content: /**
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *   http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  package org.apache.aries.samples.blog.biz;
  
  import java.lang.reflect.Constructor;
  import java.util.ListIterator;
  
  public class BlogListIterator<B, F> implements ListIterator<F> {
  
  	private ListIterator<? extends B> internalListIterator;
  
  	private Class<? extends F> frontendClazz;
  	private Class<B> backendClazz;
  
  	public BlogListIterator(ListIterator<? extends B> listIterator,
  			Class<? extends F> frontendClazz, Class<B> backendClazz) {
  		this.internalListIterator = listIterator;
  		this.frontendClazz = frontendClazz;
  		this.backendClazz = backendClazz;
  	}
  
  	public void add(Object e) {
  		throw new UnsupportedOperationException("");
  	}
  
  	public boolean hasNext() {
  		return internalListIterator.hasNext();
  	}
  
  	public boolean hasPrevious() {
  		return internalListIterator.hasPrevious();
  	}
  
  	public F next() {
  		try {
  			return getConstructor().newInstance(internalListIterator.next());
  		} catch (Exception e) {
  			// TODO Auto-generated catch block
  			e.printStackTrace();
  		}
  		return null;
  	}
  
  	public int nextIndex() {
  		return internalListIterator.nextIndex();
  	}
  
  	public F previous() {	
  		try {
  			return getConstructor().newInstance(internalListIterator.previous());
  		} catch (Exception e) {
  			// TODO Auto-generated catch block
  			e.printStackTrace();
  		}
  		return null;
  	}
  
  	public int previousIndex() {
  		// TODO Auto-generated method stub
  		return 0;
  	}
  
  	public void remove() {
  		throw new UnsupportedOperationException(
  				"Modifications to the list are not supported");
  	}
  
  	public void set(Object e) {
  		throw new UnsupportedOperationException(
  				"Modifications to the list are not supported");
  	}
  
  	private Constructor<F> getConstructor() {
  		Constructor<F> c;
  		try {
  			c = (Constructor<F>) frontendClazz.getConstructor(backendClazz);
  			return c;
  		} catch (Exception e) {
  			// TODO Auto-generated catch block
  			e.printStackTrace();
  		}
  		return null;
  	}
  }
  