Source for javax.management.MBeanConstructorInfo

   1: /* MBeanConstructorInfo.java -- Information about a bean's constructor.
   2:    Copyright (C) 2006 Free Software Foundation, Inc.
   3: 
   4: This file is part of GNU Classpath.
   5: 
   6: GNU Classpath is free software; you can redistribute it and/or modify
   7: it under the terms of the GNU General Public License as published by
   8: the Free Software Foundation; either version 2, or (at your option)
   9: any later version.
  10: 
  11: GNU Classpath is distributed in the hope that it will be useful, but
  12: WITHOUT ANY WARRANTY; without even the implied warranty of
  13: MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14: General Public License for more details.
  15: 
  16: You should have received a copy of the GNU General Public License
  17: along with GNU Classpath; see the file COPYING.  If not, write to the
  18: Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  19: 02110-1301 USA.
  20: 
  21: Linking this library statically or dynamically with other modules is
  22: making a combined work based on this library.  Thus, the terms and
  23: conditions of the GNU General Public License cover the whole
  24: combination.
  25: 
  26: As a special exception, the copyright holders of this library give you
  27: permission to link this library with independent modules to produce an
  28: executable, regardless of the license terms of these independent
  29: modules, and to copy and distribute the resulting executable under
  30: terms of your choice, provided that you also meet, for each linked
  31: independent module, the terms and conditions of the license of that
  32: module.  An independent module is a module which is not derived from
  33: or based on this library.  If you modify this library, you may extend
  34: this exception to your version of the library, but you are not
  35: obligated to do so.  If you do not wish to do so, delete this
  36: exception statement from your version. */
  37: 
  38: package javax.management;
  39: 
  40: import java.lang.reflect.Constructor;
  41: 
  42: import java.util.Arrays;
  43: 
  44: /**
  45:  * Describes the constructors of a management bean.
  46:  * The information in this class is immutable as standard.
  47:  * Of course, subclasses may change this, but this
  48:  * behaviour is not recommended.
  49:  *
  50:  * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
  51:  * @since 1.5
  52:  */
  53: public class MBeanConstructorInfo
  54:   extends MBeanFeatureInfo
  55:   implements Cloneable
  56: {
  57: 
  58:   /**
  59:    * Compatible with JDK 1.5
  60:    */
  61:   private static final long serialVersionUID = 4433990064191844427L;
  62: 
  63:   /**
  64:    * The signature of the constructor i.e. the argument types.
  65:    */
  66:   private MBeanParameterInfo[] signature;
  67: 
  68:   /**
  69:    * Constructs a @link{MBeanConstructorInfo} with the specified
  70:    * description using the given constructor.  Each parameter is
  71:    * described merely by its type; the name and description are
  72:    * <code>null</code>.
  73:    *
  74:    * @param desc a description of the attribute.
  75:    * @param cons the constructor.
  76:    */
  77:   public MBeanConstructorInfo(String desc, Constructor cons)
  78:   {
  79:     super(cons.getName(), desc);
  80:     Class[] paramTypes = cons.getParameterTypes();
  81:     signature = new MBeanParameterInfo[paramTypes.length];
  82:     for (int a = 0; a < paramTypes.length; ++a)
  83:       signature[a] = new MBeanParameterInfo(null,
  84:                         paramTypes[a].getName(),
  85:                         null);
  86:   }
  87: 
  88:   /**
  89:    * Constructs a @link{MBeanConstructorInfo} with the specified
  90:    * name, description and parameter information. A <code>null</code>
  91:    * value for the parameter information is the same as passing in
  92:    * an empty array.
  93:    *
  94:    * @param name the name of the constructor.
  95:    * @param desc a description of the attribute.
  96:    * @param sig the signature of the constructor, as a series
  97:    *            of {@link MBeanParameterInfo} objects, one for
  98:    *            each parameter.
  99:    */
 100:   public MBeanConstructorInfo(String name, String desc,
 101:                   MBeanParameterInfo[] sig)
 102:   {
 103:     super(name, desc);
 104:     if (sig == null)
 105:       signature = new MBeanParameterInfo[0];
 106:     else
 107:       signature = sig;
 108:   }
 109: 
 110:   /**
 111:    * Returns a clone of this instance.  The clone is created
 112:    * using just the method provided by {@link java.lang.Object}.
