Fix to enable anonymous inner classes as Enums for functionality

git-svn-id: https://svn.apache.org/repos/asf/jakarta/commons/proper/lang/trunk@137220 13f79535-47bb-0310-9956-ffa450edef68

src/java/org/apache/commons/lang/enum/Enum.java

@@ -111,12 +111,52 @@ import java.util.Map;
  * Unfortunately, Java restrictions require these to be coded as shown in each subclass.
  * An alternative choice is to use the {@link EnumUtils} class.
  * <p>
+ * The enums can have functionality by using anonymous inner classes
+ * [Effective Java, Bloch01]:
+ * <pre>
+ * public abstract class OperationEnum extends Enum {
+ *   public static final OperationEnum PLUS = new OperationEnum("Plus") {
+ *     public double eval(double a, double b) {
+ *       return (a + b);
+ *     }
+ *   };
+ *   public static final OperationEnum MINUS = new OperationEnum("Minus") {
+ *     public double eval(double a, double b) {
+ *       return (a - b);
+ *     }
+ *   };
+ *
+ *   private OperationEnum(String color) {
+ *     super(color);
+ *   }
+ * 
+ *   public abstract double eval(double a, double b);
+ * 
+ *   public static OperationEnum getEnum(String name) {
+ *     return (OperationEnum) getEnum(OperationEnum.class, name);
+ *   }
+ * 
+ *   public static Map getEnumMap() {
+ *     return getEnumMap(OperationEnum.class);
+ *   }
+ * 
+ *   public static List getEnumList() {
+ *     return getEnumList(OperationEnum.class);
+ *   }
+ * 
+ *   public static Iterator iterator() {
+ *     return iterator(OperationEnum.class);
+ *   }
+ * }
+ * </pre>
+ * <p>
  * <em>NOTE:</em> This class originated in the Jakarta Avalon project.
  * </p>
  *
  * @author Stephen Colebourne
+ * @author Chris Webb
  * @since 1.0
- * @version $Id: Enum.java,v 1.5 2002/12/23 00:17:06 scolebourne Exp $
+ * @version $Id: Enum.java,v 1.6 2002/12/31 22:39:39 scolebourne Exp $
  */
 public abstract class Enum implements Comparable, Serializable {
     /**
@@ -160,10 +200,11 @@ public abstract class Enum implements Comparable, Serializable {
             throw new IllegalArgumentException("The Enum name must not be empty");
         }
         iName = name;
-        Entry entry = (Entry) cEnumClasses.get(getClass().getName());
+        String className = Enum.getEnumClassName(getClass());
+        Entry entry = (Entry) cEnumClasses.get(className);
         if (entry == null) {
             entry = new Entry();
-            cEnumClasses.put(getClass().getName(), entry);
+            cEnumClasses.put(className, entry);
         }
         if (entry.map.containsKey(name)) {
             throw new IllegalArgumentException("The Enum name must be unique, '" + name + "' has already been added");
@@ -178,22 +219,25 @@ public abstract class Enum implements Comparable, Serializable {
      * @return the resolved object
      */
     protected Object readResolve() {
-        return Enum.getEnum(getClass(), getName());
+        Entry entry = (Entry) cEnumClasses.get(Enum.getEnumClassName(getClass()));
+        if (entry == null) {
+            return null;
+        }
+        return (Enum) entry.map.get(getName());
     }
+    
+    //--------------------------------------------------------------------------------
 
