springboot整合Redis

springboot整合Redis

导入redis的依赖

<dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-data-redis</artifactId>
    </dependency>
    <dependency>
        <groupId>redis.clients</groupId>
        <artifactId>jedis</artifactId>
    </dependency>

配置application.yml

spring:
  redis:
    database: 0
    host: 192.168.241.132
    port: 6379
    password: 123456
    jedis:
      pool:
        max-active: 100
        max-idle: 3
        max-wait: -1
        min-idle: 0
    timeout: 1000

创建一个配置类RedisConfig

继承CachingConfigurerSupport，为了自定义生成KEY的策略。可以不继承

package com.liuwenwu.springboot02.config;

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.cache.CacheManager;
import org.springframework.cache.annotation.CachingConfigurerSupport;
import org.springframework.cache.annotation.EnableCaching;
import org.springframework.cache.interceptor.KeyGenerator;
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.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.lang.reflect.Method;
import java.time.Duration;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;

/**
 * redis配置类
 **/
@Configuration
@EnableCaching//开启注解式缓存
//继承CachingConfigurerSupport，为了自定义生成KEY的策略。可以不继承。
public class RedisConfig extends CachingConfigurerSupport {

    /**
     * 生成key的策略 根据类名+方法名+所有参数的值生成唯一的一个key
     *
     * @return
     */
    @Bean
    @Override
    public KeyGenerator keyGenerator() {
        return new KeyGenerator() {
            @Override
            public Object generate(Object target, Method method, Object... params) {
                StringBuilder sb = new StringBuilder();
                sb.append(target.getClass().getName());
                sb.append(method.getName());
                for (Object obj : params) {
                    sb.append(obj.toString());
                }
                return sb.toString();
            }
        };
    }

    /**
     * 管理缓存
     *
     * @param redisConnectionFactory
     * @return
     */
    @Bean
    public CacheManager cacheManager(RedisConnectionFactory redisConnectionFactory) {
        //通过Spring提供的RedisCacheConfiguration类，构造一个自己的redis配置类，从该配置类中可以设置一些初始化的缓存命名空间
        // 及对应的默认过期时间等属性，再利用RedisCacheManager中的builder.build()的方式生成cacheManager：
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig();  // 生成一个默认配置，通过config对象即可对缓存进行自定义配置
        config = config.entryTtl(Duration.ofMinutes(1))     // 设置缓存的默认过期时间，也是使用Duration设置
                .disableCachingNullValues();     // 不缓存空值

        // 设置一个初始化的缓存空间set集合
        Set<String> cacheNames = new HashSet<>();
        cacheNames.add("my-redis-cache1");
        cacheNames.add("my-redis-cache2");

        // 对每个缓存空间应用不同的配置
        Map<String, RedisCacheConfiguration> configMap = new HashMap<>();
        configMap.put("my-redis-cache1", config);
        configMap.put("my-redis-cache2", config.entryTtl(Duration.ofSeconds(120)));

        RedisCacheManager cacheManager = RedisCacheManager.builder(redisConnectionFactory)     // 使用自定义的缓存配置初始化一个cacheManager
                .initialCacheNames(cacheNames)  // 注意这两句的调用顺序，一定要先调用该方法设置初始化的缓存名，再初始化相关的配置
                .withInitialCacheConfigurations(configMap)
                .build();
        return cacheManager;
    }

    @Bean
    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory connectionFactory) {
        RedisTemplate<Object, Object> template = new RedisTemplate<>();
        template.setConnectionFactory(connectionFactory);

        //使用Jackson2JsonRedisSerializer来序列化和反序列化redis的value值（默认使用JDK的序列化方式）
        Jackson2JsonRedisSerializer serializer = new Jackson2JsonRedisSerializer(Object.class);

        ObjectMapper mapper = new ObjectMapper();
        mapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        mapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(mapper);

        template.setValueSerializer(serializer);
        //使用StringRedisSerializer来序列化和反序列化redis的key值
        template.setKeySerializer(new StringRedisSerializer());
        template.afterPropertiesSet();
        return template;
    }