 113:    * Thus, the clone is just a shallow clone as returned by
 114:    * that method, and does not contain any deeper cloning based
 115:    * on the subject of this class.
 116:    *
 117:    * @return a clone of this instance.
 118:    * @see java.lang.Cloneable
 119:    */
 120:   public Object clone()
 121:   {
 122:     try
 123:       {
 124:     return super.clone();
 125:       }
 126:     catch (CloneNotSupportedException e)
 127:       {
 128:     /* This shouldn't happen; we implement Cloneable */
 129:     throw new IllegalStateException("clone() called on " +
 130:                     "non-cloneable object.");
 131:       }
 132:   }
 133: 
 134:   /**
 135:    * Compares this feature with the supplied object.  This returns
 136:    * true iff the object is an instance of {@link
 137:    * MBeanConstructorInfo}, {@link Object#equals()} returns true for a
 138:    * comparison of both the name and description of this notification
 139:    * with that of the specified object (performed by the superclass),
 140:    * and the two signature arrays contain the same elements in the
 141:    * same order (but one may be longer than the other).
 142:    *
 143:    * @param obj the object to compare.
 144:    * @return true if the object is a {@link MBeanConstructorInfo}
 145:    *         instance, 
 146:    *         <code>name.equals(object.getName())</code>,
 147:    *         <code>description.equals(object.getDescription())</code>
 148:    *         and the corresponding elements of the signature arrays are
 149:    *         equal.
 150:    */
 151:   public boolean equals(Object obj)
 152:   {
 153:     if (!(obj instanceof MBeanConstructorInfo))
 154:       return false;
 155:     if (!(super.equals(obj)))
 156:       return false;
 157:     MBeanConstructorInfo o = (MBeanConstructorInfo) obj;
 158:     MBeanParameterInfo[] sig = o.getSignature();
 159:     for (int a = 0; a < signature.length; ++a)
 160:       {
 161:     if (a == sig.length)
 162:       return true;
 163:     if (!(signature[a].equals(sig[a])))
 164:       return false;
 165:       }
 166:     return true;
 167:   }
 168:   
 169:   /**
 170:    * Returns the constructor's signature, in the form of
 171:    * information on each parameter.  Each parameter is
 172:    * described by an instance of {@link MBeanParameterInfo}.
 173:    * The returned array is a shallow copy of the array used
 174:    * by this instance, so changing which elements are stored
 175:    * in the array won't affect the array used by this, but
 176:    * changing the actual elements will affect the ones used
 177:    * here.
 178:    *
 179:    * @return an array of {@link MBeanParameterInfo} objects,
 180:    *         describing the constructor parameters.
 181:    */
 182:   public MBeanParameterInfo[] getSignature()
 183:   {
 184:     return (MBeanParameterInfo[]) signature.clone();
 185:   }
 186: 
 187:   /**
 188:    * Returns the hashcode of the constructor information as the sum
 189:    * of the hashcode of the superclass and the hashcode of the parameter
 190:    * array.
 191:    *
 192:    * @return the hashcode of the constructor information.
 193:    */
 194:   public int hashCode()
 195:   {
 196:     return super.hashCode() + Arrays.hashCode(signature);
 197:   }
 198: 
 199:   /**
 200:    * <p>
 201:    * Returns a textual representation of this instance.  This
 202:    * is constructed using the class name
 203:    * (<code>javax.management.MBeanConstructorInfo</code>),
 204:    * the name and description of the constructor and the 
 205:    * contents of the array of parameters.
 206:    * </p>
 207:    * <p>
 208:    * As instances of this class are immutable, the return value
 209:    * is computed just once for each instance and reused
 210:    * throughout its life.
 211:    * </p>
 212:    *
 213:    * @return a @link{java.lang.String} instance representing
 214:    *         the instance in textual form.
 215:    */
 216:   public String toString()
 217:   {
 218:     if (string == null)
 219:       {
 220:     super.toString();
 221:     string = string.substring(0, string.length() - 1) 
 222:       + ",signature=" + Arrays.toString(signature)
 223:       + "]";
 224:       }
 225:     return string;
 226:   }
 227: 
 228: }