想体验一下java的虚拟线程，新建一个springboot项目，使用版本是3.2。其他功能测试还好，当测试到redis功能时，发现连接不上服务器了。经过检查是因为redis配置文件读取配置前缀发生了变化，2.x版本的配置前缀是 spring.redis 到 3.x变为了 spring.data.redis，所以配置文件也要做相应的改变，否则读取配置文件读取不到。
2.x的配置文件：
spring:
redis:
host: 192.168.56.101
port: 6379
password: 123456
database: 1
timeout: 3000
lettuce:
pool:
max-active: 16
max-idle: 8
max-wait: -1
min-idle: 1
3.x的配置文件：
spring:
data:
redis:
host: 192.168.56.101
port: 6379
password: 123456
database: 1
timeout: 3000
lettuce:
pool:
max-active: 16
max-idle: 8
max-wait: -1
min-idle: 1
如果你刚好测试服务和redis在一个机器上，可能不会出现问题，因为读取不到配置内容默认也会连接到本地的redis服务器。redis配置信息会加载到配置类 org.springframework.boot.autoconfigure.data.redis.RedisProperties 中。
下面是报错内容：
org.springframework.data.redis.RedisConnectionFailureException: Unable to connect to Redis
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.translateException(LettuceConnectionFactory.java:1805)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1736)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getNativeConnection(LettuceConnectionFactory.java:1538)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.lambda$getConnection$0(LettuceConnectionFactory.java:1518)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.doInLock(LettuceConnectionFactory.java:1478)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$SharedConnection.getConnection(LettuceConnectionFactory.java:1515)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getSharedConnection(LettuceConnectionFactory.java:1199)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory.getConnection(LettuceConnectionFactory.java:1006)
at org.springframework.data.redis.core.RedisConnectionUtils.fetchConnection(RedisConnectionUtils.java:194)
at org.springframework.data.redis.core.RedisConnectionUtils.doGetConnection(RedisConnectionUtils.java:143)
at org.springframework.data.redis.core.RedisConnectionUtils.getConnection(RedisConnectionUtils.java:104)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:393)
at org.springframework.data.redis.core.RedisTemplate.execute(RedisTemplate.java:373)
at org.springframework.data.redis.core.AbstractOperations.execute(AbstractOperations.java:97)
at org.springframework.data.redis.core.DefaultValueOperations.get(DefaultValueOperations.java:50)
at com.clou.ess.controller.DemoController.demo3(DemoController.java:48)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at org.springframework.util.ReflectionUtils.invokeMethod(ReflectionUtils.java:281)
at org.springframework.cloud.context.scope.GenericScope$LockedScopedProxyFactoryBean.invoke(GenericScope.java:482)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:184)
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.proceed(CglibAopProxy.java:765)
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:717)
at com.clou.ess.controller.DemoController$$SpringCGLIB$$0.demo3(<generated>)
at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
at java.base/java.lang.reflect.Method.invoke(Method.java:580)
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:254)
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:182)
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:118)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:917)
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:829)
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87)
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:1089)
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:979)
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:1014)
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:903)
at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:564)
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:885)
at jakarta.servlet.http.HttpServlet.service(HttpServlet.java:658)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:205)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:51)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:100)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
at org.springframework.web.filter.FormContentFilter.doFilterInternal(FormContentFilter.java:93)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
at org.springframework.web.filter.ServerHttpObservationFilter.doFilterInternal(ServerHttpObservationFilter.java:109)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:201)
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:116)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:174)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:149)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:167)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:90)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:482)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:115)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:93)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:74)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:340)
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:391)
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:63)
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:896)
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1744)
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:52)
at org.apache.tomcat.util.threads.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1191)
at org.apache.tomcat.util.threads.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:659)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.base/java.lang.Thread.run(Thread.java:1583)
Caused by: org.springframework.data.redis.connection.PoolException: Could not get a resource from the pool
at org.springframework.data.redis.connection.lettuce.LettucePoolingConnectionProvider.getConnection(LettucePoolingConnectionProvider.java:104)
at org.springframework.data.redis.connection.lettuce.LettuceConnectionFactory$ExceptionTranslatingConnectionProvider.getConnection(LettuceConnectionFactory.java:1734)
... 74 common frames omitted
Caused by: io.lettuce.core.RedisConnectionException: Unable to connect to localhost/<unresolved>:6379
at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:78)
at io.lettuce.core.RedisConnectionException.create(RedisConnectionException.java:56)
at io.lettuce.core.AbstractRedisClient.getConnection(AbstractRedisClient.java:350)
at io.lettuce.core.RedisClient.connect(RedisClient.java:215)
at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.lambda$getConnection$1(StandaloneConnectionProvider.java:112)
at java.base/java.util.Optional.orElseGet(Optional.java:364)
at org.springframework.data.redis.connection.lettuce.StandaloneConnectionProvider.getConnection(StandaloneConnectionProvider.java:112)
at org.springframework.data.redis.connection.lettuce.LettucePoolingConnectionProvider.lambda$getConnection$0(LettucePoolingConnectionProvider.java:93)
at io.lettuce.core.support.ConnectionPoolSupport$RedisPooledObjectFactory.create(ConnectionPoolSupport.java:211)
at io.lettuce.core.support.ConnectionPoolSupport$RedisPooledObjectFactory.create(ConnectionPoolSupport.java:201)
at org.apache.commons.pool2.BasePooledObjectFactory.makeObject(BasePooledObjectFactory.java:71)
at org.apache.commons.pool2.impl.GenericObjectPool.create(GenericObjectPool.java:566)
at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:306)
at org.apache.commons.pool2.impl.GenericObjectPool.borrowObject(GenericObjectPool.java:233)
at io.lettuce.core.support.ConnectionPoolSupport$1.borrowObject(ConnectionPoolSupport.java:122)
at io.lettuce.core.support.ConnectionPoolSupport$1.borrowObject(ConnectionPoolSupport.java:117)
at org.springframework.data.redis.connection.lettuce.LettucePoolingConnectionProvider.getConnection(LettucePoolingConnectionProvider.java:99)
... 75 common frames omitted
Caused by: io.netty.channel.AbstractChannel$AnnotatedConnectException: Connection refused: no further information: localhost/127.0.0.1:6379
Caused by: java.net.ConnectException: Connection refused: no further information
at java.base/sun.nio.ch.Net.pollConnect(Native Method)
at java.base/sun.nio.ch.Net.pollConnectNow(Net.java:682)
at java.base/sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:973)
at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:337)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:334)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:776)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:724)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:650)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:562)
at io.netty.util.concurrent.SingleThreadEventExecutor$4.run(SingleThreadEventExecutor.java:997)
at io.netty.util.internal.ThreadExecutorMap$2.run(ThreadExecutorMap.java:74)
at io.netty.util.concurrent.FastThreadLocalRunnable.run(FastThreadLocalRunnable.java:30)
at java.base/java.lang.Thread.run(Thread.java:1583)