SpringObjectFactory

package com.opensymphony.xwork2.spring;

import com.opensymphony.xwork2.ObjectFactory;
import com.opensymphony.xwork2.inject.Inject;
import com.opensymphony.xwork2.util.logging.Logger;
import com.opensymphony.xwork2.util.logging.LoggerFactory;
import org.springframework.beans.BeansException;
import org.springframework.beans.factory.UnsatisfiedDependencyException;
import org.springframework.beans.factory.config.AutowireCapableBeanFactory;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.context.ConfigurableApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

import java.util.HashMap;
import java.util.Map;

/**
 * Simple implementation of the ObjectFactory that makes use of Spring's application context if one has been configured,
 * before falling back on the default mechanism of instantiating a new class using the class name. <p/> In order to use
 * this class in your application, you will need to instantiate a copy of this class and set it as XWork's ObjectFactory
 * before the xwork.xml file is parsed. In a servlet environment, this could be done using a ServletContextListener.
 *
 * @author Simon Stewart (sms@lateral.net)
 */
public class SpringObjectFactory extends ObjectFactory implements ApplicationContextAware {
    private static final Logger LOG = LoggerFactory.getLogger(SpringObjectFactory.class);

    protected ApplicationContext appContext;
    protected AutowireCapableBeanFactory autoWiringFactory;
    protected int autowireStrategy = AutowireCapableBeanFactory.AUTOWIRE_BY_NAME;
    private final Map<String, Object> classes = new HashMap<String, Object>();
    private boolean useClassCache = true;
    private boolean alwaysRespectAutowireStrategy = false;

   
    public Object buildBean(String beanName, Map<String, Object> extraContext, boolean injectInternal) throws Exception {
        Object o;
        //检查Spring容器中是否有该bean，如果有就获取该bean，
        //appContext.getBean()方法会负责 创建或取出该bean
        if (appContext.containsBean(beanName)) {
            o = appContext.getBean(beanName);
        } else {//如果spring容器中没有，就自己创建
            Class beanClazz = getClassInstance(beanName);
            o = buildBean(beanClazz, extraContext);
        }
        //如果该bean需要注入，就通过
        //com.opensymphony.xwork2.inject.Container.inject()注入该bean
        if (injectInternal) {
            injectInternalBeans(o);
        }
        return o;
    }