https://github.com/spring-projects/spring-framework: Spring Web (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2012 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
 *
 *      https://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.context.support;

import javax.servlet.ServletContext;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

import org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor;
import org.springframework.util.Assert;
import org.springframework.util.ClassUtils;
import org.springframework.web.context.ContextLoader;
import org.springframework.web.context.WebApplicationContext;


Convenient base class for self-autowiring classes that gets constructed within a Spring-based web application. Resolves @Autowired annotations in the endpoint class against beans in the current Spring root web application context (as determined by the current thread's context ClassLoader, which needs to be the web application's ClassLoader). Can alternatively be used as a delegate instead of as a base class. 
A typical usage of this base class is a JAX-WS endpoint class: Such a Spring-based JAX-WS endpoint implementation will follow the standard JAX-WS contract for endpoint classes but will be 'thin' in that it delegates the actual work to one or more Spring-managed service beans - typically obtained using @Autowired. The lifecycle of such an endpoint instance will be managed by the JAX-WS runtime, hence the need for this base class to provide @Autowired processing based on the current Spring context. 
NOTE: If there is an explicit way to access the ServletContext, prefer such a way over using this class. The WebApplicationContextUtils class allows for easy access to the Spring root web application context based on the ServletContext. 
Author:Juergen Hoeller
See Also:
Since:2.5.1
/**
 * Convenient base class for self-autowiring classes that gets constructed
 * within a Spring-based web application. Resolves {@code @Autowired}
 * annotations in the endpoint class against beans in the current Spring
 * root web application context (as determined by the current thread's
 * context ClassLoader, which needs to be the web application's ClassLoader).
 * Can alternatively be used as a delegate instead of as a base class.
 *
 * <p>A typical usage of this base class is a JAX-WS endpoint class:
 * Such a Spring-based JAX-WS endpoint implementation will follow the
 * standard JAX-WS contract for endpoint classes but will be 'thin'
 * in that it delegates the actual work to one or more Spring-managed
 * service beans - typically obtained using {@code @Autowired}.
 * The lifecycle of such an endpoint instance will be managed by the
 * JAX-WS runtime, hence the need for this base class to provide
 * {@code @Autowired} processing based on the current Spring context.
 *
 * <p><b>NOTE:</b> If there is an explicit way to access the ServletContext,
 * prefer such a way over using this class. The {@link WebApplicationContextUtils}
 * class allows for easy access to the Spring root web application context
 * based on the ServletContext.
 *
 * @author Juergen Hoeller
 * @since 2.5.1
 * @see WebApplicationObjectSupport
 */
public abstract class SpringBeanAutowiringSupport {

	private static final Log logger = LogFactory.getLog(SpringBeanAutowiringSupport.class);


	
This constructor performs injection on this instance,
based on the current web application context.

Intended for use as a base class.

See Also:
  • processInjectionBasedOnCurrentContext
/**
	 * This constructor performs injection on this instance,
	 * based on the current web application context.
	 * <p>Intended for use as a base class.
	 * @see #processInjectionBasedOnCurrentContext
	 */
	public SpringBeanAutowiringSupport() {
		processInjectionBasedOnCurrentContext(this);
	}


	
Process @Autowired injection for the given target object, based on the current web application context. 
Intended for use as a delegate.

Params:
  • target – the target object to process
See Also:
/**
	 * Process {@code @Autowired} injection for the given target object,
	 * based on the current web application context.
	 * <p>Intended for use as a delegate.
	 * @param target the target object to process
	 * @see org.springframework.web.context.ContextLoader#getCurrentWebApplicationContext()
	 */
	public static void processInjectionBasedOnCurrentContext(Object target) {
		Assert.notNull(target, "Target object must not be null");
		WebApplicationContext cc = ContextLoader.getCurrentWebApplicationContext();
		if (cc != null) {
			AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
			bpp.setBeanFactory(cc.getAutowireCapableBeanFactory());
			bpp.processInjection(target);
		}
		else {
			if (logger.isDebugEnabled()) {
				logger.debug("Current WebApplicationContext is not available for processing of " +
						ClassUtils.getShortName(target.getClass()) + ": " +
						"Make sure this class gets constructed in a Spring web application. Proceeding without injection.");
			}
		}
	}


	
Process @Autowired injection for the given target object, based on the current root web application context as stored in the ServletContext. 
Intended for use as a delegate.

Params:
  • target – the target object to process
  • servletContext – the ServletContext to find the Spring web application context in
See Also:
  • WebApplicationContextUtils.getWebApplicationContext(ServletContext)
/**
	 * Process {@code @Autowired} injection for the given target object,
	 * based on the current root web application context as stored in the ServletContext.
	 * <p>Intended for use as a delegate.
	 * @param target the target object to process
	 * @param servletContext the ServletContext to find the Spring web application context in
	 * @see WebApplicationContextUtils#getWebApplicationContext(javax.servlet.ServletContext)
	 */
	public static void processInjectionBasedOnServletContext(Object target, ServletContext servletContext) {
		Assert.notNull(target, "Target object must not be null");
		WebApplicationContext cc = WebApplicationContextUtils.getRequiredWebApplicationContext(servletContext);
		AutowiredAnnotationBeanPostProcessor bpp = new AutowiredAnnotationBeanPostProcessor();
		bpp.setBeanFactory(cc.getAutowireCapableBeanFactory());
		bpp.processInjection(target);
	}

}