在網上看到的教程和資料大多數都是2.X以下的版本。使用起來會出現各種問題，通過百度，最後終於弄好了。

2.x以上使用的是

spring-boot-starter-data-redis   
2.x一下使用的是

spring-boot-starter-redis

    <!-- https://mvnrepository.com/artifact/org.springframework.boot/spring-boot-starter-data-redis -->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <version>2.1
 
.3.RELEASE</version>
        </dependency>

package com.chaoba.webapi.cache;
import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.beans.factory.annotation.Value;
 
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.cache.RedisCacheWriter;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.connection.jedis.JedisConnectionFactory;
import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.RedisSerializationContext;
import org.springframework.data.redis.serializer.RedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.lang.reflect.Method;
import java.time.Duration;


/**
 * by chaoba
 * 2019/3/8
 */
@EnableCaching
@Configuration
public class CacheConfig extends CachingConfigurerSupport {

    @Value("${spring.redis.host}")
    private String host;

    @Value("${spring.redis.port}")
    private int port;

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        LettuceConnectionFactory factory = new LettuceConnectionFactory();

        factory.setHostName(host);
        factory.setPort(port);
        factory.setPassword("123456");
        return factory;
    }

    @Bean
    public CacheManager cacheManager(RedisTemplate<Object, Object> redisTemplate,RedisConnectionFactory factory) {
        redisTemplate.setConnectionFactory(factory);

        // 使用Jackson2JsonRedisSerialize 替換默認序列化
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

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

        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);

        // 設置value的序列化規則和 key的序列化規則
        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.afterPropertiesSet();
        RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig()
                .entryTtl(Duration.ofSeconds(3600)); // 設置緩存有效期
        RedisCacheManager cacheManager = RedisCacheManager.builder(factory).cacheDefaults(config).build();

        return cacheManager;
    }

//    @Bean
//    public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
//        RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();
//        redisTemplate.setConnectionFactory(redisConnectionFactory);
//
//        // 使用Jackson2JsonRedisSerialize 替換默認序列化
//        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
//
//        ObjectMapper objectMapper = new ObjectMapper();
//        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
//        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
//
//        jackson2JsonRedisSerializer.setObjectMapper(objectMapper);
//
//        // 設置value的序列化規則和 key的序列化規則
//        redisTemplate.setValueSerializer(jackson2JsonRedisSerializer);
//        redisTemplate.setKeySerializer(new StringRedisSerializer());
//        redisTemplate.afterPropertiesSet();
//        return redisTemplate;
//    }
    /**
     * 自定義的緩存key生成器
     * @return
     */
    @Bean
    public KeyGenerator wiselyKeyGenerator() {
        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();
            }
        };
    }
}

java.util.LinkedHashMap cannot be cast to com.chaoba.webapi.entity.User"
期間出過這個錯誤。我也不知道咋回事。把

RedisTemplate裏面的內容寫到

CacheManager 裏面就沒這個錯誤了。頭疼。還有就是實體要實現序列化接口

SpringBoot 2.X以上集成redis