Use Collections.unmodifiableCollection() instead of obsolete Immutable.Collection class.

Delete that class, it's not needed, since Java 5 Collections Framework.

src/java/org/jivesoftware/openfire/group/DefaultGroupPropertyMap.java

@@ -5,6 +5,7 @@ import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.util.AbstractSet;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.Iterator;
 import java.util.Map;
@@ -13,7 +14,6 @@ import java.util.Set;
 
 import org.jivesoftware.database.DbConnectionManager;
 import org.jivesoftware.openfire.event.GroupEventDispatcher;
-import org.jivesoftware.util.Immutable;
 import org.jivesoftware.util.PersistableMap;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
@@ -113,7 +113,7 @@ public class DefaultGroupPropertyMap<K,V> extends PersistableMap<K,V> {
 	@Override
 	public Collection<V> values() {
 		// custom class needed here to suppress value.remove()
-		return (Collection<V>) new Immutable.Collection<V>(super.values());
+		return Collections.unmodifiableCollection(super.values());
 	}
 
 	@Override

src/java/org/jivesoftware/util/Immutable.java

-package org.jivesoftware.util;
-
-import java.util.AbstractMap;
-import java.util.AbstractSet;
-import java.util.Collections;
-import java.util.Set;
-
-public class Immutable {
-	
-	/**
-	 * Wraps an existing {@link Collection} to provide read-only access to its contents.
-	 */
-	public static class Collection<V> extends java.util.AbstractCollection<V> {
-
-		private java.util.Collection<V> delegate;
-		
-		public Collection(java.util.Collection<V> delegate) {
-			this.delegate = delegate;
-		}
-
-		@Override
-		public Iterator<V> iterator() {
-			return new Iterator<V>(delegate.iterator());
-		}
-
-		@Override
-		public int size() {
-			return delegate.size();
-		}
-	}
-
-	/**
-	 * Read-only {@link Iterator} prevents removal of objects
-	 */
-	public static class Iterator<V> implements java.util.Iterator<V> {
-
-		private java.util.Iterator<V> delegate;
-		
-		public Iterator(java.util.Iterator<V> delegate) {
-			this.delegate = delegate;
-		}
-		public boolean hasNext() {
-			return delegate.hasNext();
-		}
-
-		public V next() {
-			return delegate.next();
-		}
-
-		public void remove() {
-			throw new UnsupportedOperationException();
-		}
-	}
-	
-	/**
-	 * Wraps a {@link Map} to provide read-only access to its elements.
-	 */
-	public static class Map<K,V> extends AbstractMap<K,V> {
-
-		private java.util.Map<K,V> backingMap;
-		
-		/**
-		 * Use this constructor to provide a pre-populated map that will be
-		 * made read-only via this wrapper class
-		 * @param backingMap
-		 */
-		public Map(java.util.Map<K,V> backingMap) {
-			this.backingMap = backingMap;
-		}
-		/**
-		 * Default constructor (empty map)
-		 */
-		public Map() { }
-
-		@Override
-		public Set<Map.Entry<K,V>> entrySet() {
-			if (backingMap == null) {
-				return Collections.emptySet();
-			} else {
-				return new AbstractSet<Map.Entry<K,V>>() {
-					public Iterator<Map.Entry<K,V>> iterator() {
-						return new Iterator<Entry<K, V>>(backingMap.entrySet().iterator());
-					}
-					public int size() {
-						return backingMap.size();
-					}
-				};
-			}
-		}
-	}
-	
-}