后端开发总是要保证数据返回的速度越快越好，可是数据库查问就是那么个速度，通过优化SQL和数据库配置都不是最正当的办法。所以明天咱们来看一下缓存。

Cache

话说缓存，咱们总是第一工夫想到redis，可是最要害的是redis须要本人启动客户端，这就比拟麻烦了。咱们只是须要缓存简略的数据怎么办？springboot为咱们想到了这个问题，于是默认增加了缓存ConcurrentMapCacheManager。

1. 新建SpringBoot我的项目

不再赘述，参考之前的文章即可

2. 批改pom.xml文件

<dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-data-jpa</artifactId></dependency><dependency>    <groupId>mysql</groupId>    <artifactId>mysql-connector-java</artifactId></dependency><dependency>    <groupId>org.springframework.boot</groupId>    <artifactId>spring-boot-starter-web</artifactId></dependency>

这里咱们应用jpa。

3. 新建数据库表

DROP TABLE IF EXISTS `user`;CREATE TABLE `user`  (  `id` int NOT NULL AUTO_INCREMENT,  `name` varchar(64) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL COMMENT '姓名',  `address` varchar(512) CHARACTER SET utf8 COLLATE utf8_bin NULL DEFAULT NULL COMMENT '地址',  `age` int NULL DEFAULT NULL COMMENT '年龄',  PRIMARY KEY (`id`) USING BTREE) ENGINE = InnoDB CHARACTER SET = utf8 COLLATE = utf8_bin ROW_FORMAT = Dynamic;SET FOREIGN_KEY_CHECKS = 1;

4. 写代码啦

4.1 新建实体类User

/** * 实体类 * @author zhouzhaodong */@Entitypublic class User implements Serializable {    @Id    @GeneratedValue(strategy= GenerationType.IDENTITY)    private int id;    private String name;    private String address;    private int age;    public int getId() {        return id;    }    public void setId(int id) {        this.id = id;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public String getAddress() {        return address;    }    public void setAddress(String address) {        this.address = address;    }    public int getAge() {        return age;    }    public void setAge(int age) {        this.age = age;    }    @Override    public String toString() {        return "User{" +                "id=" + id +                ", name='" + name + '\'' +                ", address='" + address + '\'' +                ", age=" + age +                '}';    }}

4.2 新建数据库拜访层继承JpaRepository

/** * 数据库拜访层 * @author zhouzhaodong */public interface UserRepository extends JpaRepository<User, Integer> {    /**     * 依据id更新     *     * @param id     * @param name     * @param address     * @param age     */    @Modifying    @Query(value = "update user u set u.name = :name, u.address = :address, u.age = :age  where u.id = :id", nativeQuery = true)    User updateById(@Param("id") Integer id,                    @Param("name") String name,                    @Param("address") String address,                    @Param("age") int age);}

4.3 定义业务层类

/** * Service * @author zhouzhaodong */@Servicepublic interface UserService {    /**     * 新增     * @param user     * @return     */    User insert(User user);    /**     * 删除     * @param id     * @return     */    void delete(int id);    /**     * 更新     * @param user     * @return     */    void update(User user);    /**     * 依据id查问     * @param id     * @return     */    Object findById(int id);}
/** * 实现类 * @author zhouzhaodong */@Servicepublic class UserServiceImpl implements UserService {    @Resource    UserRepository userRepository;    @Override    @CachePut(value = "user", key = "#result.id")    public User insert(User user) {        return userRepository.save(user);    }    @Override    @CacheEvict(value = "user", key = "#id")    public void delete(int id) {        userRepository.deleteById(id);    }    @Override    @CachePut(value = "user", key = "#user.id")    public User update(User user) {        return userRepository.updateById(user.getId(), user.getName(), user.getAddress(), user.getAge());    }    @Override    @Cacheable(value = "user", key = "#id")    public Object findById(int id) {        return userRepository.findById(id);    }}

4.4 管制层

/** * 管制层 * @author zhouzhaodong */@RestControllerpublic class UserController {    @Resource    UserService userService;    @RequestMapping("/save")    public User saveUser(User user){        return userService.insert(user);    }    @RequestMapping("/delete")    public void deleteUser(int id){        userService.delete(id);    }    @RequestMapping("/update")    public User updateUser(User user){        return userService.update(user);    }    @RequestMapping("/find")    public Object findById(int id){        return userService.findById(id);    }}

4.5 启动类增加注解

/** * 启动类 * @author zhouzhaodong */@SpringBootApplication@EnableCachingpublic class CacheApplication {    public static void main(String[] args) {        SpringApplication.run(CacheApplication.class, args);    }}

4.6 application配置文件

server:  port: 8989 # 端口号spring:  datasource:    url: jdbc:mysql://ip地址:3306/test?characterEncoding=utf8&useSSL=false&serverTimezone=GMT%2b8&rewriteBatchedStatements=true    username: 用户名    password: 明码  jpa:    show-sql: true # 打印sql    properties:      hibernate:        format_sql: true # 打印sql

5. post测试

首先新增数据，而后进行查问就会发现并不走数据库查问，控制台不打印sql，缓存胜利。

具体代码请查看：

https://github.com/zhouzhaodo...

集体博客：

http://www.zhouzhaodong.xyz/