学习笔记 : Spring Boot拥抱MyBatis及Redis ~
Spring Boot集成MyBatis
下面通过使用Spring Boot开发一个基于SSM的框架的应用,并通过一个简单的用户信息查询为例,记录如何在Spring Boot中使用MyBatis ~
tb_user.sql : 用户信息数据表
create table tb_user ( id int auto_increment primary key, name varchar(15) not null, gender char null, email varchar(50) null );pom.xml
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <!-- lookup parent from repository --> <parent> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-parent</artifactId> <version>2.1.6.RELEASE</version> <relativePath/> </parent> <groupId>pers.huangyuhui</groupId> <artifactId>redis</artifactId> <version>0.0.1-SNAPSHOT</version> <name>springboot_redis</name> <description>Demo project for Spring Boot</description> <properties> <java.version>11</java.version> </properties> <dependencies> <!-- Web --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <!-- MyBatis --> <dependency> <groupId>org.mybatis.spring.boot</groupId> <artifactId>mybatis-spring-boot-starter</artifactId> <version>2.0.1</version> </dependency> <!-- Redis --> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency> <!-- MySQL --> <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> </dependencies> <build> <!-- mvn package --> <plugins> <plugin> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-maven-plugin</artifactId> </plugin> </plugins> </build> </project>SpringbootRedisApplication.java : Spring Boot启动类
package pers.huangyuhui.redis; import org.springframework.boot.SpringApplication; import org.springframework.boot.autoconfigure.SpringBootApplication; @SpringBootApplication public class SpringbootRedisApplication { public static void main(String[] args) { SpringApplication.run(SpringbootRedisApplication.class, args); } }application.properties : Spring Boot配置文件
#JDBC-Connection Configuration Information spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver spring.datasource.url=jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC&allowPublicKeyRetrieval=true spring.datasource.username=xxxxxx spring.datasource.password=xxxxxx #Logging Configuration Information logging.level.pers.huangyuhui.redis=debugUser.java : 用户信息实体类
package pers.huangyuhui.redis.bean; /** * @project: springboot_redis * @description: 用户信息 * @author: 黄宇辉 * @date: 7/1/2019-7:08 AM * @version: 1.0 * @website: https://yubuntu0109.github.io/ */ public class User { private Integer id; private String name; private String gender; private String email; //getter and setter ······ }UserMapper.java : 操控用户数据表信息
package pers.huangyuhui.redis.dao; import org.apache.ibatis.annotations.Mapper; import org.apache.ibatis.annotations.Select; import pers.huangyuhui.redis.bean.User; import java.util.List; /** * @project: springboot_redis * @description: Dao层-操控用户信息 * @author: 黄宇辉 * @date: 7/1/2019-7:12 AM * @version: 1.0 * @website: https://yubuntu0109.github.io/ */ @Mapper public interface UserMapper { // TODO: 7/1/2019 查询所有用户信息 @Select("select * from tb_user") List<User> selectAll(); // TODO: 7/1/2019 根据id删除指定用户信息 @Delete("Delete from tb_user where id = #{id}") void deleteById(Integer id); }UserService.java : 操控用户信息
