一、通過指定配置文件獲取， 對於Web程序而言，我們啟動spring容器是通過在web.xml文件中配置，這樣相當於加載了兩次spring容器

ApplicationContext ac = new FileSystemXmlApplicationContext("applicationContext.xml");
ac.getBean("beanId"); 

二、通過Spring提供的工具類獲取ApplicationContext對象

ApplicationContext ac1 = WebApplicationContextUtils.getRequiredWebApplicationContext(request.getSession().getServletContext());
ApplicationContext ac2 
 
= WebApplicationContextUtils.getWebApplicationContext(request.getSession().getServletContext());
MyService service1 = (MyService)ac1.getBean("bean1");//這是beanId. 
MyService service2 = (MyService)ac2.getBean("bean2");

　　這種方式明顯有很大的漏洞，其一：需要request對象，其二：很難封裝一個Java工具類

三、實現接口ApplicationContextAware， 或繼承實現ApplicationContextAware接口的類

package com.zxguan;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ApplicationObjectSupport;

/**
 * @author zxguan
 * @description
 * @create 2018-01-29 14:54
 */
public class SpringTool extends ApplicationObjectSupport {

    
 
private static ApplicationContext applicationContext = null;

    @Override
    protected void initApplicationContext(ApplicationContext context) throws BeansException {
        super.initApplicationContext(context);
        if (null == SpringTool.applicationContext) {
            SpringTool.applicationContext = context;
        }
    }

    public static ApplicationContext getAppContext() {
        return applicationContext;
    }

    public static Object getBean(String beanId){
        return getAppContext().getBean(beanId);
    }
}

　　還需將類 SpringTool 交由 Spring容器管理

Spring 自定義Bean 實例獲取