo(ai.getName(), |
| 930 | ai.getType(), |
| 931 | description, |
| 932 | ai.isReadable(), |
| 933 | ai.isWritable(), |
| 934 | ai.isIs(), |
| 935 | ai.getDescriptor()); |
| 936 | } |
| 937 | } |
| 938 | |
| 939 | private static OpenMBeanParameterInfo[] |
| 940 | paramsToOpenParams(MBeanParameterInfo[] params) { |
| 941 | if (params instanceof OpenMBeanParameterInfo[]) |
| 942 | return (OpenMBeanParameterInfo[]) params; |
| 943 | OpenMBeanParameterInfo[] oparams = |
| 944 | new OpenMBeanParameterInfoSupport[params.length]; |
| 945 | System.arraycopy(params, 0, oparams, 0, params.length); |
| 946 | return oparams; |
| 947 | } |
| 948 | |
| 949 | // ------------------------------------------------------------------ |
| 950 | // Build the custom MBeanConstructorInfo[] |
| 951 | // ------------------------------------------------------------------ |
| 952 | private MBeanConstructorInfo[] |
| 953 | getConstructors(MBeanInfo info, Object impl) { |
| 954 | final MBeanConstructorInfo[] ctors = |
| 955 | getConstructors(info.getConstructors(), impl); |
| 956 | if (ctors == null) |
| 957 | return null; |
| 958 | final int ctorlen = ctors.length; |
| 959 | final MBeanConstructorInfo[] nctors = new MBeanConstructorInfo[ctorlen]; |
| 960 | for (int i=0; i<ctorlen; i++) { |
| 961 | final MBeanConstructorInfo c = ctors[i]; |
| 962 | final MBeanParameterInfo[] params = c.getSignature(); |
| 963 | final MBeanParameterInfo[] nps; |
| 964 | if (params != null) { |
| 965 | final int plen = params.length; |
| 966 | nps = new MBeanParameterInfo[plen]; |
| 967 | for (int ii=0;ii<plen;ii++) { |
| 968 | MBeanParameterInfo p = params[ii]; |
| 969 | nps[ii] = customize(p, |
| 970 | getParameterName(c,p,ii), |
| 971 | getDescription(c,p,ii)); |
| 972 | } |
| 973 | } else { |
| 974 | nps = null; |
| 975 | } |
| 976 | nctors[i] = |
| 977 | customize(c, getDescription(c), nps); |
| 978 | } |
| 979 | return nctors; |
| 980 | } |
| 981 | |
| 982 | // ------------------------------------------------------------------ |
| 983 | // Build the custom MBeanOperationInfo[] |
| 984 | // ------------------------------------------------------------------ |
| 985 | private MBeanOperationInfo[] getOperations(MBeanInfo info) { |
| 986 | final MBeanOperationInfo[] ops = info.getOperations(); |
| 987 | if (ops == null) |
| 988 | return null; |
| 989 | final int oplen = ops.length; |
| 990 | final MBeanOperationInfo[] nops = new MBeanOperationInfo[oplen]; |
| 991 | for (int i=0; i<oplen; i++) { |
| 992 | final MBeanOperationInfo o = ops[i]; |
| 993 | final MBeanParameterInfo[] params = o.getSignature(); |
| 994 | final MBeanParameterInfo[] nps; |
| 995 | if (params != null) { |
| 996 | final int plen = params.length; |
| 997 | nps = new MBeanParameterInfo[plen]; |
| 998 | for (int ii=0;ii<plen;ii++) { |
| 999 | MBeanParameterInfo p = params[ii]; |
| 1000 | nps[ii] = customize(p, |
| 1001 | getParameterName(o,p,ii), |
| 1002 | getDescription(o,p,ii)); |
| 1003 | } |
| 1004 | } else { |
| 1005 | nps = null; |
| 1006 | } |
| 1007 | nops[i] = customize(o, getDescription(o), nps, getImpact(o)); |
| 1008 | } |
| 1009 | return nops; |
| 1010 | } |
| 1011 | |
| 1012 | // ------------------------------------------------------------------ |
| 1013 | // Build the custom MBeanAttributeInfo[] |
| 1014 | // ------------------------------------------------------------------ |
| 1015 | private MBeanAttributeInfo[] getAttributes(MBeanInfo info) { |
| 1016 | final MBeanAttributeInfo[] atts = info.getAttributes(); |
| 1017 | if (atts == null) |
| 1018 | return null; // should not happen |
| 1019 | final MBeanAttributeInfo[] natts; |
| 1020 | final int attlen = atts.length; |
| 1021 | natts = new MBeanAttributeInfo[attlen]; |
| 1022 | for (int i=0; i<attlen; i++) { |
| 1023 | final MBeanAttributeInfo a = atts[i]; |
| 1024 | natts[i] = customize(a, getDescription(a)); |
| 1025 | } |
| 1026 | return natts; |
| 1027 | } |
| 1028 | |
| 1029 | /** |
| 1030 | * <p>Allows the MBean to perform any operations it needs before |
| 1031 | * being registered in the MBean server. If the name of the MBean |
| 1032 | * is not specified, the MBean can provide a name for its |
| 1033 | * registration. If any exception is raised, the MBean will not be |
| 1034 | * registered in the MBean server.</p> |
| 1035 | * |
