java - lua - redis 完成商品库存的删减

java调用lua脚本完成对商品库存的管理

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//lua脚本 获取到内存不够的商品StringBuilder sb = new StringBuilder();//定义一个数组存储可能缺少库存的值sb.append(" local  table = {} ");//获取值sb.append("  local values = redis.call('mget',unpack(KEYS)) ");//如果不够就放到table之中sb.append("  for i = 1, #KEYS do ");sb.append("     if tonumber(ARGV[i]) > tonumber(values[i]) then ");sb.append("         table[#table + 1] = KEYS[i] .. '=' .. values[i] ");sb.append("     end ");sb.append("  end");//判断 库存是否sb.append("  if #table > 0 then ");sb.append("  return table ");sb.append("  end ");sb.append("  for i = 1, #KEYS do  ");sb.append("  redis.call('decrby',KEYS[i],ARGV[i]) ");sb.append("  end ");sb.append("  return {} ");

lua 脚本的内容作业个简单的判断，相信逻辑大家都明白，只是lua脚本语言本身不太熟练，这里有一个简单模板，亲测可用不一定时最优的模板

测试

这里的redisTemplate在官方jarbao中采用的jdk序列化方式导致中文乱码，我这里注入的是自己重写的（网上抄的），因为非本文重要内容，不再详述

   @AutowiredRedisTemplate<Object, Object> redisTemplate;@Resource(name = "redisTemplate")ValueOperations valueOperations;@ResourceStringRedisTemplate stringRedisTemplate;@Test//通过lua脚本多线程操作库存void get() throws IOException {String key1  = "apple";String key2  = "banana";String key3  = "栗子";//三个商品并设置其库存量valueOperations.set(key1,15L);valueOperations.set(key2,8L);valueOperations.set(key3,6L);//lua脚本 获取到内存不够的商品StringBuilder sb = new StringBuilder();//定义一个数组存储可能缺少库存的值sb.append(" local  table = {} ");//获取值sb.append("  local values = redis.call('mget',unpack(KEYS)) ");//如果不够就放到table之中sb.append("  for i = 1, #KEYS do ");sb.append("     if tonumber(ARGV[i]) > tonumber(values[i]) then ");sb.append("         table[#table + 1] = KEYS[i] .. '=' .. values[i] ");sb.append("     end ");sb.append("  end");//判断 库存是否sb.append("  if #table > 0 then ");sb.append("  return table ");sb.append("  end ");sb.append("  for i = 1, #KEYS do  ");sb.append("  redis.call('decrby',KEYS[i],ARGV[i]) ");sb.append("  end ");sb.append("  return {} ");RedisScript<List> script = RedisScript.of(sb.toString(),List.class);ExecutorService executorService = Executors.newCachedThreadPool();for (int i = 0; i < 10; i++) {int i1 = RandomUtil.randomInt(1, 5);executorService.execute(()->{List execute = stringRedisTemplate.execute(script,CollUtil.newArrayList(key1, key2, key3), String.valueOf(i1), String.valueOf(i1), String.valueOf(i1));if(execute.isEmpty()){System.out.println("库存足够，存储成功");return;}for (Object obj : execute){String[] split = obj.toString().split("=");System.out.println(StrUtil.format("商品{} 需求量:{} 库存不足，仅剩{}",split[0],i1,split[1]));}});}//测试中执行所以需要阻塞使用防止因为多线程执行的时候因为其他线程走完导致的测试结束System.in.read();}