当已经利用Spark往Redis写入数据,这部分需自行查看资料,比较简单:
// 调用 sparkContext 实例化进行计算
val sc: SparkContext = {
val sparkConf = new SparkConf()
.setAppName(this.getClass.getSimpleName.stripSuffix("$"))
.setMaster("local[3]")
.set("spark.redis.host", "192.168.88.1xx") //redis 主机节点
.set("spark.redis.port", "6379") //端口号,不填默认为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)) // 函数操作
// 写入redis
sc.toRedisKV(RddData)
写入数据后,key 和 value 均为字符串类型
这时,如果通过 Spring Boot jquery 之 ajax 直接读取 redis 里面的数据
Object o = redisTemplate.opsForValue().get("1");
System.out.println(o);
报异常:
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
可以看到数据出现了,但是没有读出来,初步估计是 RedisTemplate 出现了问题。
在SpringBoot 中注解 @Configuration 的模板部分出现了问题
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;
}
}
仅仅需要将 // value序列化方式采用jackson, 改成 stringRedisSerializer 类型就能读出来了。
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;
}
}
关于SpringBoot 如何直接读取Redis 里面的数据就不介绍了,网上有很多教程哪。
左侧有个推荐,有用就推荐下吧?☺