package pers.huangyuhui.redis.service; import pers.huangyuhui.redis.bean.User; import java.util.List; /** * @project: springboot_redis * @description: Service层-操控用户信息 * @author: 黄宇辉 * @date: 7/1/2019-7:25 AM * @version: 1.0 * @website: https://yubuntu0109.github.io/ */ public interface UserService { // TODO: 7/1/2019 获取或有用户信息 List<User> findAll(); // TODO: 7/1/2019 根据id删除指定用户信息 void delete(Integer id); }UserServiceImpl.java : UserService.java的实现类
package pers.huangyuhui.redis.service.impl; import org.springframework.stereotype.Service; import org.springframework.transaction.annotation.Transactional; import pers.huangyuhui.redis.bean.User; import pers.huangyuhui.redis.dao.UserMapper; import pers.huangyuhui.redis.service.UserService; import javax.annotation.Resource; import java.util.List; /** * @project: springboot_redis * @description: UserService的实现类 * @author: 黄宇辉 * @date: 7/1/2019-7:27 AM * @version: 1.0 * @website: https://yubuntu0109.github.io/ */ @Service @Transactional public class UserServiceImpl implements UserService { //注入Mapper对象 @Resource private UserMapper userMapper; @Override public List<User> findAll() { return userMapper.selectAll(); } @Override public void delete(Integer id) { userMapper.deleteById(id); } }UserController.java : 用户信息控制器
package pers.huangyuhui.redis.controller; import org.springframework.beans.factory.annotation.Autowired; import org.springframework.stereotype.Controller; import org.springframework.web.bind.annotation.PathVariable; import org.springframework.web.bind.annotation.RequestMapping; import org.springframework.web.bind.annotation.ResponseBody; import pers.huangyuhui.redis.bean.User; import pers.huangyuhui.redis.service.UserService; import java.util.List; /** * @project: springboot_redis * @description: 用户控制器 * @author: 黄宇辉 * @date: 7/1/2019-7:28 AM * @version: 1.0 * @website: https://yubuntu0109.github.io/ */ @Controller @RequestMapping("/user") public class UserController { //注入业务对象 @Autowired private UserService userService; /** * @description: 获取所有用户信息 * @date: 2019-07-01 8:16 AM * @return: java.util.List<pers.huangyuhui.redis.bean.User> */ @RequestMapping("/getUserList") @ResponseBody public List<User> getUserList() { return userService.findAll(); } /** * @description: 删除指定id的好友信息 * @param: id * @date: 2019-07-01 12:51 PM * @return: void */ @RequestMapping("/deleteUser/{id}") public void deleteUser(@PathVariable Integer id) { userService.delete(id); } }userList.html : 用户信息列表页面 (将EasyUI框架的资源文件拷贝到src/main/resource下的static文件夹下,并在static文件夹中创建
userList.html页面文件)<!DOCTYPE html> <html lang="en"> <head> <meta charset="UTF-8"> <title>用户信息列表页面</title> <!-- CSS --> <link rel="stylesheet" type="text/css" href="easyui/themes/metro/easyui.css"/> <!-- JS --> <script type="text/javascript" src="easyui/jquery.min.js"></script> <script type="text/javascript" src="easyui/jquery.easyui.min.js"></script> <script type="text/javascript" src="easyui/themes/locale/easyui-lang-zh_CN.js"></script> <script type="text/javascript"> $(function () { $('#graid').datagrid({ url: 'user/getUserList', fit: true, columns: [[ {field: 'id', title: '编号', width: 100}, {field: 'name', title: '姓名', width: 100}, {field: 'gender', title: '性别', width: 100}, {field: 'email', title: '邮箱', width: 200} ]] }); }); </script> </head> <body> <!-- 用户信息列表 --> <table id="graid"></table> </body> </html>启动Spring Boot项目,在浏览器中输入访问地址 :
http://localhost:8080/userList.html后,显示效果参考下图 :
紧接着刷新页面三次,其控制台打印的日志信息如下所示,发现每刷新一次页面都会执行一次查询数据库操作,但如果将列表数据缓冲到Redis后,会发现控制台只会出现一次查询数据库的日志信息哟 !
