001/* MBeanConstructorInfo.java -- Information about a bean's constructor. 002 Copyright (C) 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038package javax.management; 039 040import java.lang.reflect.Constructor; 041import java.lang.reflect.Type; 042 043import java.util.Arrays; 044 045/** 046 * Describes the constructors of a management bean. 047 * The information in this class is immutable as standard. 048 * Of course, subclasses may change this, but this 049 * behaviour is not recommended. 050 * 051 * @author Andrew John Hughes (gnu_andrew@member.fsf.org) 052 * @since 1.5 053 */ 054public class MBeanConstructorInfo 055 extends MBeanFeatureInfo 056 implements Cloneable 057{ 058 059 /** 060 * Compatible with JDK 1.5 061 */ 062 private static final long serialVersionUID = 4433990064191844427L; 063 064 /** 065 * The signature of the constructor i.e. the argument types. 066 */ 067 private MBeanParameterInfo[] signature; 068 069 /** 070 * Constructs a @link{MBeanConstructorInfo} with the specified 071 * description using the given constructor. Each parameter is 072 * described merely by its type; the name and description are 073 * <code>null</code>. 074 * 075 * @param desc a description of the attribute. 076 * @param cons the constructor. 077 */ 078 // API issue with lack of <?> on Constructor 079 @SuppressWarnings("rawtypes") 080 public MBeanConstructorInfo(String desc, Constructor cons) 081 { 082 super(cons.getName(), desc); 083 Type[] paramTypes = cons.getGenericParameterTypes(); 084 signature = new MBeanParameterInfo[paramTypes.length]; 085 for (int a = 0; a < paramTypes.length; ++a) 086 { 087 Type t = paramTypes[a]; 088 if (t instanceof Class) 089 signature[a] = new MBeanParameterInfo(null, 090 ((Class<?>) t).getName(), 091 null); 092 else 093 signature[a] = new MBeanParameterInfo(null, t.toString(), null); 094 } 095 } 096 097 /** 098 * Constructs a @link{MBeanConstructorInfo} with the specified 099 * name, description and parameter information. A <code>null</code> 100 * value for the parameter information is the same as passing in 101 * an empty array. A copy of the parameter array is taken, so 102 * later changes have no effect. 103 * 104 * @param name the name of the constructor. 105 * @param desc a description of the constructor. 106 * @param sig the signature of the constructor, as a series 107 * of {@link MBeanParameterInfo} objects, one for 108 * each parameter. 109 */ 110 public MBeanConstructorInfo(String name, String desc, 111 MBeanParameterInfo[] sig) 112 { 113 super(name, desc); 114 if (sig == null) 115 signature = new MBeanParameterInfo[0]; 116 else 117 { 118 signature = new MBeanParameterInfo[sig.length]; 119 System.arraycopy(sig, 0, signature, 0, sig.length); 120 } 121 } 122 123 /** 124 * Returns a clone of this instance. The clone is created 125 * using just the method provided by {@link java.lang.Object}. 126 * Thus, the clone is just a shallow clone as returned by 127 * that method, and does not contain any deeper cloning based 128 * on the subject of this class. 129 * 130 * @return a clone of this instance. 131 * @see java.lang.Cloneable 132 */ 133 public Object clone() 134 { 135 try 136 { 137 return super.clone(); 138 } 139 catch (CloneNotSupportedException e) 140 { 141 /* This shouldn't happen; we implement Cloneable */ 142 throw new IllegalStateException("clone() called on " + 143 "non-cloneable object."); 144 } 145 } 146 147 /** 148 * Compares this feature with the supplied object. This returns 149 * true iff the object is an instance of {@link 150 * MBeanConstructorInfo}, {@link Object#equals()} returns true for a 151 * comparison of both the name and description of this notification 152 * with that of the specified object (performed by the superclass), 153 * and the two signature arrays contain the same elements in the 154 * same order (but one may be longer than the other). 155 * 156 * @param obj the object to compare. 157 * @return true if the object is a {@link MBeanConstructorInfo} 158 * instance, 159 * <code>name.equals(object.getName())</code>, 160 * <code>description.equals(object.getDescription())</code> 161 * and the corresponding elements of the signature arrays are 162 * equal. 163 */ 164 public boolean equals(Object obj) 165 { 166 if (!(obj instanceof MBeanConstructorInfo)) 167 return false; 168 if (!(super.equals(obj))) 169 return false; 170 MBeanConstructorInfo o = (MBeanConstructorInfo) obj; 171 MBeanParameterInfo[] sig = o.getSignature(); 172 for (int a = 0; a < signature.length; ++a) 173 { 174 if (a == sig.length) 175 return true; 176 if (!(signature[a].equals(sig[a]))) 177 return false; 178 } 179 return true; 180 } 181 182 /** 183 * Returns the constructor's signature, in the form of 184 * information on each parameter. Each parameter is 185 * described by an instance of {@link MBeanParameterInfo}. 186 * The returned array is a shallow copy of the array used 187 * by this instance, so changing which elements are stored 188 * in the array won't affect the array used by this, but 189 * changing the actual elements will affect the ones used 190 * here. 191 * 192 * @return an array of {@link MBeanParameterInfo} objects, 193 * describing the constructor parameters. 194 */ 195 public MBeanParameterInfo[] getSignature() 196 { 197 return (MBeanParameterInfo[]) signature.clone(); 198 } 199 200 /** 201 * Returns the hashcode of the constructor information as the sum 202 * of the hashcode of the superclass and the hashcode of the parameter 203 * array. 204 * 205 * @return the hashcode of the constructor information. 206 */ 207 public int hashCode() 208 { 209 return super.hashCode() + Arrays.hashCode(signature); 210 } 211 212 /** 213 * <p> 214 * Returns a textual representation of this instance. This 215 * is constructed using the class name 216 * (<code>javax.management.MBeanConstructorInfo</code>), 217 * the name and description of the constructor and the 218 * contents of the array of parameters. 219 * </p> 220 * <p> 221 * As instances of this class are immutable, the return value 222 * is computed just once for each instance and reused 223 * throughout its life. 224 * </p> 225 * 226 * @return a @link{java.lang.String} instance representing 227 * the instance in textual form. 228 */ 229 public String toString() 230 { 231 if (string == null) 232 { 233 super.toString(); 234 string = string.substring(0, string.length() - 1) 235 + ",signature=" + Arrays.toString(signature) 236 + "]"; 237 } 238 return string; 239 } 240 241}