redisTemplate不支持zpopmax，解决方案使用reverseRangeWithScore

红太狼 2024-02-19 10:04 5阅读 0赞

在redis客户端可以使用zpopmax  
![在这里插入图片描述][b5f37263074d47b19c26638613fbbb54.png]  
redisTemplate不支持zpopmax  
![在这里插入图片描述][6c359b534bec4ddfa1282d4ba960ea26.png]

### 解决方案 ###

使用reverseRangeWithScore  
接下来我们进行测试  
![在这里插入图片描述][e64233452db344b6970cebb05491f862.png]

我们要返回最大的value，应该是c

import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.data.redis.core.ZSetOperations;
    import org.springframework.test.context.junit4.SpringRunner;
    
    import java.util.Set;
    
    @SpringBootTest
    @RunWith(SpringRunner.class)
    public class TEST1 {
        
    
        @Autowired
        private RedisTemplate redisTemplate;
    
        @Test
        public void Data(){
        
    //        redisTemplate.opsForZSet().add("goods","a",10);
    //        redisTemplate.opsForZSet().add("goods","b",10);
    //        redisTemplate.opsForZSet().add("goods","c",11);
            String goods = zPopMaxFromSet("goods");
            System.out.println(goods);
    
        }
    
    
        public String zPopMaxFromSet(String setName) {
        
            ZSetOperations<String, String> zSetOperations = redisTemplate.opsForZSet();
            Set<ZSetOperations.TypedTuple<String>> maxElements = zSetOperations.reverseRangeWithScores(setName, 0, 0);
    
            if (!maxElements.isEmpty()) {
        
                ZSetOperations.TypedTuple<String> maxElement = maxElements.iterator().next();
                //获取值
                String element = maxElement.getValue();
                //获取得分
                Double score = maxElement.getScore();
                zSetOperations.remove(setName, element);
                return element;
            }
            return null; // 集合为空
        }
    }

![在这里插入图片描述][a2d01ed146064657ac83042afa309661.png]  
**`有人想问了zSetOperations.reverseRangeWithScores(setName, 0, 0); 0,0代表什么`**  
开始索引位置和结束位置  
![在这里插入图片描述][57453a264dab477892ea531c1bcb4be3.png]  
![在这里插入图片描述][e68c9c704cb34a2fb48a4d19437bdf55.png]  
测试

@ApiOperation("测试")
        @GetMapping("/test/{start}/{end}")
        public List<String> testRedis(@PathVariable Integer start, @PathVariable Integer end){
        
            ZSetOperations<String, String> zSetOperations = redisTemplate.opsForZSet();
            Set<ZSetOperations.TypedTuple<String>> maxElements = zSetOperations.reverseRangeWithScores("goods", start,end );
            Iterator<ZSetOperations.TypedTuple<String>> iterator = maxElements.iterator();
            ArrayList<String> list = new ArrayList<>();
            while(iterator.hasNext()){
        
                list.add(iterator.next().getValue());
    
            }
            return list; // 集合为空
        }

![在这里插入图片描述][044ad98850d746f38f83033d62069e1d.png]  
![在这里插入图片描述][f8f2776718e74b7fb03d7c6aee3cf4f1.png]  
![在这里插入图片描述][dfcd681a902b43708e009ed6a06308e4.png]

### 记得序列化 ###

import org.springframework.context.annotation.Bean;
    import org.springframework.context.annotation.Configuration;
    import org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory;
    import org.springframework.data.redis.core.RedisTemplate;
    import org.springframework.data.redis.serializer.GenericJackson2JsonRedisSerializer;
    import org.springframework.data.redis.serializer.StringRedisSerializer;
    
    import java.io.Serializable;
    
    
    
    @Configuration
    public class RedisConfig {
        
        /**
         * @param lettuceConnectionFactory
         * @return
         *
         * redis序列化的工具配置类，下面这个请一定开启配置
         * 127.0.0.1:6379> keys *
         * 1) "ord:102"  序列化过
         * 2) "\xac\xed\x00\x05t\x00\aord:102"   野生，没有序列化过
         */
        @Bean
        public RedisTemplate redisTemplate(LettuceConnectionFactory lettuceConnectionFactory) {
        
            RedisTemplate redisTemplate = new RedisTemplate();
    
            redisTemplate.setConnectionFactory(lettuceConnectionFactory);
            //设置key序列化方式string
            redisTemplate.setKeySerializer(new StringRedisSerializer());
            //设置value的序列化方式json
            redisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());
    
            redisTemplate.setHashKeySerializer(new StringRedisSerializer());
            redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());
    
            redisTemplate.afterPropertiesSet();
    
            return redisTemplate;
        }
    }

[b5f37263074d47b19c26638613fbbb54.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/fe47a665ad124bf5a564f8cf0eb90bb6.png
[6c359b534bec4ddfa1282d4ba960ea26.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/b9b6a4a4befa43928235af4c38c5d10b.png
[e64233452db344b6970cebb05491f862.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/47f89702991544e7ba77da59e586dda7.png
[a2d01ed146064657ac83042afa309661.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/6bed71d7db7848709633885cb9f195a8.png
[57453a264dab477892ea531c1bcb4be3.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/88fe0ca6cae148cc8d4de45dffd5460f.png
[e68c9c704cb34a2fb48a4d19437bdf55.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/0e490542cb834b818f0ee5ed8df37237.png
[044ad98850d746f38f83033d62069e1d.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/30ff281e0fd1492d935b3396de87e25e.png
[f8f2776718e74b7fb03d7c6aee3cf4f1.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/19a83c8e404446d2a62439221d9d70bb.png
[dfcd681a902b43708e009ed6a06308e4.png]: https://image.dandelioncloud.cn/pgy_files/images/2024/02/19/88f6e963c79d4234b4de94fdb4c8e652.png