云课堂项目总结（1）

spring加载配置文件时，会自动调用ApplicationContextAware中的setApplicationContext，所以我们可以实现一个工具类继ApplicationContextAware并重写setApplicationContext 获取applicationContext 保存到工具类中，通过注解@Component 或其他 将工具类bean交给spring管理创建。这以后我们就能够方便在我们想要的地方通过applicationContext 获取想要的bean了。
项目当中的工具类：

@Component
public class ApplicationContextHolder implements ApplicationContextAware {
    private static ApplicationContext applicationContext;

    //@Override
    public void setApplicationContext(ApplicationContext ctx) throws BeansException {
        applicationContext = ctx;
    }

    
    public static ApplicationContext getApplicationContext() {
        return applicationContext;
    }

    
    public static  T getBean(Class clazz) {
        return applicationContext.getBean(clazz);
    }

    
    @SuppressWarnings("unchecked")
    public static  T getBean(String name) {
        return (T) applicationContext.getBean(name);
    }
  }

ApplicationContextAware接口：

//
// Source code recreated from a .class file by IntelliJ IDEA
// (powered by Fernflower decompiler)
//

package org.springframework.context;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.Aware;

public interface ApplicationContextAware extends Aware {
    void setApplicationContext(ApplicationContext var1) throws BeansException;
}