SpringBoot自学好几天 中途开始写笔记 SpringBoot与缓存 JRS-107 SpringBoot缓存抽象 整合Redis 20190227

一、搭建redis环境 docker

1. 下载镜像 可以用镜像加速（https://www.docker-cn.com/registry-mirror）

	docker pull registry.docker-cn.com/library/镜像
	例如：	docker pull registry.docker-cn.com/library/redis 

2. docker images 查看镜像

3. 启动

docker run -d -p 6379:6379 --name myredis  registry.docker-cn.com/library/redis

4. 测试RedisDesktopManager
   
5. 简单测试redis常用操作
   点击console 会出现命令框
   
   
   存入数据：
   
   list测试
   
   set测试
   

redis连接

二、缓存RedisTemplete 序列化机制

1. 引入redis的sstarter点击查看地址
   
2. pom.xml

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

引入之后redis自动配置类就起作用了

@Configuration
@ConditionalOnClass({RedisOperations.class})
@EnableConfigurationProperties({RedisProperties.class})
@Import({LettuceConnectionConfiguration.class, JedisConnectionConfiguration.class})
public class RedisAutoConfiguration {

自动配置文件给容器中添加了两个操作redis的方法

@Configuration
@ConditionalOnClass({RedisOperations.class})
@EnableConfigurationProperties({RedisProperties.class})
@Import({LettuceConnectionConfiguration.class, JedisConnectionConfiguration.class})
public class RedisAutoConfiguration {
    public RedisAutoConfiguration() {
    }

    @Bean
    @ConditionalOnMissingBean(
        name = {"redisTemplate"}
    )
    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        RedisTemplate<Object, Object> template = new RedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }

    @Bean
    @ConditionalOnMissingBean
    public StringRedisTemplate stringRedisTemplate(RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        StringRedisTemplate template = new StringRedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        return template;
    }
}

3. 配置redis

spring.redis.host=192.168.2.118

4. 测试

    @Autowired
    RedisTemplate redisTemplate;//操作对象

    @Autowired
    StringRedisTemplate stringRedisTemplate;//操作字符串


    /**redis常见的五大数据类型
     * String(字符串)  List(列表) Set(集合) Hash(散列) ZSet(有序集合)
     */
    @Test
    public void contextLoads() {
        //redis保存数据
        stringRedisTemplate.opsForValue().append("msg","你好啊");
    }

测试list

  @Test
    public void contextLoads() {
        //redis保存数据
        //stringRedisTemplate.opsForValue().append("msg","你好啊");
        //String msg  = stringRedisTemplate.opsForValue().get("msg");
        //System.out.println(msg); //输出结果：你好啊
        stringRedisTemplate.opsForList().leftPush("mylist","1");
        stringRedisTemplate.opsForList().leftPush("mylist","2");
        stringRedisTemplate.opsForList().leftPush("mylist","3");
        //命令行的操作 这里几乎都能用！！！
    }

测试存储对象

package com.example.cache.bean;

import java.io.Serializable;

/**
 * @author LM
 * @create 2019-02-25 20:51
 * 对象要实现 implements 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 + "]";
    }



}

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootCacheApplicationTests {

    @Autowired
    RedisTemplate redisTemplate;//操作对象

    @Autowired
    StringRedisTemplate stringRedisTemplate;//操作字符串

    @Autowired
    EmployeeMapper employeeMapper ;



    @Test
    public void testObj(){
        Employee e = employeeMapper.getEmpById(1);
        redisTemplate.opsForValue().set("emp-01",e);
    }

}

太乱不好 想用json格式保存？？？

1. 自己将数据转换成json格式
2. redisTemplete默认序列化规则 用的就是JDK的序列化器 换成json的就行了

package com.example.cache.config;

import com.example.cache.bean.Employee;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;

import java.net.UnknownHostException;

/**
 * @author LM
 * @create 2019-02-27 21:29
 */
@Configuration //配置类
public class MyRedisTemplete {

    @Bean //写自己的序列化
    public RedisTemplate<Object, Employee> empRedisTemplate(RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        RedisTemplate<Object, Employee> template = new RedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        //自定义序列化器
        Jackson2JsonRedisSerializer<Employee> serializer = new Jackson2JsonRedisSerializer<Employee>(Employee.class);
        template.setDefaultSerializer(serializer);
        return template;
    }
}

测试自定义RedisTemplete

package com.example.cache;

import com.example.cache.bean.Employee;
import com.example.cache.mapper.EmployeeMapper;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.test.context.junit4.SpringRunner;

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootCacheApplicationTests {

    @Autowired
    RedisTemplate redisTemplate;//操作对象

    @Autowired
    StringRedisTemplate stringRedisTemplate;//操作字符串

    @Autowired
    EmployeeMapper employeeMapper ;

    @Autowired
    RedisTemplate<Object, Employee> empRedisTemplate;

    @Test
    public void testObj(){
        Employee e = employeeMapper.getEmpById(1);
        empRedisTemplate.opsForValue().set("emp-01",e);
    }

}

三、缓存 自定义CacheManager

原理：CacheManager 创建 Cache ，Cache 组件实际给缓存中存取数据

1. 引入redis的starter的时候 容器中保存的是RedisCacheManager
2. RedisCacheManager 帮我们创建RedisCache作为缓存组件 RedisCache操作redis数据
3. 默认保存数据k-v 都是对象的时候 利用序列化来保存的 如何保存json???
4. 自定义CacheManager

package com.example.cache.config;

import com.example.cache.bean.Employee;
import org.springframework.cache.CacheManager;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.core.io.ResourceLoader;
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.core.RedisTemplate;
import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;

import java.net.UnknownHostException;
import java.time.Duration;
import java.util.LinkedHashSet;
import java.util.List;

/**
 * @author LM
 * @create 2019-02-27 21:29
 */
@Configuration
public class MyRedisTemplete {

    @Bean
    public RedisTemplate<Object, Employee> empRedisTemplate(RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        RedisTemplate<Object, Employee> template = new RedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        //自定义序列化器
        Jackson2JsonRedisSerializer<Employee> serializer = new Jackson2JsonRedisSerializer<Employee>(Employee.class);
        template.setDefaultSerializer(serializer);
        return template;
    }

    /**
     * 自定义redis缓存管理器
     */
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
        //初始化一个RedisCacheWriter
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory);
        //设置CacheManager的值序列化方式为json序列化
        RedisSerializer<Object> jsonSerializer = new GenericJackson2JsonRedisSerializer();
        RedisSerializationContext.SerializationPair<Object> pair = RedisSerializationContext.SerializationPair
                .fromSerializer(jsonSerializer);
        RedisCacheConfiguration defaultCacheConfig=RedisCacheConfiguration.defaultCacheConfig()
                .serializeValuesWith(pair);
        //设置默认超过期时间是30秒
        defaultCacheConfig.entryTtl(Duration.ofSeconds(30));
        //初始化RedisCacheManager
        return new RedisCacheManager(redisCacheWriter, defaultCacheConfig);
    }

}

缓存结果：

1.0版本是不一样的 1.0需要每个实体定义一个CacheManager 然后在缓存的时候类上或者是方法上指定使用哪个 cacheManager，而且还要指定默认的cacheManager (@Primary)

注：我们还可以使用api 直接在代码里获取Cache 然后进行数据操作