Index: src/java/org/apache/commons/chain/CatalogFactory.java
===================================================================
RCS file: /home/cvs/jakarta-commons/chain/src/java/org/apache/commons/chain/CatalogFactory.java,v
retrieving revision 1.5
diff -u -d -b -w -u -r1.5 CatalogFactory.java
--- src/java/org/apache/commons/chain/CatalogFactory.java	30 Nov 2004 05:52:22 -0000	1.5
+++ src/java/org/apache/commons/chain/CatalogFactory.java	29 Dec 2004 22:30:33 -0000
@@ -26,6 +26,10 @@
  * as well as {@link Catalog}s stored with a name key.  Follows the
  * Factory pattern (see GoF).</p>
  *
+ * <p>The base <code>CatalogFactory</code> implementation also implements 
+ * a resolution mechanism which allows lookup of a command based on a single string
+ * which encodes both the catalog and command names.</p>
+ *
  * @author Sean Schofield
  * @version $Revision: 1.5 $ $Date: 2004/11/30 05:52:22 $
  */
@@ -80,7 +84,49 @@
      */
     public abstract Iterator getNames();
 
+    /**
+     * <p>Return a <code>Command</code> based on the given ID.</p>
+     * <p>At this time, the structure of the ID is relatively simple:  If the
+     * ID contains a colon (:) character, treat the segment of the ID
+     * up to (but not including) the colon as the name of a catalog, and the 
+     * segment following the colon as a command name within that catalog.  If the 
+     * given ID contains no colon, treat the ID as the name of a command in 
+     * the default catalog. If the catalog identifier cannot be resolved, then the
+     * original parameter is used to lookup a command in the default catalog.</p>
+     * <p>To preserve the possibility of future extensions to this lookup mechanism,
+     * the colon character should be considered reserved, and should not be used in 
+     * command names.</p>
+     * 
+     * @param commandID the identifier of the command to return.
+     */
+    public Command getCommand(String commandID) {
+
+        String commandName = commandID;
+        String catalogName = null;
+        Catalog catalog = null;
+
+        if (commandID != null) {
+            int splitPos = commandID.indexOf(":");
+            if (splitPos != -1) {
+                catalogName = commandID.substring(0, splitPos);
+                commandName = commandID.substring(splitPos + 1);
+            }
+        }
+
+        if (catalogName != null) {
+            catalog = this.getCatalog(catalogName);
 
+            if (catalog == null) { 
+                catalog = this.getCatalog();
+                commandName = commandID;
+            }
+
+        } else {
+            catalog = this.getCatalog();
+        }
+
+        return catalog.getCommand(commandName);
+    }
     // ------------------------------------------------------- Static Variables
 
 
Index: src/test/org/apache/commons/chain/impl/CatalogFactoryBaseTestCase.java
===================================================================
RCS file: /home/cvs/jakarta-commons/chain/src/test/org/apache/commons/chain/impl/CatalogFactoryBaseTestCase.java,v
retrieving revision 1.3
diff -u -d -b -w -u -r1.3 CatalogFactoryBaseTestCase.java
--- src/test/org/apache/commons/chain/impl/CatalogFactoryBaseTestCase.java	9 Dec 2004 05:23:14 -0000	1.3
+++ src/test/org/apache/commons/chain/impl/CatalogFactoryBaseTestCase.java	29 Dec 2004 22:30:33 -0000
@@ -131,6 +131,40 @@
 
     }
 
+    public void testCatalogIdentifier() {
+
+        Catalog defaultCatalog = new CatalogBase();
+        Command defaultFoo = new NonDelegatingCommand();
+        defaultCatalog.addCommand("foo", defaultFoo);
+        Command fallback = new NonDelegatingCommand();
+        defaultCatalog.addCommand("noSuchCatalog:fallback", fallback);
+
+        factory.setCatalog(defaultCatalog);
+
+        Catalog specificCatalog = new CatalogBase();
+        Command specificFoo = new NonDelegatingCommand();
+        specificCatalog.addCommand("foo", specificFoo);
+        factory.addCatalog("specific", specificCatalog);
+
+        Command command = factory.getCommand("foo");
+        assertSame(defaultFoo, command);
+        
+        command = factory.getCommand("specific:foo");
+        assertSame(specificFoo, command);
+
+        command = factory.getCommand("void");
+        assertNull(command);
+
+        command = factory.getCommand("foo:void");
+        assertNull(command);
+
+        command = factory.getCommand("specific:void");
+        assertNull(command);
+
+        command = factory.getCommand("noSuchCatalog:fallback");
+        assertSame(fallback, command);
+        
+    }
 
     // ------------------------------------------------------- Support Methods