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: import java.lang.reflect.Type;
  42: 
  43: import java.util.Arrays;
  44: 
  45: /**
  46:  * Describes the constructors of a management bean.
  47:  * The information in this class is immutable as standard.
  48:  * Of course, subclasses may change this, but this
  49:  * behaviour is not recommended.
  50:  *
  51:  * @author Andrew John Hughes (gnu_andrew@member.fsf.org)
  52:  * @since 1.5
  53:  */
  54: public class MBeanConstructorInfo
  55:   extends MBeanFeatureInfo
  56:   implements Cloneable
  57: {
  58: 
  59:   /**
  60:    * Compatible with JDK 1.5
  61:    */
  62:   private static final long serialVersionUID = 4433990064191844427L;
  63: 
  64:   /**
  65:    * The signature of the constructor i.e. the argument types.
  66:    */
  67:   private MBeanParameterInfo[] signature;
  68: 
  69:   /**
  70:    * Constructs a @link{MBeanConstructorInfo} with the specified
  71:    * description using the given constructor.  Each parameter is
  72:    * described merely by its type; the name and description are
  73:    * <code>null</code>.
  74:    *
  75:    * @param desc a description of the attribute.
  76:    * @param cons the constructor.
  77:    */
  78:   public MBeanConstructorInfo(String desc, Constructor cons)
  79:   {
  80:     super(cons.getName(), desc);
  81:     Type[] paramTypes = cons.getGenericParameterTypes();
  82:     signature = new MBeanParameterInfo[paramTypes.length];
  83:     for (int a = 0; a < paramTypes.length; ++a)
  84:       {
  85:     Type t = paramTypes[a];
  86:     if (t instanceof Class)
  87:       signature[a] = new MBeanParameterInfo(null,
  88:                         ((Class) t).getName(),
  89:                         null);
  90:     else
  91:       signature[a] = new MBeanParameterInfo(null, t.toString(), null);
  92:       }
  93:   }
  94: 
  95:   /**
  96:    * Constructs a @link{MBeanConstructorInfo} with the specified
  97:    * name, description and parameter information. A <code>null</code>
  98:    * value for the parameter information is the same as passing in
  99:    * an empty array.  A copy of the parameter array is taken, so
 100:    * later changes have no effect.
 101:    *
 102:    * @param name the name of the constructor.
 103:    * @param desc a description of the constructor.
 104:    * @param sig the signature of the constructor, as a series
 105:    *            of {@link MBeanParameterInfo} objects, one for
 106:    *            each parameter.
 107:    */
 108:   public MBeanConstructorInfo(String name, String desc,
 109:                   MBeanParameterInfo[] sig)
 110:   {
 111:     super(name, desc);
 112:     if (sig == null)
 113:       signature = new MBeanParameterInfo[0];
 114:     else
 115:       {
 116:     signature = new MBeanParameterInfo[sig.length];
 117:     System.arraycopy(sig, 0, signature, 0, sig.length);
 118:       }
 119:   }
 120: 
 121:   /**
 122:    * Returns a clone of this instance.  The clone is created
 123:    * using just the method provided by {@link java.lang.Object}.
 124:    * Thus, the clone is just a shallow clone as returned by
 125:    * that method, and does not contain any deeper cloning based
 126:    * on the subject of this class.
 127:    *
 128:    * @return a clone of this instance.
 129:    * @see java.lang.Cloneable
 130:    */
 131:   public Object clone()
 132:   {
 133:     try
 134:       {
 135:     return super.clone();
 136:       }
 137:     catch (CloneNotSupportedException e)
 138:       {
 139:     /* This shouldn't happen; we implement Cloneable */
 140:     throw new IllegalStateException("clone() called on " +
 141:                     "non-cloneable object.");
 142:       }
 143:   }
 144: 
 145:   /**
 146:    * Compares this feature with the supplied object.  This returns
 147:    * true iff the object is an instance of {@link
 148:    * MBeanConstructorInfo}, {@link Object#equals()} returns true for a
 149:    * comparison of both the name and description of this notification
 150:    * with that of the specified object (performed by the superclass),
 151:    * and the two signature arrays contain the same elements in the
 152:    * same order (but one may be longer than the other).
 153:    *
 154:    * @param obj the object to compare.
 155:    * @return true if the object is a {@link MBeanConstructorInfo}
 156:    *         instance, 
 157:    *         <code>name.equals(object.getName())</code>,
 158:    *         <code>description.equals(object.getDescription())</code>
 159:    *         and the corresponding elements of the signature arrays are
 160:    *         equal.
 161:    */
 162:   public boolean equals(Object obj)
 163:   {
 164:     if (!(obj instanceof MBeanConstructorInfo))
 165:       return false;
 166:     if (!(super.equals(obj)))
 167:       return false;
 168:     MBeanConstructorInfo o = (MBeanConstructorInfo) obj;
 169:     MBeanParameterInfo[] sig = o.getSignature();
 170:     for (int a = 0; a < signature.length; ++a)
 171:       {
 172:     if (a == sig.length)
 173:       return true;
 174:     if (!(signature[a].equals(sig[a])))
 175:       return false;
 176:       }
 177:     return true;
 178:   }
 179:   
 180:   /**
 181:    * Returns the constructor's signature, in the form of
 182:    * information on each parameter.  Each parameter is
 183:    * described by an instance of {@link MBeanParameterInfo}.
 184:    * The returned array is a shallow copy of the array used
 185:    * by this instance, so changing which elements are stored
 186:    * in the array won't affect the array used by this, but
 187:    * changing the actual elements will affect the ones used
 188:    * here.
 189:    *
 190:    * @return an array of {@link MBeanParameterInfo} objects,
 191:    *         describing the constructor parameters.
 192:    */
 193:   public MBeanParameterInfo[] getSignature()
 194:   {
 195:     return (MBeanParameterInfo[]) signature.clone();
 196:   }
 197: 
 198:   /**
 199:    * Returns the hashcode of the constructor information as the sum
 200:    * of the hashcode of the superclass and the hashcode of the parameter
 201:    * array.
 202:    *
 203:    * @return the hashcode of the constructor information.
 204:    */
 205:   public int hashCode()
 206:   {
 207:     return super.hashCode() + Arrays.hashCode(signature);
 208:   }
 209: 
 210:   /**
 211:    * <p>
 212:    * Returns a textual representation of this instance.  This
 213:    * is constructed using the class name
 214:    * (<code>javax.management.MBeanConstructorInfo</code>),
 215:    * the name and description of the constructor and the 
 216:    * contents of the array of parameters.
 217:    * </p>
 218:    * <p>
 219:    * As instances of this class are immutable, the return value
 220:    * is computed just once for each instance and reused
 221:    * throughout its life.
 222:    * </p>
 223:    *
 224:    * @return a @link{java.lang.String} instance representing
 225:    *         the instance in textual form.
 226:    */
 227:   public String toString()
 228:   {
 229:     if (string == null)
 230:       {
 231:     super.toString();
 232:     string = string.substring(0, string.length() - 1) 
 233:       + ",signature=" + Arrays.toString(signature)
 234:       + "]";
 235:       }
 236:     return string;
 237:   }
 238: 
 239: }