1 /*

     2  * Copyright (c) 1999, 2014, Oracle and/or its affiliates. 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package com.sun.jmx.snmp;

    27 

    28 

    29 import java.io.*;

    30 import java.util.Hashtable;

    31 import java.util.*;

    32 

    33 

    34 

    35 /** This class is used for implementing enumerated values.

    36  *

    37  * An enumeration is represented by a class derived from Enumerated.

    38  * The derived class defines what are the permitted values in the enumeration.

    39  *

    40  * An enumerated value is represented by an instance of the derived class.

    41  * It can be represented :

    42  *  - as an integer

    43  *  - as a string

    44  *

    45  * <p><b>This API is a Sun Microsystems internal API  and is subject

    46  * to change without notice.</b></p>

    47  */

    48 @SuppressWarnings("serial") // JDK implementation class

    49 abstract public class Enumerated  implements Serializable {

    50 

    51   /**

    52    * Construct an enumerated with a default value.

    53    * The default value is the first available in getIntTable().

    54     * @exception IllegalArgumentException One of the arguments passed to the method is illegal or inappropriate.

    55    */

    56   public Enumerated() throws IllegalArgumentException {

    57     Enumeration<Integer> e =getIntTable().keys();

    58     if (e.hasMoreElements()) {

    59       value = e.nextElement().intValue() ;

    60     }

    61     else {

    62       throw new IllegalArgumentException() ;

    63     }

    64   }

    65 

    66   /**

    67    * Construct an enumerated from its integer form.

    68    *

    69    * @param valueIndex The integer form.

    70    * @exception IllegalArgumentException One of the arguments passed to

    71    *            the method is illegal or inappropriate.

    72    */

    73   public Enumerated(int valueIndex) throws IllegalArgumentException {

    74     if (getIntTable().get(valueIndex) == null) {

    75       throw new IllegalArgumentException() ;

    76     }

    77     value = valueIndex ;

    78   }

    79 

    80   /**

    81    * Construct an enumerated from its Integer form.

    82    *

    83    * @param valueIndex The Integer form.

    84    * @exception IllegalArgumentException One of the arguments passed to

    85    *            the method is illegal or inappropriate.

    86    */

    87   public Enumerated(Integer valueIndex) throws IllegalArgumentException {

    88     if (getIntTable().get(valueIndex) == null) {

    89       throw new IllegalArgumentException() ;

    90     }

    91     value = valueIndex.intValue() ;

    92   }

    93 

    94 

    95   /**

    96    * Construct an enumerated from its string form.

    97    *

    98    * @param valueString The string form.

    99    * @exception IllegalArgumentException One of the arguments passed

   100    *  to the method is illegal or inappropriate.

   101    */

   102   public Enumerated(String valueString) throws IllegalArgumentException {

   103     Integer index = getStringTable().get(valueString) ;

   104     if (index == null) {

   105       throw new IllegalArgumentException() ;

   106     }

   107     else {

   108       value = index.intValue() ;

   109     }

   110   }

   111 

   112 

   113   /**

   114    * Return the integer form of the enumerated.

   115    *

   116    * @return The integer form

   117    */

   118 

   119   public int intValue() {

   120     return value ;

   121   }

   122 

   123 

   124   /**

   125    * Returns an Java enumeration of the permitted integers.

   126    *

   127    * @return An enumeration of Integer instances

   128    */

   129 

   130   public Enumeration<Integer> valueIndexes() {

   131     return getIntTable().keys() ;

   132   }

   133 

   134 

   135   /**

   136    * Returns an Java enumeration of the permitted strings.

   137    *

   138    * @return An enumeration of String instances

   139    */

   140 

   141   public Enumeration<String> valueStrings() {

   142     return getStringTable().keys() ;

   143   }

   144 

   145 

   146   /**

   147    * Compares this enumerated to the specified enumerated.

   148    *

   149    * The result is true if and only if the argument is not null

   150    * and is of the same class.

   151    *

   152    * @param obj The object to compare with.

   153    *

   154    * @return True if this and obj are the same; false otherwise

   155    */

   156   @Override

   157   public boolean equals(Object obj) {

   158 

   159     return ((obj != null) &&

   160             (getClass() == obj.getClass()) &&

   161             (value == ((Enumerated)obj).value)) ;

   162   }

   163 

   164 

   165   /**

   166    * Returns the hash code for this enumerated.

   167    *

   168    * @return A hash code value for this object.

   169    */

   170   @Override

   171   public int hashCode() {

   172     String hashString = getClass().getName() + String.valueOf(value) ;

   173     return hashString.hashCode() ;

   174   }

   175 

   176 

   177   /**

   178    * Returns the string form of this enumerated.

   179    *

   180    * @return The string for for this object.

   181    */

   182   @Override

   183   public String toString() {

   184     return getIntTable().get(value);

   185   }

   186 

   187 

   188   /**

   189    * Returns the hashtable of the integer forms.

   190    * getIntTable().get(x) returns the string form associated

   191    * to the integer x.

   192    *

   193    * This method must be implemented by the derived class.

   194    *

   195    * @return An hashtable for read-only purpose

   196    */

   197 

   198   protected abstract Hashtable<Integer,String>  getIntTable() ;

   199 

   200 

   201 

   202   /**

   203    * Returns the hashtable of the string forms.

   204    * getStringTable().get(s) returns the integer form associated

   205    * to the string s.

   206    *

   207    * This method must be implemented by the derived class.

   208    *

   209    * @return An hashtable for read-only purpose

   210    */

   211 

   212   protected abstract Hashtable<String,Integer> getStringTable() ;

   213 

   214 

   215   /**

   216    * This variable keeps the integer form of the enumerated.

   217    * The string form is retrieved using getIntTable().

   218    */

   219   protected int value ;

   220 

   221 }