J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2006 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 com.sun.jmx.mbeanserver; |
| 27 | |
| 28 | import static com.sun.jmx.mbeanserver.Util.*; |
| 29 | |
| 30 | import java.lang.reflect.Method; |
| 31 | import java.util.Arrays; |
| 32 | import java.util.Collection; |
| 33 | import java.util.Comparator; |
| 34 | import java.util.HashSet; |
| 35 | import java.util.List; |
| 36 | import java.util.Map; |
| 37 | import java.util.Set; |
| 38 | |
| 39 | import javax.management.NotCompliantMBeanException; |
| 40 | |
| 41 | /** |
| 42 | * <p>An analyzer for a given MBean interface. The analyzer can |
| 43 | * be for Standard MBeans or MXBeans, depending on the MBeanIntrospector |
| 44 | * passed at construction. |
| 45 | * |
| 46 | * <p>The analyzer can |
| 47 | * visit the attributes and operations of the interface, calling |
| 48 | * a caller-supplied visitor method for each one.</p> |
| 49 | * |
| 50 | * @param <M> Method or ConvertingMethod according as this is a |
| 51 | * Standard MBean or an MXBean. |
| 52 | * |
| 53 | * @since 1.6 |
| 54 | */ |
| 55 | class MBeanAnalyzer<M> { |
| 56 | |
| 57 | static interface MBeanVisitor<M> { |
| 58 | public void visitAttribute(String attributeName, |
| 59 | M getter, |
| 60 | M setter); |
| 61 | public void visitOperation(String operationName, |
| 62 | M operation); |
| 63 | } |
| 64 | |
| 65 | void visit(MBeanVisitor<M> visitor) { |
| 66 | // visit attributes |
| 67 | for (Map.Entry<String, AttrMethods<M>> entry : attrMap.entrySet()) { |
| 68 | String name = entry.getKey(); |
| 69 | AttrMethods<M> am = entry.getValue(); |
| 70 | visitor.visitAttribute(name, am.getter, am.setter); |
| 71 | } |
| 72 | |
| 73 | // visit operations |
| 74 | for (Map.Entry<String, List<M>> entry : opMap.entrySet()) { |
| 75 | for (M m : entry.getValue()) |
| 76 | visitor.visitOperation(entry.getKey(), m); |
| 77 | } |
| 78 | } |
| 79 | |
| 80 | /* Map op name to method */ |
| 81 | private Map<String, List<M>> opMap = newInsertionOrderMap(); |
| 82 | /* Map attr name to getter and/or setter */ |
| 83 | private Map<String, AttrMethods<M>> attrMap = newInsertionOrderMap(); |
| 84 | |
| 85 | private static class AttrMethods<M> { |
| 86 | M getter; |
| 87 | M setter; |
| 88 | } |
| 89 | |
| 90 | /** |
| 91 | * <p>Return an MBeanAnalyzer for the given MBean interface and |
| 92 | * MBeanIntrospector. Calling this method twice with the same |
| 93 | * parameters may return the same object or two different but |
| 94 | * equivalent objects. |
| 95 | */ |
| 96 | // Currently it's two different but equivalent objects. This only |
| 97 | // really impacts proxy generation. For MBean creation, the |
| 98 | // cached PerInterface object for an MBean interface means that |
| 99 | // an analyzer will not be recreated for a second MBean using the |
| 100 | // same interface. |
| 101 | static <M> MBeanAnalyzer<M> analyzer(Class<?> mbeanInterface, |
| 102 | MBeanIntrospector<M> introspector) |
| 103 | throws NotCompliantMBeanException { |
| 104 | return new MBeanAnalyzer<M>(mbeanInterface, introspector); |
| 105 | } |
| 106 | |
| 107 | private MBeanAnalyzer(Class<?> mbeanInterface, |
| 108 | MBeanIntrospector<M> introspector) |
| 109 | throws NotCompliantMBeanException { |
| 110 | if (!mbeanInterface.isInterface()) { |
| 111 | throw new NotCompliantMBeanException("Not an interface: " + |
| 112 | mbeanInterface.getName()); |
| 113 | } |
| 114 | |
| 115 | try { |
| 116 | initMaps(mbeanInterface, introspector); |
| 117 | } catch (Exception x) { |
| 118 | throw Introspector.throwException(mbeanInterface,x); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | // Introspect the mbeanInterface and initialize this object's maps. |
| 123 | // |
| 124 | private void initMaps(Class<?> mbeanInterface, |
| 125 | MBeanIntrospector<M> introspector) throws Exception { |
| 126 | final Method[] methodArray = mbeanInterface.getMethods(); |
| 127 | |
| 128 | final List<Method> methods = eliminateCovariantMethods(methodArray); |
| 129 | |
| 130 | /* Run through the methods to detect inconsistencies and to enable |
| 131 | us to give getter and setter together to visitAttribute. */ |
| 132 | for (Method m : methods) { |
| 133 | String name = m.getName(); |
| 134 | |
| 135 | final M cm = introspector.mFrom(m); |
| 136 | |
| 137 | String attrName = ""; |
| 138 | if (name.startsWith("get")) |
| 139 | attrName = name.substring(3); |
| 140 | else if (name.startsWith("is") |
| 141 | && m.getReturnType() == boolean.class) |
| 142 | attrName = name.substring(2); |
| 143 | |
| 144 | if (attrName.length() != 0 && m.getParameterTypes().length == 0 |
| 145 | && m.getReturnType() != void.class) { |
| 146 | // It's a getter |
| 147 | // Check we don't have both isX and getX |
| 148 | AttrMethods<M> am = attrMap.get(attrName); |
| 149 | if (am == null) |
| 150 | am = new AttrMethods<M>(); |
| 151 | else { |
| 152 | if (am.getter != null) { |
