SpringBoot 與緩存
一、概念
JSR-107、Spring緩存抽象、整合Redis
jsr107 太復雜,用Spring緩存抽象,既有自己的緩存管理器,也可以引用jsr
幾個重要概念&緩存注解
Cache | 緩存接口,定義緩存操作。實現有:RedisCache、EhCacheCache |
---|---|
CacheManager | 緩存管理器,管理各種緩存(Cache)組件 |
@Cacheable | 主要針對方法配置,能夠根據方法的請求參數對其結果進行緩存 |
@CacheEvict | 情況緩存 |
@CachePut | 保證方法被調用,又希望結果被緩存 |
@EnabelCaching | 開啟基於注解的緩存 |
keyGenerator | 緩存數據是key生成策略 |
serialize | 緩存數據時value序列化策略 |
二、Springboot-cache Demo
1.新建一個springboot 項目
項目結構
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;
/**
* 搭建基本環境
* 1.導入數據庫文件 創建出department和employer表
* 2.創建javebean封裝數據
* 3.整合MyBatis操作數據庫
* 1)配置數據源信息
* 2)使用注解版的MyBatis
* *@MapperScan指定需要掃描的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 快捷鍵 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);
}
}
錯誤&修復
錯誤描述
java.sql.SQLException: The server time zone value '�й���ʱ��' 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.
原因及解決方法
原因是使用了Mysql Connector/J 6.x以上的版本,然后就報了時區的錯誤,解決方法:
方法1.
在配置url的時候不能簡單寫成 :
jdbc:mysql://localhost:3306/test
而是要寫成 :
jdbc:mysql://localhost:3306/test?serverTimezone=UTC
方法2.更改mysql connector版本
這里修改為:
spring.datasource.url=jdbc:mysql://localhost:3306/spring-cache?serverTimezone=UTC
測試成功