Spring Framework example source code file (XmlViewResolver.java)

This example Spring Framework source code file (XmlViewResolver.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 - Spring Framework tags/keywords

beanfactory, beanfactory, beansexception, beansexception, disposablebean, genericwebapplicationcontext, genericwebapplicationcontext, locale, locale, nosuchbeandefinitionexception, ordered, resource, util, view, xmlbeandefinitionreader

The Spring Framework XmlViewResolver.java source code

/*
 * Copyright 2002-2006 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 org.springframework.web.servlet.view;

import java.util.Locale;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.DisposableBean;
import org.springframework.beans.factory.NoSuchBeanDefinitionException;
import org.springframework.beans.factory.xml.ResourceEntityResolver;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.core.Ordered;
import org.springframework.core.io.Resource;
import org.springframework.web.context.support.GenericWebApplicationContext;
import org.springframework.web.servlet.View;

/**
 * Implementation of ViewResolver that uses bean definitions in an
 * XML file, specified by resource location. The file will typically
 * be located in the WEB-INF directory; default is "/WEB-INF/views.xml".
 *
 * <p>This ViewResolver does not support internationalization.
 * Consider ResourceBundleViewResolver if you need to apply
 * different view resources per locale.
 *
 * <p>Note: This ViewResolver implements the Ordered interface to allow for
 * flexible participation in ViewResolver chaining. For example, some special
 * views could be defined via this ViewResolver (giving it 0 as "order" value),
 * while all remaining views could be resolved by a UrlBasedViewResolver.
 *
 * @author Juergen Hoeller
 * @since 18.06.2003
 * @see org.springframework.context.ApplicationContext#getResource
 * @see ResourceBundleViewResolver
 * @see UrlBasedViewResolver
 */
public class XmlViewResolver extends AbstractCachingViewResolver implements Ordered, DisposableBean {

	/** Default if no other location is supplied */
	public final static String DEFAULT_LOCATION = "/WEB-INF/views.xml";


	private int order = Integer.MAX_VALUE;  // default: same as non-Ordered

	private Resource location;

	private ConfigurableApplicationContext cachedFactory;


	public void setOrder(int order) {
		this.order = order;
	}

	public int getOrder() {
		return order;
	}

	/**
	 * Set the location of the XML file that defines the view beans.
	 * <p>The default is "/WEB-INF/views.xml".
	 * @param location the location of the XML file.
	 */
	public void setLocation(Resource location) {
		this.location = location;
	}

	/**
	 * Pre-initialize the factory from the XML file.
	 * Only effective if caching is enabled.
	 */
	protected void initApplicationContext() throws BeansException {
		if (isCache()) {
			initFactory();
		}
	}


	/**
	 * This implementation returns just the view name,
	 * as XmlViewResolver doesn't support localized resolution.
	 */
	protected Object getCacheKey(String viewName, Locale locale) {
		return viewName;
	}

	protected View loadView(String viewName, Locale locale) throws BeansException {
		BeanFactory factory = initFactory();
		try {
			return (View) factory.getBean(viewName, View.class);
		}
		catch (NoSuchBeanDefinitionException ex) {
			// to allow for ViewResolver chaining
			return null;
		}
	}

	/**
	 * Initialize the view bean factory from the XML file.
	 * Synchronized because of access by parallel threads.
	 * @throws BeansException in case of initialization errors
	 */
	protected synchronized BeanFactory initFactory() throws BeansException {
		if (this.cachedFactory != null) {
			return this.cachedFactory;
		}

		Resource actualLocation = this.location;
		if (actualLocation == null) {
			actualLocation = getApplicationContext().getResource(DEFAULT_LOCATION);
		}

		// Create child ApplicationContext for views.
		GenericWebApplicationContext factory = new GenericWebApplicationContext();
		factory.setParent(getApplicationContext());
		factory.setServletContext(getServletContext());

		// Load XML resource with context-aware entity resolver.
		XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(factory);
		reader.setEntityResolver(new ResourceEntityResolver(getApplicationContext()));
		reader.loadBeanDefinitions(actualLocation);

		factory.refresh();

		if (isCache()) {
			this.cachedFactory = factory;
		}
		return factory;
	}


	/**
	 * Close the view bean factory on context shutdown.
	 */
	public void destroy() throws BeansException {
		if (this.cachedFactory != null) {
			this.cachedFactory.close();
		}
	}

}