SpringBoot 与缓存

一、概念

JSR-107、Spring缓存抽象、整合Redis

jsr107 太复杂，用Spring缓存抽象，既有自己的缓存管理器，也可以引用jsr

? 几个重要概念&缓存注解

二、Springboot-cache Demo

1.新建一个springboot 项目

项目结构

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 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.7.RELEASE</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>cn.cmdzz</groupId>
    <artifactId>springboot-01-cache</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>springboot-01-cache</name>
    <description>Demo project for Spring Boot</description>

    <properties>
        <java.version>1.8</java.version>
    </properties>

    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
            <version>2.1.2</version>
        </dependency>

        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <scope>runtime</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

application.properties

spring.datasource.url=jdbc:mysql://localhost:3306/spring-cache
spring.datasource.username=root
spring.datasource.password=123456
#spring.datasource.driver-class-name=com.mysql.jdbc.Driver

SpringBootCacheApplication.java

package cn.cmdzz;

import org.mybatis.spring.annotation.MapperScan;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;

/**
 * 搭建基本环境
 * 1.导入数据库文件 创建出department和employer表
 * 2.创建javebean封装数据
 * 3.整合MyBatis操作数据库
 *      1）配置数据源信息
 *      2）使用注解版的MyBatis
 *          *@MapperScan指定需要扫描的mapper接口所在的包
 *
 *
 */
@MapperScan("cn.cmdzz.mapper")
@SpringBootApplication
public class Springboot01CacheApplication {

    public static void main(String[] args) {
        SpringApplication.run(Springboot01CacheApplication.class, args);
    }

}

bean

Department.java

package cn.cmdzz.bean;

/**
 * @author cmdzhizhu  @date 2020/5/15 16:19
 */
public class Department {

    private Integer id;
    private String departmentName;


 //get/set等省略

Employee.java

package cn.cmdzz.bean;

/**
 * @author cmdzhizhu  @date 2020/5/14 20:59
 */
//get set 快捷键 alt+insert
public class Employee {
    private Integer id;
    private String lastName;
    private String email;
    private Integer gender;
    private Integer dId;


//get set 等省略

mapper

EmployeeMapper.java

package cn.cmdzz.mapper;

import cn.cmdzz.bean.Employee;
import org.apache.ibatis.annotations.*;

/**
 * @author cmdzhizhu  @date 2020/5/15 16:30
 */
@Mapper
public interface EmployeeMapper {

    @Select("SELECT * FROM employee WHERE id = #{id}")
    public Employee getEmpById(Integer id);

    @Update("UPDATE employee SET lastName = #{lastName},email = #{email},gender=#{gender},d_id=#{dId} WHERE id=#{id}")
    public void updateEmp(Employee employee);

    @Delete("DELETE FROM employee WHERE id=#{id}")
    public void deleteEmpById(Integer id);

    @Insert("INSERT INTO employee(lastName,email,gender,d_id) VALUES(#{lastName},#{email},#{gender},#{dId}")
    public void insertEmployee(Employee employee);
}

Test

Springboot01CacheApplicationTests.java

package cn.cmdzz;

import cn.cmdzz.bean.Employee;
import cn.cmdzz.mapper.EmployeeMapper;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
class Springboot01CacheApplicationTests {

    @Autowired
    EmployeeMapper employeeMapper;

    @Test
    void contextLoads() {
        Employee employee = employeeMapper.getEmpById(1);
        System.out.println(employee);
    }

}

错误&修复

错误描述

java.sql.SQLException: The server time zone value ‘?й???????‘ is unrecognized or represents more than one time zone. You must configure either the server or JDBC driver (via the ‘serverTimezone‘ configuration property) to use a more specifc time zone value if you want to utilize time zone support.

原因及解决方法

原因是使用了Mysql Connector/J 6.x以上的版本，然后就报了时区的错误，解决方法：
    方法1.
    在配置url的时候不能简单写成 ：
    jdbc:mysql://localhost:3306/test
    而是要写成 ：
    jdbc:mysql://localhost:3306/test?serverTimezone=UTC
    方法2.更改mysql connector版本

这里修改为：

spring.datasource.url=jdbc:mysql://localhost:3306/spring-cache?serverTimezone=UTC

测试成功

SpingBoot 错误 java.sql.SQLException: The server time zone value '?й???????' is unrecognized or represents more than one time zone...