2019-07-01 11:41:49.868 DEBUG 7844 --- [nio-8080-exec-3] p.h.redis.dao.UserMapper.selectAll : ==> Preparing: select * from tb_user
2019-07-01 11:41:49.869 DEBUG 7844 --- [nio-8080-exec-3] p.h.redis.dao.UserMapper.selectAll : ==> Parameters:
2019-07-01 11:41:49.871 DEBUG 7844 --- [nio-8080-exec-3] p.h.redis.dao.UserMapper.selectAll : <== Total: 5
2019-07-01 11:41:54.250 DEBUG 7844 --- [nio-8080-exec-5] p.h.redis.dao.UserMapper.selectAll : ==> Preparing: select * from tb_user
2019-07-01 11:41:54.250 DEBUG 7844 --- [nio-8080-exec-5] p.h.redis.dao.UserMapper.selectAll : ==> Parameters:
2019-07-01 11:41:54.253 DEBUG 7844 --- [nio-8080-exec-5] p.h.redis.dao.UserMapper.selectAll : <== Total: 5
2019-07-01 11:41:57.251 DEBUG 7844 --- [nio-8080-exec-7] p.h.redis.dao.UserMapper.selectAll : ==> Preparing: select * from tb_user
2019-07-01 11:41:57.251 DEBUG 7844 --- [nio-8080-exec-7] p.h.redis.dao.UserMapper.selectAll : ==> Parameters:
2019-07-01 11:41:57.256 DEBUG 7844 --- [nio-8080-exec-7] p.h.redis.dao.UserMapper.selectAll : <== Total: 5
Process finished with exit code -1Spring Boot集成Redis
Redis是一个完全开源的,遵守BSD协议的,内存中的数据结构存储,它既可以作为数据库,也可以作为缓存和消息代理. 通常在企业中常将其作为缓存使用哟~ 接下来在Spring Boot集成MyBatis示例程序基础上将列表数据缓存到Redis中,详细步骤如下 :
在
pom.xml中添加Spring Boot支持Redis的依赖<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-data-redis</artifactId> </dependency>在
SpringbootRedisApplication.java中添加@EnableCaching注解来开启缓存@SpringBootApplication @EnableCaching public class SpringbootRedisApplication { //······ }在业务逻辑类
UserServiceImpl.java的方法上添加@Cacheable注解来支持Redis缓存@Override @Cacheable(value = "UserCatch", key = "'user.selectAll'") public List<User> findAll() { return userMapper.selectAll(); }为便于数据的传输,将实体类
User.java实现序列化接口Serializablepublic class User implements Serializable { //······ }在
application.properties中指定Redis缓存主机地址及端口号. 我使用的是Windows的Redis发行版哟,其学习笔记 : https://yubuntu0109.github.io/2019/06/25/Hi-Redis/#Redis Configuration Infromation spring.redis.host=localhost spring.redis.port=6379启动Redis服务,并启动Spring Boot项目,在浏览器地址栏中输入访问地址 :
http://localhost:8080/userList.html后,不断刷新页面,其控制台打印的日志信息如下,结论 : 在没有使用Redis缓存之前,每刷新一次页面,都会执行一次查询数据库的操作,添加缓存后,会发现日志信息中只出现了一次查询语句,这也就说明所配置的Redis缓存已经生效啦 ~2019-07-01 12:43:06.945 INFO 1984 --- [nio-8080-exec-1] o.a.c.c.C.[Tomcat].[localhost].[/] : Initializing Spring DispatcherServlet 'dispatcherServlet' 2019-07-01 12:43:06.946 INFO 1984 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Initializing Servlet 'dispatcherServlet' 2019-07-01 12:43:06.951 INFO 1984 --- [nio-8080-exec-1] o.s.web.servlet.DispatcherServlet : Completed initialization in 5 ms 2019-07-01 12:43:07.218 INFO 1984 --- [nio-8080-exec-7] io.lettuce.core.EpollProvider : Starting without optional epoll library 2019-07-01 12:43:07.218 INFO 1984 --- [nio-8080-exec-7] io.lettuce.core.KqueueProvider : Starting without optional kqueue library 2019-07-01 12:43:07.701 INFO 1984 --- [nio-8080-exec-7] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Starting... 2019-07-01 12:43:07.791 INFO 1984 --- [nio-8080-exec-7] com.zaxxer.hikari.HikariDataSource : HikariPool-1 - Start completed. 2019-07-01 12:43:07.805 DEBUG 1984 --- [nio-8080-exec-7] p.h.redis.dao.UserMapper.selectAll : ==> Preparing: select * from tb_user 2019-07-01 12:43:07.815 DEBUG 1984 --- [nio-8080-exec-7] p.h.redis.dao.UserMapper.selectAll : ==> Parameters: 2019-07-01 12:43:07.836 DEBUG 1984 --- [nio-8080-exec-7] p.h.redis.dao.UserMapper.selectAll : <== Total: 7 Process finished with exit code -1
清除Redis缓存
当执行添加,更新和删除操作后,数据库中的数据会发生变化,继而Redis缓存中的数据同样也需要进行相应的变化,为了保证Redis缓存中的数据与数据库中的一致,通常需要在执行添加,更新和删除操作之前清除缓存,然后再下一次执行查询操作时,将新的数据存储到Redis缓存中 .
