net.solarnetwork.node.util.BeanConfigurationFactoryBean.java Source code

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Here is the source code for net.solarnetwork.node.util.BeanConfigurationFactoryBean.java

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/* ==================================================================
 * BeanConfigurationFactoryBean.java - Dec 10, 2009 10:45:34 AM
 * 
 * Copyright 2007-2009 SolarNetwork.net Dev Team
 * 
 * This program is free software; you can redistribute it and/or 
 * modify it under the terms of the GNU General Public License as 
 * published by the Free Software Foundation; either version 2 of 
 * the License, or (at your option) any later version.
 * 
 * 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 
 * General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License 
 * along with this program; if not, write to the Free Software 
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 
 * 02111-1307 USA
 * ==================================================================
 * $Id$
 * ==================================================================
 */

package net.solarnetwork.node.util;

import java.util.Map;

import org.springframework.beans.BeanWrapper;
import org.springframework.beans.PropertyAccessorFactory;
import org.springframework.beans.factory.FactoryBean;

/**
 * {@link FactoryBean} implementation that creates objects based on properties
 * specified on a {@link BeanConfiguration} object.
 * 
 * <p>The configurable properties of this class are:</p>
 * 
 * <dl class="class-properties">
 *   <dt>beanClass</dt>
 *   <dd>The type of object to create when {@link #getObject()} is called.</p>
 *   
 *   <dt>config</dt>
 *   <dd>The {@link BeanConfiguration} to use for configuring the created
 *   object instance. The {@link BeanConfiguration#getConfiguration()} will
 *   be used to configure properties of any created object.</dd>
 *   
 *   <dt>singleton</dt>
 *   <dd>If <em>true</em> (the default) then only ever create one object
 *   instance. Otherwise a new object instance will be created each time
 *   {@link #getObject()} is called.</dd>
 *   
 *   <dt>staticProperties</dt>
 *   <dd>An optional Map of additional properties to configure on the created
 *   object(s). These properties will be applied first if configured, followed
 *   by the {@link BeanConfiguration} properties, so these can serve as default
 *   values if needed.</dd>
 * </dl>
 * 
 * @author matt
 * @version $Id$
 */
public class BeanConfigurationFactoryBean<T> implements FactoryBean<T> {

    private BeanConfiguration config = null;
    private Class<T> beanClass = null;
    private boolean singleton = true;
    private Map<String, ?> staticProperties = null;

    private T singletonObject = null;

    private final Object monitor = new Object();

    public T getObject() throws Exception {
        if (isSingleton()) {
            synchronized (monitor) {
                if (singletonObject == null) {
                    singletonObject = createObject();
                }
                return singletonObject;
            }
        }
        return createObject();
    }

    private T createObject() throws InstantiationException, IllegalAccessException {
        T obj = beanClass.newInstance();
        BeanWrapper wrapper = PropertyAccessorFactory.forBeanPropertyAccess(obj);
        if (this.staticProperties != null) {
            wrapper.setPropertyValues(this.staticProperties);
        }
        wrapper.setPropertyValues(config.getConfiguration());
        return obj;
    }

    public Class<T> getObjectType() {
        return beanClass;
    }

    public boolean isSingleton() {
        return this.singleton;
    }

    /**
     * @return the config
     */
    public BeanConfiguration getConfig() {
        return config;
    }

    /**
     * @param config the config to set
     */
    public void setConfig(BeanConfiguration config) {
        this.config = config;
    }

    /**
     * @return the beanClass
     */
    public Class<?> getBeanClass() {
        return beanClass;
    }

    /**
     * @param beanClass the beanClass to set
     */
    public void setBeanClass(Class<T> beanClass) {
        this.beanClass = beanClass;
    }

    /**
     * @param singleton the singleton to set
     */
    public void setSingleton(boolean singleton) {
        this.singleton = singleton;
    }

    /**
     * @return the staticProperties
     */
    public Map<String, ?> getStaticProperties() {
        return staticProperties;
    }

    /**
     * @param staticProperties the staticProperties to set
     */
    public void setStaticProperties(Map<String, ?> staticProperties) {
        this.staticProperties = staticProperties;
    }

}