Use factories implemented as nested classes (rather than reflected constructors) to store classes to instantiate.

Now every subclass of TodoElement or TodoAttr should also come with a
nested subclass of TodoElement.Factory or TodoAttr.Factory which just
contains a(n instance) method to call its constructor.  In essecne,
the factory instance is just used as a pointer to the class to create
(or its constructor, as in the previous version).

1 files changed, 14 insertions, 23 deletions

diff --git a/org/madore/damlengine/TodoAttr.java b/org/madore/damlengine/TodoAttr.java
index 2b3df23..721b4f6 100644
--- a/org/madore/damlengine/TodoAttr.java
+++ b/org/madore/damlengine/TodoAttr.java
@@ -1,7 +1,5 @@
 package org.madore.damlengine;
 
-import java.lang.reflect.Constructor;
-import java.lang.reflect.InvocationTargetException;
 import java.util.Map;
 import java.util.HashMap;
 import org.w3c.dom.Element;
@@ -9,16 +7,17 @@ import org.w3c.dom.Attr;
 
 public abstract class TodoAttr extends TodoItem {
 
-    protected static Map<String,Constructor<? extends TodoAttr>> damlAttrConstructors;
+    public static abstract class Factory {
+	public abstract TodoAttr newItem(Attr attr, Element owner,
+					 Map<String,Object> context,
+					 Map<String,Object> options);
+    }
+
+    protected static Map<String,Factory> damlAttrFactories;
 
     static {
-	damlAttrConstructors = new HashMap<String,Constructor<? extends TodoAttr>>();
-	Class[] argTypes = new Class[]{ Attr.class, Element.class, Map.class, Map.class };
-	try {
-	    damlAttrConstructors.put("xempty", TodoXemptyAttr.class.getConstructor(argTypes));
-	} catch (NoSuchMethodException e) {
-	    // FIXME: Do something intelligent here!
-	}
+	damlAttrFactories = new HashMap<String,Factory>();
+	damlAttrFactories.put("xempty", new TodoXemptyAttr.Factory());
     }
 
     Attr attr;
@@ -37,21 +36,13 @@ public abstract class TodoAttr extends TodoItem {
     public static TodoAttr getTodoAttr(Attr attr, Element owner,
 				       Map<String,Object> context,
 				       Map<String,Object> options) {
-	Constructor<? extends TodoAttr> constructor = null;
+	Factory factory = null;
 	String nsuri = attr.getNamespaceURI();
 	if ( nsuri != null && nsuri.equals(DamlEngine.DAML_NS) )
-	    constructor = damlAttrConstructors.get(attr.getLocalName());
-	if ( constructor != null )
-	    try {
-		return constructor.newInstance(new Object[]{attr, owner, context, options});
-	    } catch (InstantiationException e) {
-		// FIXME: Do something intelligent here!
-	    } catch (IllegalAccessException e) {
-		// FIXME: Do something intelligent here!
-	    } catch (InvocationTargetException e) {
-		// FIXME: Do something intelligent here!
-	    }
-	return null;
+	    factory = damlAttrFactories.get(attr.getLocalName());
+	if ( factory == null )
+	    return null;
+	return factory.newItem(attr, owner, context, options);
     }
 
 }