若要实现清除缓存的功能,只需在相应的方法中使用@CacheEvict注解即可,下面以案例程序中的删除用户功能为例,在用户业务逻辑类的deleteUser()方法上添加@CacheEvict注解 :
@Override
@CacheEvict(value = "UserCatch", key = "'user.selectAll'")
public void delete(Integer id) {
userMapper.deleteById(id);
}重启Spring Boot项目,在浏览器地址栏中输入访问地址 : http://localhost:8080/user/deleteUser/5, ../6 , ../7删除id为5,6,7的用户信息后再查询用户列表信息 : http://localhost:8080/userList.html,其控制台打印的日志信息如下 :
2019-07-01 18:13:45.143 DEBUG 14764 --- [nio-8080-exec-1] p.h.redis.dao.UserMapper.deleteById : ==> Preparing: Delete from tb_user where id = ?
2019-07-01 18:13:45.160 DEBUG 14764 --- [nio-8080-exec-1] p.h.redis.dao.UserMapper.deleteById : ==> Parameters: 5(Integer)
2019-07-01 18:13:45.162 DEBUG 14764 --- [nio-8080-exec-1] p.h.redis.dao.UserMapper.deleteById : <== Updates: 1
2019-07-01 18:13:45.331 INFO 14764 --- [nio-8080-exec-1] io.lettuce.core.EpollProvider : Starting without optional epoll library
2019-07-01 18:13:45.332 INFO 14764 --- [nio-8080-exec-1] io.lettuce.core.KqueueProvider : Starting without optional kqueue library
2019-07-01 18:15:16.033 DEBUG 14764 --- [nio-8080-exec-4] p.h.redis.dao.UserMapper.deleteById : ==> Preparing: Delete from tb_user where id = ?
2019-07-01 18:15:16.033 DEBUG 14764 --- [nio-8080-exec-4] p.h.redis.dao.UserMapper.deleteById : ==> Parameters: 6(Integer)
2019-07-01 18:15:16.034 DEBUG 14764 --- [nio-8080-exec-4] p.h.redis.dao.UserMapper.deleteById : <== Updates: 1
2019-07-01 18:15:31.217 DEBUG 14764 --- [nio-8080-exec-6] p.h.redis.dao.UserMapper.deleteById : ==> Preparing: Delete from tb_user where id = ?
2019-07-01 18:15:31.218 DEBUG 14764 --- [nio-8080-exec-6] p.h.redis.dao.UserMapper.deleteById : ==> Parameters: 7(Integer)
2019-07-01 18:15:31.219 DEBUG 14764 --- [nio-8080-exec-6] p.h.redis.dao.UserMapper.deleteById : <== Updates: 1
2019-07-01 18:15:47.353 DEBUG 14764 --- [nio-8080-exec-4] p.h.redis.dao.UserMapper.selectAll : ==> Preparing: Select * from tb_user
2019-07-01 18:15:47.353 DEBUG 14764 --- [nio-8080-exec-4] p.h.redis.dao.UserMapper.selectAll : ==> Parameters:
2019-07-01 18:15:47.377 DEBUG 14764 --- [nio-8080-exec-4] p.h.redis.dao.UserMapper.selectAll : <== Total: 4
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