J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 1999-2006 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 java.lang.reflect.Method; |
| 29 | import java.security.AccessController; |
| 30 | |
| 31 | import com.sun.jmx.mbeanserver.GetPropertyAction; |
| 32 | import com.sun.jmx.mbeanserver.Introspector; |
| 33 | |
| 34 | |
| 35 | /** |
| 36 | * Describes an MBean attribute exposed for management. Instances of |
| 37 | * this class are immutable. Subclasses may be mutable but this is |
| 38 | * not recommended. |
| 39 | * |
| 40 | * @since 1.5 |
| 41 | */ |
| 42 | @SuppressWarnings("serial") // serialVersionUID not constant |
| 43 | public class MBeanAttributeInfo extends MBeanFeatureInfo implements Cloneable { |
| 44 | |
| 45 | /* Serial version */ |
| 46 | private static final long serialVersionUID; |
| 47 | static { |
| 48 | /* For complicated reasons, the serialVersionUID changed |
| 49 | between JMX 1.0 and JMX 1.1, even though JMX 1.1 did not |
| 50 | have compatibility code for this class. So the |
| 51 | serialization produced by this class with JMX 1.2 and |
| 52 | jmx.serial.form=1.0 is not the same as that produced by |
| 53 | this class with JMX 1.1 and jmx.serial.form=1.0. However, |
| 54 | the serialization without that property is the same, and |
| 55 | that is the only form required by JMX 1.2. |
| 56 | */ |
| 57 | long uid = 8644704819898565848L; |
| 58 | try { |
| 59 | GetPropertyAction act = new GetPropertyAction("jmx.serial.form"); |
| 60 | String form = AccessController.doPrivileged(act); |
| 61 | if ("1.0".equals(form)) |
| 62 | uid = 7043855487133450673L; |
| 63 | } catch (Exception e) { |
| 64 | // OK: exception means no compat with 1.0, too bad |
| 65 | } |
| 66 | serialVersionUID = uid; |
| 67 | } |
| 68 | |
| 69 | static final MBeanAttributeInfo[] NO_ATTRIBUTES = |
| 70 | new MBeanAttributeInfo[0]; |
| 71 | |
| 72 | /** |
| 73 | * @serial The actual attribute type. |
| 74 | */ |
| 75 | private final String attributeType; |
| 76 | |
| 77 | /** |
| 78 | * @serial The attribute write right. |
| 79 | */ |
| 80 | private final boolean isWrite; |
| 81 | |
| 82 | /** |
| 83 | * @serial The attribute read right. |
| 84 | */ |
| 85 | private final boolean isRead; |
| 86 | |
| 87 | /** |
| 88 | * @serial Indicates if this method is a "is" |
| 89 | */ |
| 90 | private final boolean is; |
| 91 | |
| 92 | |
| 93 | /** |
| 94 | * Constructs an <CODE>MBeanAttributeInfo</CODE> object. |
| 95 | * |
| 96 | * @param name The name of the attribute. |
| 97 | * @param type The type or class name of the attribute. |
| 98 | * @param description A human readable description of the attribute. |
| 99 | * @param isReadable True if the attribute has a getter method, false otherwise. |
| 100 | * @param isWritable True if the attribute has a setter method, false otherwise. |
| 101 | * @param isIs True if this attribute has an "is" getter, false otherwise. |
| 102 | * |
| 103 | * @throws IllegalArgumentException if {@code isIs} is true but |
| 104 | * {@code isReadable} is not, or if {@code isIs} is true and |
| 105 | * {@code type} is not {@code boolean} or {@code java.lang.Boolean}. |
| 106 | * (New code should always use {@code boolean} rather than |
| 107 | * {@code java.lang.Boolean}.) |
| 108 | */ |
| 109 | public MBeanAttributeInfo(String name, |
| 110 | String type, |
| 111 | String description, |
| 112 | boolean isReadable, |
| 113 | boolean isWritable, |
| 114 | boolean isIs) { |
| 115 | this(name, type, description, isReadable, isWritable, isIs, |
| 116 | (Descriptor) null); |
| 117 | } |
| 118 | |
| 119 | /** |
| 120 | * Constructs an <CODE>MBeanAttributeInfo</CODE> object. |
| 121 | * |
| 122 | * @param name The name of the attribute. |
| 123 | * @param type The type or class name of the attribute. |
| 124 | * @param description A human readable description of the attribute. |
| 125 | * @param isReadable True if the attribute has a getter method, false otherwise. |
| 126 | * @param isWritable True if the attribute has a setter method, false otherwise. |
| 127 | * @param isIs True if this attribute has an "is" getter, false otherwise. |
