public interface CacheService {

    /**
     * 添加一個字符串鍵值對
     * @param key 鍵
     * @param value 值
     */
    void setString(String key, String value);
}

import com.hezy.service.CacheService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

@Service
public class RedisServiceImpl implements CacheService {

    @Autowired
    private RedisTemplate<String, String> redisTemplate;


    @Override
    public void setString(String key, String value) {
        redisTemplate.opsForValue().set(key, value);
    }
}

import com.hezy.service.impl.RedisServiceImpl;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

@SpringBootTest
public class RedisServiceImplTest {

    @Autowired
    private RedisServiceImpl redisService;

    @Test
    public void test1() {
        String key = "content";
        String value = "這是一段分非常大非常大的字符串…………………………非常大";
        redisService.setString(key, value);
    }
}

    /**
     * 分段存儲
     * @param key 鍵
     * @param value 值
     * @param chunkSize 每個分段大小
     */
    void setStrSub(String key, String value, int chunkSize);

    @Override
    public void setStrSub(String key, String value, int chunkSize) {
        // 將value，按照length，分成多個部分
        int totalChunks = (int) Math.ceil((double) value.length() / chunkSize);
        // 定義一個分段數(shù)據(jù)key集合
        List<String> subKeys = new ArrayList<>(totalChunks);
        // 將字符串分成多段
        for (int i = 0; i < totalChunks; i++) {
            // 計(jì)算分段起止位置
            int startIndex = i * chunkSize;
            int endIndex = Math.min(startIndex + chunkSize, value.length());
            // 獲取對應(yīng)分段數(shù)據(jù)
            String chunkValue = value.substring(startIndex, endIndex);
            // 拼接分段key
            String subKey = key + "_" + i;
            // 存儲分段數(shù)據(jù)
            setString(subKey, chunkValue);
            // 將分段key添加到集合
            subKeys.add(subKey);
        }
        // 分段key添加到集合
        setList(key, subKeys);
    }

    @Override
    public void setList(String key, List value) {
        redisTemplate.opsForList().rightPushAll(key, value);
    }

    @Test
    public void test2() {
        String key = "content";
        String value = "這是一段分非常大非常大的字符串…………………………非常大";
        redisService.setStrSub(key, value, 5);
    }

    /**
     * 獲取字符串（分段）
     * @param key
     * @return
     */
    String getStrSub(String key);

    @Override
    public String getStrSub(String key) {
        // 先把分段key獲取出來
        List<String> list = getList(key);
        // 字符串拼接，用StringBuilder，線程安全
        StringBuilder stringBuilder = new StringBuilder();
        for (String subKey : list) {
            String subValue = getString(subKey);
            // 這里要跳過null，不然最后輸出會把null轉(zhuǎn)為字符串
            if (subValue == null) {
                continue;
            }
            stringBuilder.append(subValue);
        }
        // 如果沒有數(shù)據(jù)，返回null
        return "".contentEquals(stringBuilder) ? null : stringBuilder.toString();
    }

    @Override
    public List getList(String key) {
        return redisTemplate.opsForList().range(key, 0, -1);
    }

    @Test
    public void test3() {
        String content = redisService.getStrSub("content");
        System.out.println(content);
    }