    @Bean
    public StringRedisTemplate stringRedisTemplate(RedisConnectionFactory factory) {
        StringRedisTemplate stringRedisTemplate = new StringRedisTemplate();
        stringRedisTemplate.setConnectionFactory(factory);
        return stringRedisTemplate;
    }

}

SpringBoot整合redis及其注解式开发

常用缓存注解

@Cacheable：作用是主要针对方法配置，能够根据方法的请求参数对其结果进行缓存 

主要参数说明： 

  1) value ： 

  缓存的名称，在 spring 配置文件中定义，必须指定至少一个，

  例如：@Cacheable(value=”mycache”) 或者 @Cacheable(value={”cache1”,”cache2”}。

  2) key ：缓存的 key，可以为空，

  如果指定要按照 SpEL 表达式编写，如果不指定，则缺省按照方法的所有参数进行组合，

  例如：@Cacheable(value=”testcache”,key=”#userName”)。 

  3) condition ：缓存的条件，可以为空，

案例如下：

service层

package com.liuwenwu.springboot02.service;

import com.liuwenwu.springboot02.entity.Book;
import com.liuwenwu.springboot02.util.PageBean;
import org.springframework.cache.annotation.CacheEvict;
import org.springframework.cache.annotation.Cacheable;

import java.util.List;
import java.util.Map;

/**
 * @author LWW
 * @site www.lww.com
 * @company
 * @create 2019-11-09 11:04
 */
public interface BookService {

    int deleteByPrimaryKey(Integer bid);

    @Cacheable(value = "my-redis-cache1",key = "'book'+#bid",condition = "#bid<20")
    Book selectByPrimaryKey(Integer bid);

    @CacheEvict(value = "my-redis-cache1",allEntries = true)
    void clear();


    List<Map> bookPager(Map map, PageBean pageBean);

}

BookServiceImpl

package com.liuwenwu.springboot02.service.impl;

import com.liuwenwu.springboot02.entity.Book;
import com.liuwenwu.springboot02.mapper.BookMapper;
import com.liuwenwu.springboot02.service.BookService;
import com.liuwenwu.springboot02.util.PageBean;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import java.util.List;
import java.util.Map;

/**
 * @author LWW
 * @site www.lww.com
 * @company
 * @create 2019-11-09 11:05
 */
@Service
public class BookServiceImpl implements BookService {

    @Autowired
    private BookMapper bookMapper;

    @Override
    public int deleteByPrimaryKey(Integer bid) {
        return bookMapper.deleteByPrimaryKey(bid);
    }

    @Override
    public Book selectByPrimaryKey(Integer bid) {
        return bookMapper.selectByPrimaryKey(bid);
    }

    @Override
    public void clear() {
        System.out.println("此处不需要代码");
    }

    @Override
    public List<Map> bookPager(Map map, PageBean pageBean) {
        return bookMapper.bookPager(map);
    }
}

测试代码

@Test
    public void selectCacheByPrimaryKey(){
        Book book = bookService.selectByPrimaryKey(17);
        System.out.println(book);

        Book book2 = bookService.selectByPrimaryKey(17);
        System.out.println(book2);

        Book book3 = bookService.selectByPrimaryKey(33);
        System.out.println(book3);

        Book book4 = bookService.selectByPrimaryKey(33);
        System.out.println(book4);
    }

@CacheEvict：作用是主要针对方法配置，能够根据一定的条件对缓存进行清空 

  

  主要参数说明：

  1）value ， key 和 condition 参数配置和@Cacheable一样。

  2) allEntries ：

  是否清空所有缓存内容，缺省为 false，

  如果指定为 true，则方法调用后将立即清空所有缓存，

  例如：@CachEvict(value=”testcache”,allEntries=true)。

service层代码

  @CacheEvict(value = "my-redis-cache1",allEntries = true)
    void clear();

测试代码如下

  @Test
    public void clear(){
        this.bookService.clear();
    }