| 128 | * @param descriptor The descriptor for the attribute. This may be null |
| 129 | * which is equivalent to an empty descriptor. |
| 130 | * |
| 131 | * @throws IllegalArgumentException if {@code isIs} is true but |
| 132 | * {@code isReadable} is not, or if {@code isIs} is true and |
| 133 | * {@code type} is not {@code boolean} or {@code java.lang.Boolean}. |
| 134 | * (New code should always use {@code boolean} rather than |
| 135 | * {@code java.lang.Boolean}.) |
| 136 | * |
| 137 | * @since 1.6 |
| 138 | */ |
| 139 | public MBeanAttributeInfo(String name, |
| 140 | String type, |
| 141 | String description, |
| 142 | boolean isReadable, |
| 143 | boolean isWritable, |
| 144 | boolean isIs, |
| 145 | Descriptor descriptor) { |
| 146 | super(name, description, descriptor); |
| 147 | |
| 148 | this.attributeType = type; |
| 149 | this.isRead = isReadable; |
| 150 | this.isWrite = isWritable; |
| 151 | if (isIs && !isReadable) { |
| 152 | throw new IllegalArgumentException("Cannot have an \"is\" getter " + |
| 153 | "for a non-readable attribute"); |
| 154 | } |
| 155 | if (isIs && !type.equals("java.lang.Boolean") && |
| 156 | !type.equals("boolean")) { |
| 157 | throw new IllegalArgumentException("Cannot have an \"is\" getter " + |
| 158 | "for a non-boolean attribute"); |
| 159 | } |
| 160 | this.is = isIs; |
| 161 | } |
| 162 | |
| 163 | /** |
| 164 | * <p>This constructor takes the name of a simple attribute, and Method |
| 165 | * objects for reading and writing the attribute. The {@link Descriptor} |
| 166 | * of the constructed object will include fields contributed by any |
| 167 | * annotations on the {@code Method} objects that contain the |
| 168 | * {@link DescriptorKey} meta-annotation. |
| 169 | * |
| 170 | * @param name The programmatic name of the attribute. |
| 171 | * @param description A human readable description of the attribute. |
| 172 | * @param getter The method used for reading the attribute value. |
| 173 | * May be null if the property is write-only. |
| 174 | * @param setter The method used for writing the attribute value. |
| 175 | * May be null if the attribute is read-only. |
| 176 | * @exception IntrospectionException There is a consistency |
| 177 | * problem in the definition of this attribute. |
| 178 | */ |
| 179 | public MBeanAttributeInfo(String name, |
| 180 | String description, |
| 181 | Method getter, |
| 182 | Method setter) throws IntrospectionException { |
| 183 | this(name, |
| 184 | attributeType(getter, setter), |
| 185 | description, |
| 186 | (getter != null), |
| 187 | (setter != null), |
| 188 | isIs(getter), |
| 189 | ImmutableDescriptor.union(Introspector.descriptorForElement(getter), |
| 190 | Introspector.descriptorForElement(setter))); |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * <p>Returns a shallow clone of this instance. |
| 195 | * The clone is obtained by simply calling <tt>super.clone()</tt>, |
| 196 | * thus calling the default native shallow cloning mechanism |
| 197 | * implemented by <tt>Object.clone()</tt>. |
| 198 | * No deeper cloning of any internal field is made.</p> |
| 199 | * |
| 200 | * <p>Since this class is immutable, cloning is chiefly of |
| 201 | * interest to subclasses.</p> |
| 202 | */ |
| 203 | public Object clone () { |
| 204 | try { |
| 205 | return super.clone() ; |
| 206 | } catch (CloneNotSupportedException e) { |
| 207 | // should not happen as this class is cloneable |
| 208 | return null; |
| 209 | } |
| 210 | } |
| 211 | |
| 212 | /** |
| 213 | * Returns the class name of the attribute. |
| 214 | * |
| 215 | * @return the class name. |
| 216 | */ |
| 217 | public String getType() { |
| 218 | return attributeType; |
| 219 | } |
| 220 | |
| 221 | /** |
| 222 | * Whether the value of the attribute can be read. |
| 223 | * |
| 224 | * @return True if the attribute can be read, false otherwise. |
| 225 | */ |
| 226 | public boolean isReadable() { |
| 227 | return isRead; |
| 228 | } |
| 229 | |
| 230 | /** |
| 231 | * Whether new values can be written to the attribute. |
| 232 | * |
| 233 | * @return True if the attribute can be written to, false otherwise. |