| 1036 | * <p>The default implementation of this method returns the {@code name} |
| 1037 | * parameter. It does nothing else for |
| 1038 | * Standard MBeans. For MXBeans, it records the {@code MBeanServer} |
| 1039 | * and {@code ObjectName} parameters so they can be used to translate |
| 1040 | * inter-MXBean references.</p> |
| 1041 | * |
| 1042 | * <p>It is good practice for a subclass that overrides this method |
| 1043 | * to call the overridden method via {@code super.preRegister(...)}. |
| 1044 | * This is necessary if this object is an MXBean that is referenced |
| 1045 | * by attributes or operations in other MXBeans.</p> |
| 1046 | * |
| 1047 | * @param server The MBean server in which the MBean will be registered. |
| 1048 | * |
| 1049 | * @param name The object name of the MBean. This name is null if |
| 1050 | * the name parameter to one of the <code>createMBean</code> or |
| 1051 | * <code>registerMBean</code> methods in the {@link MBeanServer} |
| 1052 | * interface is null. In that case, this method must return a |
| 1053 | * non-null ObjectName for the new MBean. |
| 1054 | * |
| 1055 | * @return The name under which the MBean is to be registered. |
| 1056 | * This value must not be null. If the <code>name</code> |
| 1057 | * parameter is not null, it will usually but not necessarily be |
| 1058 | * the returned value. |
| 1059 | * |
| 1060 | * @throws IllegalArgumentException if this is an MXBean and |
| 1061 | * {@code name} is null. |
| 1062 | * |
| 1063 | * @throws InstanceAlreadyExistsException if this is an MXBean and |
| 1064 | * it has already been registered under another name (in this |
| 1065 | * MBean Server or another). |
| 1066 | * |
| 1067 | * @throws Exception no other checked exceptions are thrown by |
| 1068 | * this method but {@code Exception} is declared so that subclasses |
| 1069 | * can override the method and throw their own exceptions. |
| 1070 | * |
| 1071 | * @since 1.6 |
| 1072 | */ |
| 1073 | public ObjectName preRegister(MBeanServer server, ObjectName name) |
| 1074 | throws Exception { |
| 1075 | mbean.register(server, name); |
| 1076 | return name; |
| 1077 | } |
| 1078 | |
| 1079 | /** |
| 1080 | * <p>Allows the MBean to perform any operations needed after having been |
| 1081 | * registered in the MBean server or after the registration has failed.</p> |
| 1082 | * |
| 1083 | * <p>The default implementation of this method does nothing for |
| 1084 | * Standard MBeans. For MXBeans, it undoes any work done by |
| 1085 | * {@link #preRegister preRegister} if registration fails.</p> |
| 1086 | * |
| 1087 | * <p>It is good practice for a subclass that overrides this method |
| 1088 | * to call the overridden method via {@code super.postRegister(...)}. |
| 1089 | * This is necessary if this object is an MXBean that is referenced |
| 1090 | * by attributes or operations in other MXBeans.</p> |
| 1091 | * |
| 1092 | * @param registrationDone Indicates whether or not the MBean has |
| 1093 | * been successfully registered in the MBean server. The value |
| 1094 | * false means that the registration phase has failed. |
| 1095 | * |
| 1096 | * @since 1.6 |
| 1097 | */ |
| 1098 | public void postRegister(Boolean registrationDone) { |
| 1099 | if (!registrationDone) |
| 1100 | mbean.unregister(); |
| 1101 | } |
| 1102 | |
| 1103 | /** |
| 1104 | * <p>Allows the MBean to perform any operations it needs before |
| 1105 | * being unregistered by the MBean server.</p> |
| 1106 | * |
| 1107 | * <p>The default implementation of this method does nothing.</p> |
| 1108 | * |
| 1109 | * <p>It is good practice for a subclass that overrides this method |
| 1110 | * to call the overridden method via {@code super.preDeegister(...)}.</p> |
| 1111 | * |
| 1112 | * @throws Exception no checked exceptions are throw by this method |
| 1113 | * but {@code Exception} is declared so that subclasses can override |
| 1114 | * this method and throw their own exceptions. |
| 1115 | * |
| 1116 | * @since 1.6 |
| 1117 | */ |
| 1118 | public void preDeregister() throws Exception { |
| 1119 | } |
| 1120 | |
| 1121 | /** |
| 1122 | * <p>Allows the MBean to perform any operations needed after having been |
| 1123 | * unregistered in the MBean server.</p> |
| 1124 | * |
| 1125 | * <p>The default implementation of this method does nothing for |
