discard connection
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

The last packet successfully received from the server was 1,210,878 milliseconds ago.  The last packet sent successfully to the server was 0 milliseconds ago.
    at sun.reflect.GeneratedConstructorAccessor172.newInstance(Unknown Source) 
 
~[?:?]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) ~[?:1.8.0_131]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:423) ~[?:1.8.0_131]
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:404) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:
 
983) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3457) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3357) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:
 
3797) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2470) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2617) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2546) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2504) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1370) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.alibaba.druid.pool.DruidPooledStatement.executeQuery(DruidPooledStatement.java:138) [druid-1.0.24.jar!/:1.0.24]
    at org.springframework.jdbc.core.JdbcTemplate$1QueryStatementCallback.doInStatement(JdbcTemplate.java:458) [spring-jdbc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:408) [spring-jdbc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474) [spring-jdbc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484) [spring-jdbc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.boot.actuate.health.DataSourceHealthIndicator.doDataSourceHealthCheck(DataSourceHealthIndicator.java:111) [spring-boot-actuator-1.4.7.RELEASE.jar!/:1.4.7.RELEASE]
    at org.springframework.boot.actuate.health.DataSourceHealthIndicator.doHealthCheck(DataSourceHealthIndicator.java:100) [spring-boot-actuator-1.4.7.RELEASE.jar!/:1.4.7.RELEASE]
    at org.springframework.boot.actuate.health.AbstractHealthIndicator.health(AbstractHealthIndicator.java:38) [spring-boot-actuator-1.4.7.RELEASE.jar!/:1.4.7.RELEASE]
      ...
    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) [spring-core-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:738) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.framework.adapter.MethodBeforeAdviceInterceptor.invoke(MethodBeforeAdviceInterceptor.java:52) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:168) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.interceptor.ExposeInvocationInterceptor.invoke(ExposeInvocationInterceptor.java:92) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:673) [spring-aop-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    ...
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[?:1.8.0_131]
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[?:1.8.0_131]
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[?:1.8.0_131]
    at java.lang.reflect.Method.invoke(Method.java:498) ~[?:1.8.0_131]
    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:97) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:861) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:687) [javax.servlet-api-3.1.0.jar!/:3.1.0]
    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846) [spring-webmvc-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790) [javax.servlet-api-3.1.0.jar!/:3.1.0]
    at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at org.springframework.boot.web.filter.ApplicationContextHeaderFilter.doFilterInternal(ApplicationContextHeaderFilter.java:55) [spring-boot-1.4.7.RELEASE.jar!/:1.4.7.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    ...
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    ...
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at com.alibaba.druid.support.http.WebStatFilter.doFilter(WebStatFilter.java:83) [druid-1.0.24.jar!/:1.0.24]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at org.springframework.boot.actuate.trace.WebRequestTraceFilter.doFilterInternal(WebRequestTraceFilter.java:105) [spring-boot-actuator-1.4.7.RELEASE.jar!/:1.4.7.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at org.springframework.boot.actuate.autoconfigure.MetricsFilter.doFilterInternal(MetricsFilter.java:106) [spring-boot-actuator-1.4.7.RELEASE.jar!/:1.4.7.RELEASE]
    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) [spring-web-4.3.9.RELEASE.jar!/:4.3.9.RELEASE]
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:61) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:285) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:264) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:175) [undertow-servlet-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.server.Connectors.executeRootHandler(Connectors.java:209) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:802) [undertow-core-1.3.28.Final.jar!/:1.3.28.Final]
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142) [?:1.8.0_131]
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) [?:1.8.0_131]
    at java.lang.Thread.run(Thread.java:748) [?:1.8.0_131]
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
    at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:2949) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3367) ~[mysql-connector-java-5.1.37.jar!/:5.1.37]
    ... 104 more

https://blog.csdn.net/zhangbiaobiaobiao/article/details/17077601

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