com.googlecode.openbeans.ClassPersistenceDelegate Maven / Gradle / Ivy

Go to download
Show more of this group Show more artifacts with this name
Show all versions of app55-java Show documentation
App55 client library for the Java platform.
The newest version!
/*
 *  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 com.googlecode.openbeans;

import java.lang.reflect.Field;

class ClassPersistenceDelegate extends PersistenceDelegate
{
	@Override
	protected Expression instantiate(Object oldInstance, Encoder out)
	{
		Class value = (Class) oldInstance;
		Field fld = null;
		final String TYPE = "TYPE"; //$NON-NLS-1$
		Expression result;
		/*
		 * Special treatment to String.class to prevent endless loop of instantiation.
		 */
		if (value == String.class)
		{
			return new Expression(value, "", "getClass", null); //$NON-NLS-1$//$NON-NLS-2$
		}
		try
		{
			if (value.equals(Integer.TYPE))
			{
				fld = Integer.class.getField(TYPE);
			}
			else if (value.equals(Short.TYPE))
			{
				fld = Short.class.getField(TYPE);
			}
			else if (value.equals(Long.TYPE))
			{
				fld = Long.class.getField(TYPE);
			}
			else if (value.equals(Float.TYPE))
			{
				fld = Float.class.getField(TYPE);
			}
			else if (value.equals(Double.TYPE))
			{
				fld = Double.class.getField(TYPE);
			}
			else if (value.equals(Byte.TYPE))
			{
				fld = Byte.class.getField(TYPE);
			}
			else if (value.equals(Character.TYPE))
			{
				fld = Character.class.getField(TYPE);
			}
			else if (value.equals(Boolean.TYPE))
			{
				fld = Boolean.class.getField(TYPE);
			}
		}
		catch (NoSuchFieldException e)
		{
			// impossible situation for valid java.lang classes
			// implementation with version >= 1.1
			throw new AssertionError(e);
		}
		if (fld != null)
		{
			// we have primitive type
			result = new Expression(oldInstance, fld, "get", new Object[] { null }); //$NON-NLS-1$
		}
		else
		{
			result = new Expression(oldInstance, String.class, "forName", //$NON-NLS-1$ 
					new Object[] { value.getName() });
		}
		return result;
	}

	@Override
	/*
	 * It's unnecessary to do anything for initialization, because two mutatable class objects are actually the same.
	 */
	protected void initialize(Class type, Object oldInstance, Object newInstance, Encoder out)
	{
		// do nothing
	}

	@Override
	protected boolean mutatesTo(Object oldInstance, Object newInstance)
	{
		if (oldInstance instanceof Class && newInstance instanceof Class)
		{
			Class c1 = (Class) oldInstance;
			Class c2 = (Class) newInstance;
			if (c1.getName().equals(c2.getName()))
			{
				return true;
			}
			return false;
		}
		return super.mutatesTo(oldInstance, newInstance);
	}
}