Redis學習筆記一、使用方式一代碼示例

1、主要介紹兩張不同的使用方法：

package com.haoxiansheng.middleware.springMessage;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.haoxiansheng.middleware.MainApplicationTest;
import com.haoxiansheng.middleware.rabbitmq.entity.User;
import lombok.extern.slf4j.Slf4j;
import org.junit.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ValueOperations;

import java.util.Optional;

@Slf4j
public class RedisTest extends MainApplicationTest {


    @Autowired
    private RedisTemplate redisTemplate;  //配置中自定義注入 在直接自動裝配

    @Autowired
    private ObjectMapper objectMapper;  // 定義JSON 序列化與反序列化框架類

    @Autowired
    private StringRedisTemplate stringRedisTemplate;

    /**
     * 採用RedisTemplate 將字符串信息寫入緩存中並讀取出來
     */
    @Test
    public void tetRedis() {

        log.info("=======開始RedisTemplate 操作組件實戰");

        //定義字符串內容及存入緩存的Key
        final String content = "RedisTemplate實戰字符串信息";
        final String key = "redis:template:one:string";

        ValueOperations valueOperations = redisTemplate.opsForValue(); //Redis 通用操作組件

        log.info("寫入緩衝中的內容：{}", content);
        valueOperations.set(key, content);  //將信息寫入緩衝中

        Object result = valueOperations.get(key); //從緩衝中讀取內容
        log.info("讀取出來的內容：{}", result);

    }

    /**
     * 採用RedisTemplate 將對象信息序列化爲JSON 格式字符串後寫入緩衝中
     * 然後將其讀取出來, 最後反序列化解析其中的內容並展示在控制檯上
     */
    @Test
    public void testRedisJSON() {
        log.info("==開始RedisTemplate組件實戰操作==");

        User user = new User(1, "debug", "阿修羅");
        ValueOperations valueOperations = redisTemplate.opsForValue(); //Redis 通用操作組件
        final String key = "redis:template:one:object";

        /**
         *   將序列化後的信息寫入緩衝中
         */
        try {
            final String content = objectMapper.writeValueAsString(user);
            valueOperations.set(key, content);
            log.info("寫入緩衝對象的信息：{}", user);
        } catch (Exception e) {
            log.error("json 序列化失敗:{}", user);
        }

        /**
         * 從緩衝中讀取內容
         */
        Optional.ofNullable(valueOperations.get(key)).ifPresent(x -> {
            try {
                User userReceive = objectMapper.readValue(x.toString(), User.class);
                log.info("讀取內容並反序列化後的結果:{}", userReceive);

            } catch (Exception e) {
                log.error("讀取信息異常,{}", x);
            }

        });
    }

    /**
     * 下面是採用StringRedisTemplate 實現上面兩個需求
     */

    @Test
    public void testRedisString() {

        log.info("======開始StringRedisTemplate 操作組件實戰======");

        final String content = "StringRedisTemplate 實戰字符串信息";
        final String key = "redis:String ==>";

        log.info("寫入緩衝的內容:{}", content);
        ValueOperations valueOperations = stringRedisTemplate.opsForValue();
        valueOperations.set(key, content);

        Object result = valueOperations.get(key);
        log.info("讀取出來的內容：{}", result);
    }

    @Test
    public void testRedisStringObject() {
        log.info(" ===開始StringRedisTemplate操作組件實戰===");
        User user = new User(2, "JSON==Oject", "阿凡達");
        ValueOperations valueOperations = stringRedisTemplate.opsForValue();

        final String key = "redis:string:object ==>";
        try {
            final String content = objectMapper.writeValueAsString(user);
            valueOperations.set(key, content);
            log.info("寫入緩衝對象的信息：{}", content);
        } catch (Exception e) {
            log.error("JSON 序列化失敗：{}", user);
        }

        Optional.ofNullable(valueOperations.get(key)).ifPresent(x -> {
            try {
                User userReceive = objectMapper.readValue(x.toString(), User.class);
                log.info("讀取信息並返回序列化的結果：{}", userReceive);
            } catch (Exception e) {
                log.error("讀取信息異常: {}", x);
            }
        });
    }


}