redisTemplate不支持zpopmax，解决方案使用reverseRangeWithScore

在redis客户端可以使用zpopmax

redisTemplate不支持zpopmax

解决方案

使用reverseRangeWithScore
接下来我们进行测试

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 {@Autowiredprivate RedisTemplate redisTemplate;@Testpublic 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}
}

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


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}

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*/@Beanpublic RedisTemplate redisTemplate(LettuceConnectionFactory lettuceConnectionFactory) {RedisTemplate redisTemplate = new RedisTemplate();redisTemplate.setConnectionFactory(lettuceConnectionFactory);//设置key序列化方式stringredisTemplate.setKeySerializer(new StringRedisSerializer());//设置value的序列化方式jsonredisTemplate.setValueSerializer(new GenericJackson2JsonRedisSerializer());redisTemplate.setHashKeySerializer(new StringRedisSerializer());redisTemplate.setHashValueSerializer(new GenericJackson2JsonRedisSerializer());redisTemplate.afterPropertiesSet();return redisTemplate;}
}