Error: io.lettuce.core.RedisConnectionException Unable to connect to localhost/<unresolved> - spring-boot

Question

I'm trying this tutorial from a book where there's an api running and when the application with the redis code gets called, it's suppose to output the information from the api. However, this is the error I get when I run the application:
org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis; nested exception is io.lettuce.core.RedisConnectionException: Unable to connect to localhost/<unresolved>:6379
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.translateException(LettuceConnectionFactory.java:1689) ~[spring-data-redis-2.6.3.jar:2.6.3]
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1597) ~[spring-data-redis-2.6.3.jar:2.6.3]
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1383) ~[spring-data-redis-2.6.3.jar:2.6.3]
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getConnection(LettuceConnectionFactory.java:1366) ~[spring-data-redis-2.6.3.jar:2.6.3]
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getSharedConnection(LettuceConnectionFactory.java:1093) ~[spring-data-redis-2.6.3.jar:2.6.3]
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getConnection(LettuceConnectionFactory.java:421) ~[spring-data-redis-2.6.3.jar:2.6.3]
at com.demo.springdataexample.demo.PlaneFinderPoller.pollPlanes(PlaneFinderPoller.java:25) ~[classes/:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:na]
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:77) ~[na:na]
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:na]
at java.base/java.lang.reflect.Method.invoke(Method.java:568) ~[na:na]
at org.springframework.scheduling.support.ScheduledMethodRunnable.run(ScheduledMethodRunnable.java:84) ~[spring-context-5.3.18.jar:5.3.18]
at org.springframework.scheduling.support.DelegatingErrorHandlingRunnable.run(DelegatingErrorHandlingRunnable.java:54) ~[spring-context-5.3.18.jar:5.3.18]
at java.base/java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:539) ~[na:na]
at java.base/java.util.concurrent.FutureTask.runAndReset(FutureTask.java:305) ~[na:na]
at java.base/java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:305) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136) ~[na:na]
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635) ~[na:na]
at java.base/java.lang.Thread.run(Thread.java:833) ~[na:na]
Caused by: io.lettuce.core.RedisConnectionException: Unable to connect to localhost/<unresolved>:6379
at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:78) ~[lettuce-core-6.1.8.RELEASE.jar:6.1.8.RELEASE]
at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:56) ~[lettuce-core-6.1.8.RELEASE.jar:6.1.8.RELEASE]
at io.lettuce.core.AbstractRedisClient.getConnection(AbstractRedisClient.java:330) ~[lettuce-core-6.1.8.RELEASE.jar:6.1.8.RELEASE]
at io.lettuce.core.RedisClient.connect(RedisClient.java:216) ~[lettuce-core-6.1.8.RELEASE.jar:6.1.8.RELEASE]
at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.lambda$getConnection$1(StandaloneConnectionProvider.java:115) ~[spring-data-redis-2.6.3.jar:2.6.3]
at java.base/java.util.Optional.orElseGet(Optional.java:364) ~[na:na]
at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.getConnection(StandaloneConnectionProvider.java:115) ~[spring-data-redis-2.6.3.jar:2.6.3]
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1595) ~[spring-data-redis-2.6.3.jar:2.6.3]
... 17 common frames omitted
Below is the code:
Main class:
package com.demo.springdataexample.demo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.context.annotation.Bean;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer;
import org.springframework.data.redis.serializer.StringRedisSerializer;
#SpringBootApplication
public class SburRedisApplication {
#Bean
public RedisOperations<String, Aircraft>
redisOperations(RedisConnectionFactory factory) {
Jackson2JsonRedisSerializer<Aircraft> serializer =
new Jackson2JsonRedisSerializer<>(Aircraft.class);
RedisTemplate<String, Aircraft> template = new RedisTemplate<>();
template.setConnectionFactory(factory);
template.setDefaultSerializer(serializer);
template.setKeySerializer(new StringRedisSerializer());
return template;
}
public static void main(String[] args) {
SpringApplication.run(SburRedisApplication.class, args);
}
}
PlaneFinderPoller.java
package com.demo.springdataexample.demo;
import org.springframework.data.redis.connection.RedisConnectionFactory;
import org.springframework.data.redis.core.RedisOperations;
import org.springframework.scheduling.annotation.EnableScheduling;
import org.springframework.scheduling.annotation.Scheduled;
import org.springframework.stereotype.Component;
import org.springframework.web.reactive.function.client.WebClient;
#EnableScheduling
#Component
public class PlaneFinderPoller {
private WebClient webclient =
WebClient.create("http://localhost:7634/aircraft");
private final RedisConnectionFactory connectionFactory;
private final RedisOperations<String, Aircraft> redisOperations;
public PlaneFinderPoller(RedisConnectionFactory connectionFactory,
RedisOperations<String, Aircraft> redisOperations)
{
this.connectionFactory = connectionFactory;
this.redisOperations = redisOperations;
}
#Scheduled(fixedRate = 1000)
private void pollPlanes(){
connectionFactory.getConnection().serverCommands().flushDb();
webclient.get()
.retrieve()
.bodyToFlux(Aircraft.class)
.filter(plane -> !plane.getReg().isEmpty())
.toStream()
.forEach(ac -> redisOperations.opsForValue().set(ac.getReg(), ac));
redisOperations.opsForValue()
.getOperations()
.keys("*")
.forEach(ac -> System.out.println(redisOperations.opsForValue().get(ac)));
}
}
Aircraft.java

Answer 1

I find that book author in this issue says running redis:
https://github.com/mkheck/SpringBootUpAndRunning/issues/1