获取spring容器中的bean实例

矫情吗；* 2024-03-02 08:02 54阅读 0赞

在开发过程中，我们可能需要动态获取spring容器中的某个bean的实例，此时我们就会用到ApplicationContext spring应用上下文，这里做一下记录，网上很多类似的的工具类。  
  
先写好工具类再测试一下是否好用

工具类：

package com.zhh.demo.common.util;
    
    import org.springframework.beans.BeansException;
    import org.springframework.context.ApplicationContext;
    import org.springframework.context.ApplicationContextAware;
    import org.springframework.stereotype.Component;
    
    /**
     * 容器应用上下文工具类
     * @author zhaoheng
     */
    @Component
    public class ApplicationContextUtil implements ApplicationContextAware {
    
        private static ApplicationContext applicationContext;
    
        /**
         * 将注入的 ApplicationContext 赋值给当前类中的applicationContext
         * @param applicationContext
         * @throws BeansException
         */
        @Override
        public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {
            ApplicationContextUtil.applicationContext = applicationContext;
        }
    
        /**
         * 获取Spring的应用上下文
         * @return
         */
        public static ApplicationContext getContext(){
            return applicationContext;
        }
    
        /**
         * 根据bean名称获取到容器中的bean
         * */
        public static Object getBean(String name) {
            return applicationContext.getBean(name);
        }
    
        /**
         * 根据bean类型获取bean
         * */
        public static <T> T getBean(Class<T> clazz){
            return applicationContext.getBean(clazz);
        }
    
        /**
         * 根据bean类型和名称获取bean
         * */
        public static <T> T getBean(String name, Class<T> requiredType) {
            return applicationContext.getBean(name, requiredType);
        }
    
    }

测试是否好用

创建一个bean并注入到容器

package com.zhh.demo.service;
    
    import org.springframework.stereotype.Service;
    /**
     * @Description: 测试bean
     * @Author: zhaoheng
     */
    @Service
    public class TestService {
        public void show(){
            System.out.println("TestService-show...");
        }
    }

测试方法

package com.zhh.demo;
    
    import com.zhh.demo.common.util.ApplicationContextUtil;
    import com.zhh.demo.service.TestService;
    import org.junit.jupiter.api.Test;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    
    @SpringBootTest
    class ApplicationTest {
        @Autowired
        private ApplicationContextUtil applicationContextUtil;
    
        @Test
        void contextTest() {
            // 通过名称获取容器中的bean
            TestService userService1 = (TestService) applicationContextUtil.getBean("testService");
            userService1.show();
            System.out.println("---------------");
            // 通过class获取容器中的bean
            TestService testService2 = applicationContextUtil.getBean(TestService.class);
            testService2.show();
        }
    }

测试结果：

![d8c1d3a254354bf1a980e5a376928580.png][]

[d8c1d3a254354bf1a980e5a376928580.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/03/02/e1acda82cf6243f4aec8123729964324.png