SpringBoot2.X整合Redis

一、使用Spring Initializr创建项目web项目

1、File→New→Project

2、点击Next如图所示，命名好Group和Artifact
3、Next后如图所示，勾选中需要的依赖，Spring Initializr会自动导入所需的starter
4、创建项目成功后，pom.xml文件中的依赖如下

<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>4.0.0modelVersion>
	<parent>
		<groupId>org.springframework.bootgroupId>
		<artifactId>spring-boot-starter-parentartifactId>
		<version>2.2.2.RELEASEversion>
		<relativePath/> 
	parent>
	<groupId>com.henygroupId>
	<artifactId>spring-boot-redisartifactId>
	<version>0.0.1-SNAPSHOTversion>
	<name>spring-boot-redisname>
	<description>Demo project for Spring Bootdescription>

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

	<dependencies>
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-webartifactId>
		dependency>
		<dependency>
			<groupId>org.mybatis.spring.bootgroupId>
			<artifactId>mybatis-spring-boot-starterartifactId>
			<version>2.1.1version>
		dependency>

		<dependency>
			<groupId>mysqlgroupId>
			<artifactId>mysql-connector-javaartifactId>
			<scope>runtimescope>
		dependency>
		<dependency>
			<groupId>org.springframework.bootgroupId>
			<artifactId>spring-boot-starter-testartifactId>
			<scope>testscope>
			<exclusions>
				<exclusion>
					<groupId>org.junit.vintagegroupId>
					<artifactId>junit-vintage-engineartifactId>
				exclusion>
			exclusions>
		dependency>
	dependencies>

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

project>

5、在pom.xml文件中添加redis的starter

	<dependency>
		<groupId>org.springframework.bootgroupId>
		<artifactId>spring-boot-starter-data-redisartifactId>
	dependency>

6、创建JavaBean用于封装数据库数据，需要实现Serializable

package com.henya.springboot.bean;

import java.io.Serializable;

public class Employee implements Serializable{
	
	private Integer id;
	private String lastName;
	private String email;
	private Integer gender; //性别 1男  0女
	private Integer dId;
	
	
	public Employee() {
		super();
	}

	
	public Employee(Integer id, String lastName, String email, Integer gender, Integer dId) {
		super();
		this.id = id;
		this.lastName = lastName;
		this.email = email;
		this.gender = gender;
		this.dId = dId;
	}
	
	public Integer getId() {
		return id;
	}
	public void setId(Integer id) {
		this.id = id;
	}
	public String getLastName() {
		return lastName;
	}
	public void setLastName(String lastName) {
		this.lastName = lastName;
	}
	public String getEmail() {
		return email;
	}
	public void setEmail(String email) {
		this.email = email;
	}
	public Integer getGender() {
		return gender;
	}
	public void setGender(Integer gender) {
		this.gender = gender;
	}
	public Integer getdId() {
		return dId;
	}
	public void setdId(Integer dId) {
		this.dId = dId;
	}
	@Override
	public String toString() {
		return "Employee [id=" + id + ", lastName=" + lastName + ", email=" + email + ", gender=" + gender + ", dId="
				+ dId + "]";
	}
}

注意：
在写JavaBean对象时需要实现Serializable接口否则会报以下错误：

Cannot deserialize; nested exception is org.springframework.core.serializer.support.SerializationFailedException

7、整合Mybatis操作数据库，在application.properties配置文件中配置数据源信息

#serverTimezone用于指定时区，不然会报错
spring.datasource.url=jdbc:mysql://localhost:3306/cache?serverTimezone=UTC
spring.datasource.username=root
spring.datasource.password=123456

# 开启驼峰命名法规则
mybatis.configuration.map-underscore-to-camel-case=true
#日志级别
logging.level.com.henya.springboot.mapper=debug

8、使用注解版Mybatis创建Mapper

package com.henya.springboot.mapper;


import com.henya.springboot.bean.Employee;
import org.apache.ibatis.annotations.*;

@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 emlpoyee WHERE id=#{id}")
    public void delEmpById(Integer id);

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

    @Select("SELECT * FROM employee WHERE lastName=#{lastName}")
    public Employee getEmpByLastName(String lastName);
}

