SpringBoot 取出redis里面的數據，報錯: org.springframework.data.redis.serializer.SerializationException: Could not read JSON: Unexpected character (',' (code 44)): Expected space separating root-level values

當已經利用Spark往Redis寫入數據，這部分需自行查看資料，比較簡單：

// 調用 sparkContext 實例化進行計算
val sc: SparkContext = {
  val sparkConf = new SparkConf()
    .setAppName(this.getClass.getSimpleName.stripSuffix("$"))
    .setMaster("local[3]")

    .set("spark.redis.host", "192.168.88.1xx") //redis 主機節點
    .set("spark.redis.port", "6379") //端口號，不填默認為6379
    .set("spark.redis.auth", "123456")

  new SparkContext(sparkConf)
}
sc.setLogLevel("WARN")
// 求data
val stEndRdd: RDD[(Int, Int)] = sc.makeRDD(stEndArr)

val allPathSeq: RDD[(String, String)] = stEndRdd.map(getGraphCalcu(_)(g))  // 函數操作


// 寫入redis 
sc.toRedisKV(RddData)

寫入數據后，key 和 value 均為字符串類型

 

 這時，如果通過 Spring Boot jquery 之 ajax 直接讀取 redis 里面的數據

Object o = redisTemplate.opsForValue().get("1");
System.out.println(o);　　

報異常：

org.springframework.data.redis.serializer.SerializationException: Could not read JSON: 
Unexpected character (',' (code 44)): Expected space separating root-level values
 at [Source: (byte[])"33,1232,1231,1230,1229,1228,1227,324,1438,1439,1440"; line: 1, column: 4]; nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character (',' (code 44)): Expected space separating root-level values 　　

可以看到數據出現了，但是沒有讀出來，初步估計是 RedisTemplate 出現了問題。

在SpringBoot 中注解 @Configuration 的模板部分出現了問題

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
public class RedisConfig {

    @Bean
    @SuppressWarnings("all")
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();
        template.setConnectionFactory(factory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);

        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        // key采用String的序列化方式
        template.setKeySerializer(stringRedisSerializer);
        // hash的key也采用String的序列化方式
        template.setHashKeySerializer(stringRedisSerializer);

        // value序列化方式采用jackson,
        template.setValueSerializer(jackson2JsonRedisSerializer);
        // hash的value序列化方式采用jackson
        template.setHashValueSerializer(jackson2JsonRedisSerializer);

        template.afterPropertiesSet();
        return template;
    }
}

僅僅需要將  // value序列化方式采用jackson,  改成 stringRedisSerializer 類型就能讀出來了。

import com.fasterxml.jackson.annotation.JsonAutoDetect;
import com.fasterxml.jackson.annotation.PropertyAccessor;
import com.fasterxml.jackson.databind.ObjectMapper;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;

@Configuration
public class RedisConfig {

    @Bean
    @SuppressWarnings("all")
    public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {
        RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();
        template.setConnectionFactory(factory);
        Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
        ObjectMapper om = new ObjectMapper();
        om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        jackson2JsonRedisSerializer.setObjectMapper(om);

        StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
        // key采用String的序列化方式
        template.setKeySerializer(stringRedisSerializer);
        // hash的key也采用String的序列化方式
        template.setHashKeySerializer(stringRedisSerializer);

        // value序列化方式采用 String
        template.setValueSerializer(stringRedisSerializer);
        // hash的value序列化方式采用String
        template.setHashValueSerializer(stringRedisSerializer);


        template.afterPropertiesSet();
        return template;
    }
}

關於SpringBoot 如何直接讀取Redis 里面的數據就不介紹了，網上有很多教程哪。

左側有個推薦，有用就推薦下吧？☺