<!-- Spring Boot Starter -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter</artifactId>
</dependency>

<!-- Web 支持 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

<!-- Redis 支持 -->
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>

<!-- Lettuce 客戶(hù)端 -->
<dependency>
    <groupId>io.lettuce.core</groupId>
    <artifactId>lettuce-core</artifactId>
    <version>6.2.4</version>
</dependency>

-- get_or_set_default.lua
local key = KEYS[1]
local defaultVal = ARGV[1]

local value = redis.call('GET', key)
if not value then
    redis.call('SET', key, defaultVal)
    value = defaultVal
end
return value

import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.core.script.DefaultRedisScript;
import org.springframework.stereotype.Service;

import javax.annotation.PostConstruct;
import java.io.IOException;
import java.nio.file.Files;
import java.nio.file.Path;
import java.nio.file.Paths;
import java.util.Collections;

@Service
public class LuaScriptLoader {

    private final RedisTemplate<String, Object> redisTemplate;

    // 存儲(chǔ)腳本的 SHA1 值
    public static String GET_OR_SET_DEFAULT_SHA;

    public LuaScriptLoader(RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    @PostConstruct
    public void loadScripts() throws IOException {
        Path scriptPath = Paths.get("src/main/resources/lua/get_or_set_default.lua");
        String scriptContent = Files.readString(scriptPath);

        DefaultRedisScript<String> redisScript = new DefaultRedisScript<>();
        redisScript.setScriptText(scriptContent);
        redisScript.setResultType(String.class);

        // 執(zhí)行 SCRIPT LOAD 命令加載腳本
        GET_OR_SET_DEFAULT_SHA = redisTemplate.execute(
                redisScript,
                Collections.singletonList("dummyKey"),
                "defaultValue"
        );

        System.out.println("Lua Script SHA1: " + GET_OR_SET_DEFAULT_SHA);
    }
}

import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Service;

import java.util.Collections;

@Service
public class RedisLuaService {

    private final RedisTemplate<String, Object> redisTemplate;

    public RedisLuaService(RedisTemplate<String, Object> redisTemplate) {
        this.redisTemplate = redisTemplate;
    }

    /**
     * 調(diào)用 Lua 腳本：根據(jù) key 獲取值，若不存在則設(shè)置默認(rèn)值并返回
     */
    public String getOrSetDefault(String key, String defaultValue) {
        return (String) redisTemplate.execute(
                LuaScriptLoader.GET_OR_SET_DEFAULT_SHA,
                Collections.singletonList(key),
                defaultValue
        );
    }
}

import org.springframework.web.bind.annotation.*;

@RestController
@RequestMapping("/redis")
public class RedisLuaController {

    private final RedisLuaService redisLuaService;

    public RedisLuaController(RedisLuaService redisLuaService) {
        this.redisLuaService = redisLuaService;
    }

    @GetMapping("/get-or-set")
    public String getOrDefault(
            @RequestParam String key,
            @RequestParam(required = false, defaultValue = "default_value") String defaultValue) {
        return redisLuaService.getOrSetDefault(key, defaultValue);
    }
}

redis-server

mvn spring-boot:run