| 234 | */ |
| 235 | public boolean isWritable() { |
| 236 | return isWrite; |
| 237 | } |
| 238 | |
| 239 | /** |
| 240 | * Indicates if this attribute has an "is" getter. |
| 241 | * |
| 242 | * @return true if this attribute has an "is" getter. |
| 243 | */ |
| 244 | public boolean isIs() { |
| 245 | return is; |
| 246 | } |
| 247 | |
| 248 | public String toString() { |
| 249 | String access; |
| 250 | if (isReadable()) { |
| 251 | if (isWritable()) |
| 252 | access = "read/write"; |
| 253 | else |
| 254 | access = "read-only"; |
| 255 | } else if (isWritable()) |
| 256 | access = "write-only"; |
| 257 | else |
| 258 | access = "no-access"; |
| 259 | |
| 260 | return |
| 261 | getClass().getName() + "[" + |
| 262 | "description=" + getDescription() + ", " + |
| 263 | "name=" + getName() + ", " + |
| 264 | "type=" + getType() + ", " + |
| 265 | access + ", " + |
| 266 | (isIs() ? "isIs, " : "") + |
| 267 | "descriptor=" + getDescriptor() + |
| 268 | "]"; |
| 269 | } |
| 270 | |
| 271 | /** |
| 272 | * Compare this MBeanAttributeInfo to another. |
| 273 | * |
| 274 | * @param o the object to compare to. |
| 275 | * |
| 276 | * @return true if and only if <code>o</code> is an MBeanAttributeInfo such |
| 277 | * that its {@link #getName()}, {@link #getType()}, {@link |
| 278 | * #getDescription()}, {@link #isReadable()}, {@link |
| 279 | * #isWritable()}, and {@link #isIs()} values are equal (not |
| 280 | * necessarily identical) to those of this MBeanAttributeInfo. |
| 281 | */ |
| 282 | public boolean equals(Object o) { |
| 283 | if (o == this) |
| 284 | return true; |
| 285 | if (!(o instanceof MBeanAttributeInfo)) |
| 286 | return false; |
| 287 | MBeanAttributeInfo p = (MBeanAttributeInfo) o; |
| 288 | return (p.getName().equals(getName()) && |
| 289 | p.getType().equals(getType()) && |
| 290 | p.getDescription().equals(getDescription()) && |
| 291 | p.getDescriptor().equals(getDescriptor()) && |
| 292 | p.isReadable() == isReadable() && |
| 293 | p.isWritable() == isWritable() && |
| 294 | p.isIs() == isIs()); |
| 295 | } |
| 296 | |
| 297 | /* We do not include everything in the hashcode. We assume that |
| 298 | if two operations are different they'll probably have different |
| 299 | names or types. The penalty we pay when this assumption is |
| 300 | wrong should be less than the penalty we would pay if it were |
| 301 | right and we needlessly hashed in the description and parameter |
| 302 | array. */ |
| 303 | public int hashCode() { |
| 304 | return getName().hashCode() ^ getType().hashCode(); |
| 305 | } |
| 306 | |
| 307 | private static boolean isIs(Method getter) { |
| 308 | return (getter != null && |
| 309 | getter.getName().startsWith("is") && |
| 310 | (getter.getReturnType().equals(Boolean.TYPE) || |
| 311 | getter.getReturnType().equals(Boolean.class))); |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * Finds the type of the attribute. |
| 316 | */ |
| 317 | private static String attributeType(Method getter, Method setter) |
| 318 | throws IntrospectionException { |
| 319 | Class type = null; |
| 320 | |
| 321 | if (getter != null) { |
| 322 | if (getter.getParameterTypes().length != 0) { |
| 323 | throw new IntrospectionException("bad getter arg count"); |
| 324 | } |
| 325 | type = getter.getReturnType(); |
| 326 | if (type == Void.TYPE) { |
| 327 | throw new IntrospectionException("getter " + getter.getName() + |
| 328 | " returns void"); |
| 329 | } |
| 330 | } |
| 331 | |
| 332 | if (setter != null) { |
| 333 | Class params[] = setter.getParameterTypes(); |
| 334 | if (params.length != 1) { |
| 335 | throw new IntrospectionException("bad setter arg count"); |
| 336 | } |
| 337 | if (type == null) |
| 338 | type = params[0]; |
| 339 | else if (type != params[0]) { |
| 340 | throw new IntrospectionException("type mismatch between " + |
| 341 | "getter and setter"); |
| 342 | } |
| 343 | } |
| 344 | |
| 345 | if (type == null) { |
| 346 | throw new IntrospectionException("getter and setter cannot " + |
| 347 | "both be null"); |
| 348 | } |
| 349 | |
| 350 | return type.getName(); |
| 351 | } |
| 352 | |
| 353 | } |