[LANG-146] Enum does not support inner sub-classes

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.0
• Fix Version/s: 2.0

Environment

Operating System: other
Platform: PC

• Bugzilla Id: 15439
• Assignee: Unassigned
• Reporter: Chris Webb
• Created: 17/Dec/02 20:38
• Updated: 16/May/06 12:44
• Resolved: 16/May/06 12:44

Description

The org.apache.commons.lang.enum.Enum class does not support the following
construct of static inner anonymous sub-classed constants:

public abstract class MyEnum extends Enum {
public static final MyEnum ENUM1 = new MyEnum("enum1") {
public String getValue()

{ return "X"; }

};

public static final MyEnum ENUM2 = new MyEnum("enum2") {
public String getValue()

{ return "Y"; }

};

/**

• Constructor.
  */
  protected MyEnum(String name) { super(name); }

/**

• Returns a value.
• Creation date: (16/12/2002 13:25:35)
  */
  public abstract String getValue();
  }

ENUM1 and ENUM2 are assigned anonymous inner class names 'MyEnum$0' and
'MyEnum$1' respectively instead of the super class 'MyEnum' when added to the
list of enumerations kept in the Enum super class via the Enum constructor.

A simple work around is to strip the inner class descriminator off the class
name in the Enum constructor, i.e.

protected Enum(String name) {
super();
if (name == null || name.length() == 0)

{ throw new IllegalArgumentException("The Enum name must not be empty"); }

iName = name;

// Retrieve class name.
String className = getClass().getName();

// Search for inner class.
int index = className.lastIndexOf('$');
if (index > -1)

{ // Strip off inner class reference. className = className.substring(0, index); }

Entry entry = (Entry) cEnumClasses.get(className);

if (entry == null)

{ entry = new Entry(); cEnumClasses.put(className, entry); }

if (entry.map.containsKey(name))

{ throw new IllegalArgumentException("The Enum name must be unique, '" + name + "' has already been added"); }

entry.map.put(name, this);
entry.list.add(this);
}