     /**
      * Gets an Enum object by class and name.
      * 
-     * @param enumClass  the class of the Enum to get
+     * @param enumClass  the class of the Enum to get, must not be null
      * @param name  the name of the Enum to get, may be null
      * @return the enum object, or null if the enum does not exist
      * @throws IllegalArgumentException if the enum class is null
      */
     protected static Enum getEnum(Class enumClass, String name) {
-        if (enumClass == null) {
+        Entry entry = getEntry(enumClass);
-            throw new IllegalArgumentException("The Enum Class must not be null");
-        }
-        Entry entry = (Entry) cEnumClasses.get(enumClass.getName());
         if (entry == null) {
             return null;
         }
@@ -204,19 +248,13 @@ public abstract class Enum implements Comparable, Serializable {
      * Gets the Map of Enum objects by name using the Enum class.
      * If the requested class has no enum objects an empty Map is returned.
      * 
-     * @param enumClass  the class of the Enum to get
+     * @param enumClass  the class of the Enum to get, must not be null
      * @return the enum object Map
      * @throws IllegalArgumentException if the enum class is null
      * @throws IllegalArgumentException if the enum class is not a subclass of Enum
      */
     protected static Map getEnumMap(Class enumClass) {
-        if (enumClass == null) {
+        Entry entry = getEntry(enumClass);
-            throw new IllegalArgumentException("The Enum Class must not be null");
-        }
-        if (Enum.class.isAssignableFrom(enumClass) == false) {
-            throw new IllegalArgumentException("The Class must be a subclass of Enum");
-        }
-        Entry entry = (Entry) cEnumClasses.get(enumClass.getName());
         if (entry == null) {
             return EMPTY_MAP;
         }
@@ -228,19 +266,13 @@ public abstract class Enum implements Comparable, Serializable {
      * The list is in the order that the objects were created (source code order).
      * If the requested class has no enum objects an empty List is returned.
      * 
-     * @param enumClass  the class of the Enum to get
+     * @param enumClass  the class of the Enum to get, must not be null
      * @return the enum object Map
      * @throws IllegalArgumentException if the enum class is null
      * @throws IllegalArgumentException if the enum class is not a subclass of Enum
      */
     protected static List getEnumList(Class enumClass) {
-        if (enumClass == null) {
+        Entry entry = getEntry(enumClass);
-            throw new IllegalArgumentException("The Enum Class must not be null");
-        }
-        if (Enum.class.isAssignableFrom(enumClass) == false) {
-            throw new IllegalArgumentException("The Class must be a subclass of Enum");
-        }
-        Entry entry = (Entry) cEnumClasses.get(enumClass.getName());
         if (entry == null) {
             return Collections.EMPTY_LIST;
         }
@@ -252,7 +284,7 @@ public abstract class Enum implements Comparable, Serializable {
      * The iterator is in the order that the objects were created (source code order).
      * If the requested class has no enum objects an empty Iterator is returned.
      * 
-     * @param enumClass  the class of the Enum to get
+     * @param enumClass  the class of the Enum to get, must not be null
      * @return an iterator of the Enum objects
      * @throws IllegalArgumentException if the enum class is null
      * @throws IllegalArgumentException if the enum class is not a subclass of Enum
@@ -261,6 +293,47 @@ public abstract class Enum implements Comparable, Serializable {
         return Enum.getEnumList(enumClass).iterator();
     }
 
+    /**
+     * Gets an entry from the map of Enums.
+     * 
+     * @param enumClass  the class of the Enum to get
+     * @return the enum entry
+     */
+    private static Entry getEntry(Class enumClass) {
+        if (enumClass == null) {
+            throw new IllegalArgumentException("The Enum Class must not be null");
+        }
+        if (Enum.class.isAssignableFrom(enumClass) == false) {
+            throw new IllegalArgumentException("The Class must be a subclass of Enum");
+        }
+        Entry entry = (Entry) cEnumClasses.get(enumClass.getName());
+        return entry;
+    }
+    
+    /**
+     * Convert a class to a class name accounting for inner classes.
+     * 
+     * @param cls  the class to get the name for
+     * @return the class name
+     */
+    protected static String getEnumClassName(Class cls) {
+        String className = cls.getName();
+        int index = className.lastIndexOf('$');
+        if (index > -1) {
+            // is it an anonymous inner class?
+            String inner = className.substring(index + 1);
+            if (inner.length() > 0 &&
+                inner.charAt(0) >= '0' &&
+                inner.charAt(0) < '9') {
+                // Strip off anonymous inner class reference.
+                className = className.substring(0, index);
+            }
+        }
+        return className;
+    }
+
+    //--------------------------------------------------------------------------------
+
     /**
      * Retrieve the name of this Enum item, set in the constructor.
      * 
@@ -343,7 +416,7 @@ public abstract class Enum implements Comparable, Serializable {
      * the type name.
      */
     public String toString() {
-        String shortName = getClass().getName();
+        String shortName = Enum.getEnumClassName(getClass());
         int pos = shortName.lastIndexOf('.');
         if (pos != -1) {
             shortName = shortName.substring(pos + 1);

src/java/org/apache/commons/lang/enum/ValuedEnum.java

@@ -130,7 +130,7 @@ import java.util.List;
  *
  * @author Stephen Colebourne
  * @since 1.0
- * @version $Id: ValuedEnum.java,v 1.3 2002/12/23 00:17:06 scolebourne Exp $
+ * @version $Id: ValuedEnum.java,v 1.4 2002/12/31 22:39:39 scolebourne Exp $
  */
 public abstract class ValuedEnum extends Enum {
     /**
@@ -204,7 +204,7 @@ public abstract class ValuedEnum extends Enum {
      * stripped from the type name.
      */
     public String toString() {
-        String shortName = getClass().getName();
+        String shortName = Enum.getEnumClassName(getClass());
         int pos = shortName.lastIndexOf('.');
         if (pos != -1) {
             shortName = shortName.substring(pos + 1);

