遇到的报错问题：

com.alibaba.dubbo.remoting.RemotingException: message can not send, because channel is closed . url:dubbo://192.168.43.177:20880/com.test.server.MyService?anyhost=true&application=dubbo-consumer&check=false&codec=dubbo&dubbo=2.6.0&generic=false&heartbeat=60000&interface=com.test.server.MyService&methods=queryAllStudent,saveStudent,toQueryKC&pid=23252&register.ip=192.168.43.177&remote.timestamp=1543217795411&side=consumer&timestamp=1543217831217
    at com.alibaba.dubbo.remoting.transport.AbstractClient.send(AbstractClient.java:254) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.remoting.transport.AbstractPeer.send(AbstractPeer.java:52) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.remoting.exchange.support.header.HeaderExchangeChannel.request(HeaderExchangeChannel.java:111) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.remoting.exchange.support.header.HeaderExchangeClient.request(HeaderExchangeClient.java:86) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.dubbo.ReferenceCountExchangeClient.request(ReferenceCountExchangeClient.java:77) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.dubbo.DubboInvoker.doInvoke(DubboInvoker.java:95) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.AbstractInvoker.invoke(AbstractInvoker.java:142) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.listener.ListenerInvokerWrapper.invoke(ListenerInvokerWrapper.java:73) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.monitor.support.MonitorFilter.invoke(MonitorFilter.java:74) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:68) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.dubbo.filter.FutureFilter.invoke(FutureFilter.java:53) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:68) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.filter.ConsumerContextFilter.invoke(ConsumerContextFilter.java:47) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.ProtocolFilterWrapper$1.invoke(ProtocolFilterWrapper.java:68) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.protocol.InvokerWrapper.invoke(InvokerWrapper.java:52) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.cluster.support.FailoverClusterInvoker.doInvoke(FailoverClusterInvoker.java:77) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.cluster.support.AbstractClusterInvoker.invoke(AbstractClusterInvoker.java:232) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.cluster.support.wrapper.MockClusterInvoker.invoke(MockClusterInvoker.java:70) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.rpc.proxy.InvokerInvocationHandler.invoke(InvokerInvocationHandler.java:51) ~[dubbo-2.6.0.jar:2.6.0]
    at com.alibaba.dubbo.common.bytecode.proxy0.queryAllStudent(proxy0.java) ~[dubbo-2.6.0.jar:2.6.0]
    at com.test.controller.MyController.List(MyController.java:31) ~[classes/:na]
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_161]
    at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_161]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) ~[na:1.8.0_161]
    at java.lang.reflect.Method.invoke(Unknown Source) ~[na:1.8.0_161]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:90) ~[spring-boot-actuator-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:93) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:155) ~[spring-boot-actuator-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:123) ~[spring-boot-actuator-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:108) ~[spring-boot-actuator-2.0.4.RELEASE.jar:2.0.4.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.8.RELEASE.jar:5.0.8.RELEASE]
    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:493) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:800) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1471) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source) [na:1.8.0_161]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source) [na:1.8.0_161]
    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.32.jar:8.5.32]
    at java.lang.Thread.run(Unknown Source) [na:1.8.0_161]

解决问题：

1.关闭电脑中的WIFI热点。

原因：小编上网连接了手机热点，开启项目后就报错了。之前未使用热点时，项目可以启动起来的。

使用WIFI,机器的IP发生改变。所以在代码没有问题的情况下，要注意WIFL是否开启。