注意：
需要使用使用@MapperScan注解扫描Mapper所在的接口，只需要加在主程序类上即可。除此之外，还要使用@EnableCaching用于开启缓存。

@MapperScan("com.henya.springboot.mapper")
@SpringBootApplication
@EnableCaching //开启缓存
public class SpringBootRedisApplication {

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

9、编写Service类，用于访问数据库或redis缓存

package com.henya.springboot.service;
import com.henya.springboot.bean.Employee;
import com.henya.springboot.mapper.EmployeeMapper;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cache.annotation.*;
import org.springframework.stereotype.Service;

@CacheConfig(cacheNames = "emp") //抽取缓存的公共配置
@Service
public class EmployeeService {
    @Autowired
    EmployeeMapper employeeMapper;

    /**
     *  @param id
     * @return
     */
    @Cacheable(cacheNames = {"emp"},keyGenerator = "myKeyGenerator")
    public Employee getEmpById(Integer id) {
        System.err.println("开始查询"+ id +"号员工");
        Employee employee = employeeMapper.getEmpById(id);
        return employee;
    }

    /**
     * @CachePut：既调用方法（这个方法必须要执行），又更新缓存数据
     * @param employee
     * @return
     */
    @CachePut(value = "emp",key = "#result.id")
    public Employee updateEmp(Employee employee){
        System.err.println("开始更新" + employee.getId() + "号员工");
        employeeMapper.updateEmp(employee);
        return employee;
    }

    /**
     * @CacheEvict：缓存清除
     * @param id
     */
    @CacheEvict(value = "emp",beforeInvocation = true)
    public void deleteEmp(Integer id){
        System.err.println("删除" + id + "员工");
        int i = 10/0;
    }

10、编写Controller类

package com.henya.springboot.controller;


import com.henya.springboot.bean.Employee;
import com.henya.springboot.service.EmployeeService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;

/**
 * @Description:
 * @Author：HenYa
 * @CreatTime：2019/12/1 12:44
 */
@RestController
public class EmployeeController {
    @Autowired
    EmployeeService employeeService;

    @GetMapping("/emp/{id}")
    public Employee getEmpById(@PathVariable("id") Integer id){
        Employee employee = employeeService.getEmpById(id);
        return employee;
    }

    @GetMapping("/emp")
    public Employee updateEmp(Employee employee){
        Employee emp = employeeService.updateEmp(employee);
        return emp;
    }
}

二、测试SpringBoot整合Redis是否成功

1、在浏览器访问，也可以使用测试类，笔者使用了浏览器访问http://localhost:8080/emp/1进行测试，初次访问时，控制台会提示开始查询1号员工，如图所示。
2、再次访问时，控制台并没有sql日志，如图所示。
3、此时使用RedisDesktopManager工具查看redis时有数据，并且cacheName为emp，如图所示
只是emp对象被序列化了。查看源码可知Redis默认使用Jdk进行序列化。

static RedisSerializer<Object> java(@Nullable ClassLoader classLoader) {
        return new JdkSerializationRedisSerializer(classLoader);
    }

查看RedisSerializer接口的实现有以下几种：

我们常用的就是以json的格式进行序列化。但是需要自定义RedisCacheManager。

三、自定义RedisCacheManager

package com.henya.springboot.config;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.cache.RedisCacheConfiguration;
import org.springframework.data.redis.cache.RedisCacheManager;
import org.springframework.data.redis.cache.RedisCacheWriter;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;

/**
 * @Description:
 * @Author：HenYa
 * @CreatTime：2019/12/6 20:50
 */
@Configuration
public class MyRedisConfig {
    @Bean
    public RedisCacheManager empCacheManager(RedisConnectionFactory redisConnectionFactory){
        //RedisCacheManager redisCacheManager = new RedisCacheManager(redisConnectionFactory);
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory);

        RedisSerializer<Object> redisSerializer = new GenericJackson2JsonRedisSerializer();

        RedisSerializationContext.SerializationPair<Object> pair = RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer);
        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig().serializeValuesWith(pair);
        // 默认会将CacheName作为key的前缀
        return  new RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
    }
    }

此时，Redis中缓存数据就以Json的格式进行序列化，如图所示。