src/test/org/apache/commons/lang/enum/EnumTest.java

@@ -65,8 +65,8 @@ import org.apache.commons.lang.SerializationUtils;
 /**
  * Test cases for the {@link Enum} class.
  *
- * @author <a href="mailto:scolebourne@joda.org">Stephen Colebourne</a>
+ * @author Stephen Colebourne
- * @version $Id: EnumTest.java,v 1.4 2002/11/06 19:14:43 bayard Exp $
+ * @version $Id: EnumTest.java,v 1.5 2002/12/31 22:39:39 scolebourne Exp $
  */
 
 public final class EnumTest extends TestCase {
@@ -182,4 +182,46 @@ public final class EnumTest extends TestCase {
         }
     }
 
+    public void testOperationGet() {
+        assertSame(OperationEnum.PLUS, OperationEnum.getEnum("Plus"));
+        assertSame(OperationEnum.MINUS, OperationEnum.getEnum("Minus"));
+        assertSame(null, OperationEnum.getEnum("Pink"));
+    }
+
+    public void testOperationSerialization() {
+        assertSame(OperationEnum.PLUS, SerializationUtils.clone(OperationEnum.PLUS));
+        assertSame(OperationEnum.MINUS, SerializationUtils.clone(OperationEnum.MINUS));
+    }
+
+    public void testOperationToString() {
+        assertEquals("OperationEnum[Plus]", OperationEnum.PLUS.toString());
+    }
+
+    public void testOperationList() {
+        List list = OperationEnum.getEnumList();
+        assertNotNull(list);
+        assertEquals(2, list.size());
+        assertEquals(list.size(), OperationEnum.getEnumMap().keySet().size());
+        
+        Iterator it = list.iterator();
+        assertSame(OperationEnum.PLUS, it.next());
+        assertSame(OperationEnum.MINUS, it.next());
+    }
+
+    public void testOperationMap() {
+        Map map = OperationEnum.getEnumMap();
+        assertNotNull(map);
+        assertEquals(map.keySet().size(), OperationEnum.getEnumList().size());
+        
+        assertTrue(map.containsValue(OperationEnum.PLUS));
+        assertTrue(map.containsValue(OperationEnum.MINUS));
+        assertSame(OperationEnum.PLUS, map.get("Plus"));
+        assertSame(OperationEnum.MINUS, map.get("Minus"));
+    }
+
+    public void testOperationCalculation() {
+        assertEquals(3, OperationEnum.PLUS.eval(1, 2));
+        assertEquals(-1, OperationEnum.MINUS.eval(1, 2));
+    }
+
 }

src/test/org/apache/commons/lang/enum/OperationEnum.java

@@ -0,0 +1,98 @@
+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2002 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution, if
+ *    any, must include the following acknowlegement:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowlegement may appear in the software itself,
+ *    if and wherever such third-party acknowlegements normally appear.
+ *
+ * 4. The names "The Jakarta Project", "Commons", and "Apache Software
+ *    Foundation" must not be used to endorse or promote products derived
+ *    from this software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache"
+ *    nor may "Apache" appear in their names without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+package org.apache.commons.lang.enum;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+/**
+ * Operator enumeration.
+ *
+ * @author Stephen Colebourne
+ * @version $Id: OperationEnum.java,v 1.1 2002/12/31 22:39:39 scolebourne Exp $
+ */
+public abstract class OperationEnum extends Enum {
+    public static final OperationEnum PLUS = new OperationEnum("Plus") {
+        public int eval(int a, int b) {
+            return (a + b);
+        }
+    };
+    public static final OperationEnum MINUS = new OperationEnum("Minus") {
+        public int eval(int a, int b) {
+            return (a - b);
+        }
+    };
+
+    private OperationEnum(String name) {
+        super(name);
+    }
+
+    public abstract int eval(int a, int b);
+
+    public static OperationEnum getEnum(String name) {
+        return (OperationEnum) getEnum(OperationEnum.class, name);
+    }
+
+    public static Map getEnumMap() {
+        return getEnumMap(OperationEnum.class);
+    }
+
+    public static List getEnumList() {
+        return getEnumList(OperationEnum.class);
+    }
+
+    public static Iterator iterator() {
+        return iterator(OperationEnum.class);
+    }
+}