| 153 | final String msg = "Attribute " + attrName + |
| 154 | " has more than one getter"; |
| 155 | throw new NotCompliantMBeanException(msg); |
| 156 | } |
| 157 | } |
| 158 | am.getter = cm; |
| 159 | attrMap.put(attrName, am); |
| 160 | } else if (name.startsWith("set") && name.length() > 3 |
| 161 | && m.getParameterTypes().length == 1 && |
| 162 | m.getReturnType() == void.class) { |
| 163 | // It's a setter |
| 164 | attrName = name.substring(3); |
| 165 | AttrMethods<M> am = attrMap.get(attrName); |
| 166 | if (am == null) |
| 167 | am = new AttrMethods<M>(); |
| 168 | else if (am.setter != null) { |
| 169 | final String msg = "Attribute " + attrName + |
| 170 | " has more than one setter"; |
| 171 | throw new NotCompliantMBeanException(msg); |
| 172 | } |
| 173 | am.setter = cm; |
| 174 | attrMap.put(attrName, am); |
| 175 | } else { |
| 176 | // It's an operation |
| 177 | List<M> cms = opMap.get(name); |
| 178 | if (cms == null) |
| 179 | cms = newList(); |
| 180 | cms.add(cm); |
| 181 | opMap.put(name, cms); |
| 182 | } |
| 183 | } |
| 184 | /* Check that getters and setters are consistent. */ |
| 185 | for (Map.Entry<String, AttrMethods<M>> entry : attrMap.entrySet()) { |
| 186 | AttrMethods<M> am = entry.getValue(); |
| 187 | if (!introspector.consistent(am.getter, am.setter)) { |
| 188 | final String msg = "Getter and setter for " + entry.getKey() + |
| 189 | " have inconsistent types"; |
| 190 | throw new NotCompliantMBeanException(msg); |
| 191 | } |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | /** |
| 196 | * A comparator that defines a total order so that methods have the |
| 197 | * same name and identical signatures appear next to each others. |
| 198 | * The methods are sorted in such a way that methods which |
| 199 | * override each other will sit next to each other, with the |
| 200 | * overridden method first - e.g. Object getFoo() is placed before |
| 201 | * Integer getFoo(). This makes it possible to determine whether |
| 202 | * a method overrides another one simply by looking at the method(s) |
| 203 | * that precedes it in the list. (see eliminateCovariantMethods). |
| 204 | **/ |
| 205 | private static class MethodOrder implements Comparator<Method> { |
| 206 | public int compare(Method a, Method b) { |
| 207 | final int cmp = a.getName().compareTo(b.getName()); |
| 208 | if (cmp != 0) return cmp; |
| 209 | final Class<?>[] aparams = a.getParameterTypes(); |
| 210 | final Class<?>[] bparams = b.getParameterTypes(); |
| 211 | if (aparams.length != bparams.length) |
| 212 | return aparams.length - bparams.length; |
| 213 | if (!Arrays.equals(aparams, bparams)) { |
| 214 | return Arrays.toString(aparams). |
| 215 | compareTo(Arrays.toString(bparams)); |
| 216 | } |
| 217 | final Class<?> aret = a.getReturnType(); |
| 218 | final Class<?> bret = b.getReturnType(); |
| 219 | if (aret == bret) return 0; |
| 220 | |
| 221 | // Super type comes first: Object, Number, Integer |
| 222 | if (aret.isAssignableFrom(bret)) |
| 223 | return -1; |
| 224 | return +1; // could assert bret.isAssignableFrom(aret) |
| 225 | } |
| 226 | public final static MethodOrder instance = new MethodOrder(); |
| 227 | } |
| 228 | |
| 229 | |
| 230 | /* Eliminate methods that are overridden with a covariant return type. |
| 231 | Reflection will return both the original and the overriding method |
| 232 | but only the overriding one is of interest. We return the methods |
| 233 | in the same order they arrived in. This isn't required by the spec |
| 234 | but existing code may depend on it and users may be used to seeing |
| 235 | operations or attributes appear in a particular order. */ |
| 236 | static List<Method> |
| 237 | eliminateCovariantMethods(Method[] methodArray) { |
| 238 | // We are assuming that you never have very many methods with the |
| 239 | // same name, so it is OK to use algorithms that are quadratic |
| 240 | // in the number of methods with the same name. |
| 241 | |
| 242 | final int len = methodArray.length; |
| 243 | final Method[] sorted = methodArray.clone(); |
| 244 | Arrays.sort(sorted,MethodOrder.instance); |
| 245 | final Set<Method> overridden = newSet(); |
| 246 | for (int i=1;i<len;i++) { |
| 247 | final Method m0 = sorted[i-1]; |
| 248 | final Method m1 = sorted[i]; |
| 249 | |
| 250 | // Methods that don't have the same name can't override each others |
| 251 | if (!m0.getName().equals(m1.getName())) continue; |
| 252 | |
| 253 | // Methods that have the same name and same signature override |
| 254 | // each other. In that case, the second method overrides the first, |
| 255 | // due to the way we have sorted them in MethodOrder. |
| 256 | if (Arrays.equals(m0.getParameterTypes(), |
| 257 | m1.getParameterTypes())) { |
| 258 | overridden.add(m0); |
| 259 | } |
| 260 | } |
| 261 | |
| 262 | final List<Method> methods = newList(Arrays.asList(methodArray)); |
| 263 | methods.removeAll(overridden); |
| 264 | return methods; |
| 265 | } |
| 266 | |
| 267 | |
| 268 | } |