Spring环境获取Spring的Bean

一、测试数据准备

/*
 Navicat Premium Data Transfer

 Source Server         : swp-mysql
 Source Server Type    : MySQL
 Source Server Version : 50730
 Source Host           : localhost:3306
 Source Schema         : project

 Target Server Type    : MySQL
 Target Server Version : 50730
 File Encoding         : 65001

 Date: 24/07/2022 23:56:58
*/

SET NAMES utf8mb4;
SET FOREIGN_KEY_CHECKS = 0;

-- ----------------------------
-- Table structure for employee
-- ----------------------------
DROP TABLE IF EXISTS `employee`;
CREATE TABLE `employee`  (
  `id` int(5) NOT NULL,
  `name` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  `email` varchar(255) CHARACTER SET utf8mb4 COLLATE utf8mb4_general_ci NULL DEFAULT NULL,
  `age` int(3) NULL DEFAULT NULL,
  `dept_id` int(5) NULL DEFAULT NULL,
  PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_general_ci ROW_FORMAT = Dynamic;

-- ----------------------------
-- Records of employee
-- ----------------------------
INSERT INTO `employee` VALUES (1, '张三', 'zhangsan@qq.com', 28, 101);
INSERT INTO `employee` VALUES (2, '王五', 'wangwu@qq.com', 24, 102);

SET FOREIGN_KEY_CHECKS = 1;

二、SpringContextUtil编写工具类

编写的工具类为SpringUtil，实现ApplicationContextAware接口，并加入Component注解，让spring扫描到该bean：

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import org.springframework.beans.BeansException; import org.springframework.context.ApplicationContext; import org.springframework.context.ApplicationContextAware; import org.springframework.stereotype.Component; import org.springframework.web.context.request.RequestContextHolder; import org.springframework.web.context.request.ServletRequestAttributes;   import javax.servlet.http.HttpServletRequest;   @Component public class SpringContextUtil implements ApplicationContextAware {       /**      * 上下文对象实例      */     private static ApplicationContext applicationContext;       @Override     public void setApplicationContext(ApplicationContext applicationContext) throws BeansException {         this.applicationContext = applicationContext;     }       /**      * 获取applicationContext      *      * @return      */     public static ApplicationContext getApplicationContext() {         return applicationContext;     }       /**      * 获取HttpServletRequest      */     public static HttpServletRequest getHttpServletRequest() {         return ((ServletRequestAttributes) RequestContextHolder.getRequestAttributes()).getRequest();     }       public static String getDomain(){         HttpServletRequest request = getHttpServletRequest();         StringBuffer url = request.getRequestURL();         return url.delete(url.length() - request.getRequestURI().length(), url.length()).toString();     }       public static String getOrigin(){         HttpServletRequest request = getHttpServletRequest();         return request.getHeader("Origin");     }       /**      * 通过name获取 Bean.      *      * @param name      * @return      */     public static Object getBean(String name) {         return getApplicationContext().getBean(name);     }       /**      * 通过class获取Bean.      *      * @param clazz      * @param       <T>      * @return      */     public static <T> T getBean(Class<T> clazz) {         return getApplicationContext().getBean(clazz);     }       /**      * 通过name,以及Clazz返回指定的Bean      *      * @param name      * @param clazz      * @param       <T>      * @return      */     public static <T> T getBean(String name, Class<T> clazz) {         return getApplicationContext().getBean(name, clazz);     } }

三、SpringContextUtil工具类实例测试

（1）.编写测试的mapper实例：

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/**  * @Project:  * @Description:  * @Auther: songwp  * @Date: 2022/1/30 10:23  **/ @Mapper public interface EmployeeMapper {       List<Employee> findAll();       Employee selectById(Integer id); }

（2）junit单元测试结果如下：

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@Test public void contextLoads(){      EmployeeMapper empService = SpringContextUtil.getBean(EmployeeMapper.class);      System.out.println(empService.findAll());    }