Simple DSL for creating GAE Entities

EntityBuilder.java

import com.google.appengine.api.datastore.DatastoreService;
import com.google.appengine.api.datastore.DatastoreServiceFactory;
import com.google.appengine.api.datastore.Entity;
import com.google.appengine.api.datastore.Key;

/**
 * Example (groovy syntax, but works just as well in Java):
 * <pre> 
EntityBuilder.build("Library").
	key(key). // can create your own Key instance
	child("Owner").
		p("books",[123,456]).
		p('name','Joe Blow').
	finish().
	child("Book").
		key(456).
	finish().
	child("Book").
		key(123).
		p('title','Eating Animals')
		child("Chapter").
			p('name','How to serve man').
		finish().
		child("Chapter").
			p('name','How to serve pig').
		finish()
</pre>
 * 
 * @author noah
 *
 */
public class EntityBuilder {

	public class SubEntityBuilder {
	
		public KeyBuilder child(String kind) {
			return new EntityBuilder(kind, EntityBuilder.this).key();
		}		
		
		public SubEntityBuilder finish() {
			return EntityBuilder.this.finish();
		}
	}
	
	public class KeyBuilder {

		public EntityBuilder key(Key key) {
			entity = new Entity(key);
			return EntityBuilder.this;
		}
		
		public EntityBuilder key(long key) {
			entity = parent == null ?
				new Entity(kind, key) :
				new Entity(kind, key, parent.entity.getKey());
			return EntityBuilder.this;
		}
		
		public EntityBuilder name(String name) {
			entity = parent == null ?
					new Entity(kind, name) :
					new Entity(kind, name, parent.entity.getKey());
			return EntityBuilder.this;
		}
		
		public EntityBuilder p(String name, Object value) {
			defaultKey();
			return EntityBuilder.this.p(name, value);
		}

		private void defaultKey() {
			entity = parent == null ? 
				new Entity(EntityBuilder.this.kind) :
				new Entity(kind, parent.entity.getKey());
		}
		
		public KeyBuilder child(String kind) {
			defaultKey();
			return new EntityBuilder(kind, EntityBuilder.this).key();
		}				

	}
	
	private String kind;

	private EntityBuilder(String kind,EntityBuilder parent) {
		super();
		this.datastore = DatastoreServiceFactory.getDatastoreService();
		this.parent = parent;
		this.kind = kind;
	}
	
	public static KeyBuilder build(String kind) {
		return new EntityBuilder(kind,null).key();
	}
	
	private KeyBuilder key() {
		return new KeyBuilder();
	}
	
	private Entity entity;
	private final EntityBuilder parent;
	private final DatastoreService datastore;
	
		
	public EntityBuilder p(String name, Object value) {
		entity.setProperty(name, value);
		return this;
	}
	
	public KeyBuilder child(String kind) {
		finish();
		return new SubEntityBuilder().child(kind);
	}
	
	public SubEntityBuilder finish() {
		datastore.put(entity);
		return parent == null ? null :
			parent.new SubEntityBuilder();
	}
	
}