| 1126 | * Standard MBeans. For MXBeans, it removes any information that |
| 1127 | * was recorded by the {@link #preRegister preRegister} method.</p> |
| 1128 | * |
| 1129 | * <p>It is good practice for a subclass that overrides this method |
| 1130 | * to call the overridden method via {@code super.postRegister(...)}. |
| 1131 | * This is necessary if this object is an MXBean that is referenced |
| 1132 | * by attributes or operations in other MXBeans.</p> |
| 1133 | * |
| 1134 | * @since 1.6 |
| 1135 | */ |
| 1136 | public void postDeregister() { |
| 1137 | mbean.unregister(); |
| 1138 | } |
| 1139 | |
| 1140 | // |
| 1141 | // MBeanInfo immutability |
| 1142 | // |
| 1143 | |
| 1144 | /** |
| 1145 | * Cached results of previous calls to immutableInfo. This is |
| 1146 | * a WeakHashMap so that we don't prevent a class from being |
| 1147 | * garbage collected just because we know whether its MBeanInfo |
| 1148 | * is immutable. |
| 1149 | */ |
| 1150 | private static final Map<Class, Boolean> mbeanInfoSafeMap = |
| 1151 | new WeakHashMap<Class, Boolean>(); |
| 1152 | |
| 1153 | /** |
| 1154 | * Return true if {@code subclass} is known to preserve the immutability |
| 1155 | * of the {@code MBeanInfo}. The {@code subclass} is considered to have |
| 1156 | * an immutable {@code MBeanInfo} if it does not override any of the |
| 1157 | * getMBeanInfo, getCachedMBeanInfo, cacheMBeanInfo and getNotificationInfo |
| 1158 | * methods. |
| 1159 | */ |
| 1160 | static boolean immutableInfo(Class<? extends StandardMBean> subclass) { |
| 1161 | if (subclass == StandardMBean.class || |
| 1162 | subclass == StandardEmitterMBean.class) |
| 1163 | return true; |
| 1164 | synchronized (mbeanInfoSafeMap) { |
| 1165 | Boolean safe = mbeanInfoSafeMap.get(subclass); |
| 1166 | if (safe == null) { |
| 1167 | try { |
| 1168 | MBeanInfoSafeAction action = |
| 1169 | new MBeanInfoSafeAction(subclass); |
| 1170 | safe = AccessController.doPrivileged(action); |
| 1171 | } catch (Exception e) { // e.g. SecurityException |
| 1172 | /* We don't know, so we assume it isn't. */ |
| 1173 | safe = false; |
| 1174 | } |
| 1175 | mbeanInfoSafeMap.put(subclass, safe); |
| 1176 | } |
| 1177 | return safe; |
| 1178 | } |
| 1179 | } |
| 1180 | |
| 1181 | static boolean overrides(Class<?> subclass, Class<?> superclass, |
| 1182 | String name, Class<?>... params) { |
| 1183 | for (Class<?> c = subclass; c != superclass; c = c.getSuperclass()) { |
| 1184 | try { |
| 1185 | c.getDeclaredMethod(name, params); |
| 1186 | return true; |
| 1187 | } catch (NoSuchMethodException e) { |
| 1188 | // OK: this class doesn't override it |
| 1189 | } |
| 1190 | } |
| 1191 | return false; |
| 1192 | } |
| 1193 | |
| 1194 | private static class MBeanInfoSafeAction |
| 1195 | implements PrivilegedAction<Boolean> { |
| 1196 | |
| 1197 | private final Class subclass; |
| 1198 | |
| 1199 | MBeanInfoSafeAction(Class subclass) { |
| 1200 | this.subclass = subclass; |
| 1201 | } |
| 1202 | |
| 1203 | public Boolean run() { |
| 1204 | // Check for "void cacheMBeanInfo(MBeanInfo)" method. |
| 1205 | // |
| 1206 | if (overrides(subclass, StandardMBean.class, |
| 1207 | "cacheMBeanInfo", MBeanInfo.class)) |
| 1208 | return false; |
| 1209 | |
| 1210 | // Check for "MBeanInfo getCachedMBeanInfo()" method. |
| 1211 | // |
| 1212 | if (overrides(subclass, StandardMBean.class, |
| 1213 | "getCachedMBeanInfo", (Class[]) null)) |
| 1214 | return false; |
| 1215 | |
| 1216 | // Check for "MBeanInfo getMBeanInfo()" method. |
| 1217 | // |
| 1218 | if (overrides(subclass, StandardMBean.class, |
| 1219 | "getMBeanInfo", (Class[]) null)) |
| 1220 | return false; |
| 1221 | |
| 1222 | // Check for "MBeanNotificationInfo[] getNotificationInfo()" |
| 1223 | // method. |
| 1224 | // |
| 1225 | // This method is only taken into account for the MBeanInfo |
| 1226 | // immutability checks if and only if the given subclass is |
| 1227 | // StandardEmitterMBean itself or can be assigned to |
| 1228 | // StandardEmitterMBean. |
| 1229 | // |
| 1230 | if (StandardEmitterMBean.class.isAssignableFrom(subclass)) |
| 1231 | if (overrides(subclass, StandardEmitterMBean.class, |
| 1232 | "getNotificationInfo", (Class[]) null)) |
| 1233 | return false; |
| 1234 | return true; |
| 1235 | } |
| 1236 | } |
| 1237 | |
| 1238 | } |