Hibernate example source code file (DirectPropertyAccessor.java)

This example Hibernate source code file (DirectPropertyAccessor.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Hibernate tags/keywords

class, class, directgetter, directsetter, field, field, getter, object, propertyaccessexception, propertynotfoundexception, propertynotfoundexception, reflection, setter, string, string, util

The Hibernate DirectPropertyAccessor.java source code

/*
 * Hibernate, Relational Persistence for Idiomatic Java
 *
 * Copyright (c) 2009 by Red Hat Inc and/or its affiliates or by
 * third-party contributors as indicated by either @author tags or express
 * copyright attribution statements applied by the authors.  All
 * third-party contributions are distributed under license by Red Hat Inc.
 *
 * This copyrighted material is made available to anyone wishing to use, modify,
 * copy, or redistribute it subject to the terms and conditions of the GNU
 * Lesser General Public License, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
 * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License
 * for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with this distribution; if not, write to:
 * Free Software Foundation, Inc.
 * 51 Franklin Street, Fifth Floor
 * Boston, MA  02110-1301  USA
 */
package org.hibernate.property;
import java.lang.reflect.Field;
import java.lang.reflect.Member;
import java.lang.reflect.Method;
import java.util.Map;
import org.hibernate.HibernateException;
import org.hibernate.PropertyAccessException;
import org.hibernate.PropertyNotFoundException;
import org.hibernate.engine.spi.SessionFactoryImplementor;
import org.hibernate.engine.spi.SessionImplementor;
import org.hibernate.internal.util.ReflectHelper;

/**
 * Accesses fields directly.
 * @author Gavin King
 */
public class DirectPropertyAccessor implements PropertyAccessor {

	public static final class DirectGetter implements Getter {
		private final transient Field field;
		private final Class clazz;
		private final String name;
		DirectGetter(Field field, Class clazz, String name) {
			this.field = field;
			this.clazz = clazz;
			this.name = name;
		}

		/**
		 * {@inheritDoc}
		 */
		public Object get(Object target) throws HibernateException {
			try {
				return field.get(target);
			}
			catch (Exception e) {
				throw new PropertyAccessException(e, "could not get a field value by reflection", false, clazz, name);
			}
		}

		/**
		 * {@inheritDoc}
		 */
		public Object getForInsert(Object target, Map mergeMap, SessionImplementor session) {
			return get( target );
		}

		/**
		 * {@inheritDoc}
		 */
		public Member getMember() {
			return field;
		}

		/**
		 * {@inheritDoc}
		 */
		public Method getMethod() {
			return null;
		}

		/**
		 * {@inheritDoc}
		 */
		public String getMethodName() {
			return null;
		}

		/**
		 * {@inheritDoc}
		 */
		public Class getReturnType() {
			return field.getType();
		}

		Object readResolve() {
			return new DirectGetter( getField(clazz, name), clazz, name );
		}
		
		public String toString() {
			return "DirectGetter(" + clazz.getName() + '.' + name + ')';
		}
	}

	public static final class DirectSetter implements Setter {
		private final transient Field field;
		private final Class clazz;
		private final String name;
		DirectSetter(Field field, Class clazz, String name) {
			this.field = field;
			this.clazz = clazz;
			this.name = name;
		}

		/**
		 * {@inheritDoc}
		 */
		public Method getMethod() {
			return null;
		}

		/**
		 * {@inheritDoc}
		 */
		public String getMethodName() {
			return null;
		}

		/**
		 * {@inheritDoc}
		 */
		public void set(Object target, Object value, SessionFactoryImplementor factory) throws HibernateException {
			try {
				field.set(target, value);
			}
			catch (Exception e) {
				if(value == null && field.getType().isPrimitive()) {
					throw new PropertyAccessException(
							e, 
							"Null value was assigned to a property of primitive type", 
							true, 
							clazz, 
							name
						);					
				} else {
					throw new PropertyAccessException(e, "could not set a field value by reflection", true, clazz, name);
				}
			}
		}

		public String toString() {
			return "DirectSetter(" + clazz.getName() + '.' + name + ')';
		}
		
		Object readResolve() {
			return new DirectSetter( getField(clazz, name), clazz, name );
		}
	}

	private static Field getField(Class clazz, String name) throws PropertyNotFoundException {
		if ( clazz==null || clazz==Object.class ) {
			throw new PropertyNotFoundException("field not found: " + name); 
		}
		Field field;
		try {
			field = clazz.getDeclaredField(name);
		}
		catch (NoSuchFieldException nsfe) {
			field = getField( clazz, clazz.getSuperclass(), name );
		}
		if ( !ReflectHelper.isPublic(clazz, field) ) field.setAccessible(true);
		return field;
	}

	private static Field getField(Class root, Class clazz, String name) throws PropertyNotFoundException {
		if ( clazz==null || clazz==Object.class ) {
			throw new PropertyNotFoundException("field [" + name + "] not found on " + root.getName()); 
		}
		Field field;
		try {
			field = clazz.getDeclaredField(name);
		}
		catch (NoSuchFieldException nsfe) {
			field = getField( root, clazz.getSuperclass(), name );
		}
		if ( !ReflectHelper.isPublic(clazz, field) ) field.setAccessible(true);
		return field;
	}
	
	public Getter getGetter(Class theClass, String propertyName)
		throws PropertyNotFoundException {
		return new DirectGetter( getField(theClass, propertyName), theClass, propertyName );
	}

	public Setter getSetter(Class theClass, String propertyName)
		throws PropertyNotFoundException {
		return new DirectSetter( getField(theClass, propertyName), theClass, propertyName );
	}

}