/*

  * Copyright 2002-2009 the original author or authors.

  *

  * Licensed 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 net.sf.json.util;

 import java.lang.reflect.Constructor;

 import java.lang.reflect.InvocationTargetException;

 import net.sf.json.JSONObject;

 /**

  * Base class for creating Bean instances.<br>

  * <ul>

  * <li>DEFAULT - calls Class.newInstance().</li>

  * </ul>

  *

  * @author Andres Almiray <aalmiray@users.sourceforge.net>

  */

 public abstract class NewBeanInstanceStrategy {

    /** Calls Class.newInstance() */

    public static final NewBeanInstanceStrategy DEFAULT = new DefaultNewBeanInstanceStrategy();

    /**

     * Creates a new instance.

     *

     * @param target the source class

     * @param source additional properties that may be needed to create the

     *        instance

     */

    public abstract Object newInstance( Class target, JSONObject source )

          throws InstantiationException, IllegalAccessException, SecurityException,

          NoSuchMethodException, InvocationTargetException;

    private static final class DefaultNewBeanInstanceStrategy extends NewBeanInstanceStrategy {

       private static final Object[] EMPTY_ARGS = new Object[0];

       private static final Class[] EMPTY_PARAM_TYPES = new Class[0];

       public Object newInstance( Class target, JSONObject source ) throws InstantiationException,

             IllegalAccessException, SecurityException, NoSuchMethodException,

             InvocationTargetException {

          if( target != null ){

             Constructor c = target.getDeclaredConstructor( EMPTY_PARAM_TYPES );

             c.setAccessible( true );

             try {

                return c.newInstance( EMPTY_ARGS );

             } catch ( InstantiationException e ) {

                // getCause() was added on jdk 1.4

                String cause = "";

                try { cause = e.getCause() != null ? "\n"+e.getCause().getMessage() : ""; }

                catch( Throwable t ) { /* ignore */ }

                throw new InstantiationException(

                      "Instantiation of \"" +  target + "\" failed. " +

                      "It's probably because class is an interface, " +

                      "abstract class, array class, primitive type or void." +

                      cause );

             }

          }

          return null;

       }

    }

 }