Caused by: java.lang.NoClassDefFoundError: org/apache/commons/pool2/impl/GenericObjectPoolConfig
	at org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration$LettucePoolingClientConfigurationBuilder.<init>(LettucePoolingClientConfiguration.java:94) ~[spring-data-redis-2.2.3.RELEASE.jar:2.2.3.RELEASE]
	at org.springframework.data.redis.connection.lettuce.LettucePoolingClientConfiguration.builder(LettucePoolingClientConfiguration.java:51) ~[spring-data-redis-2.2.3.RELEASE.jar:2.2.3.RELEASE]
	at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration$PoolBuilderFactory.createBuilder(LettuceConnectionConfiguration.java:136) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.createBuilder(LettuceConnectionConfiguration.java:100) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.getLettuceClientConfiguration(LettuceConnectionConfiguration.java:86) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration.redisConnectionFactory(LettuceConnectionConfiguration.java:68) ~[spring-boot-autoconfigure-2.2.2.RELEASE.jar:2.2.2.RELEASE]
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_131]
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_131]
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_131]
	at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_131]
	at org.springframework.beans.factory.support.SimpleInstantiationStrategy.instantiate(SimpleInstantiationStrategy.java:154) ~[spring-beans-5.2.2.RELEASE.jar:5.2.2.RELEASE]

pom.xml

<dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
            <version>2.2.2.RELEASE</version>
</dependency>

缺少jar依赖，添加以下内容

<!-- https://mvnrepository.com/artifact/org.apache.commons/commons-pool2 -->
<dependency>
    <groupId>org.apache.commons</groupId>
    <artifactId>commons-pool2</artifactId>
    <version>2.6.0</version>
</dependency>