解决mysql使用java web程序连接发生异常，数据库连接没问题的异常

我用本地web程序连接腾讯云服务器的数据库，会发生这种情况。异常内容如下

05-22:47:08.709 [http-nio-8080-exec-6] ERROR com.alibaba.druid.pool.DruidDataSource - init datasource errorcom.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failureThe last packet successfully received from the server was 291 milliseconds ago.  The last packet sent successfully to the server was 286 milliseconds ago.    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:989)    at com.mysql.jdbc.ExportControlled.transformSocketToSSLSocket(ExportControlled.java:164)    at com.mysql.jdbc.MysqlIO.negotiateSSLConnection(MysqlIO.java:4901)    at com.mysql.jdbc.MysqlIO.proceedHandshakeWithPluggableAuthentication(MysqlIO.java:1659)    at com.mysql.jdbc.MysqlIO.doHandshake(MysqlIO.java:1226)    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2205)    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2236)    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2035)    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:790)    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)    at java.lang.reflect.Constructor.newInstance(Constructor.java:423)    at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:400)    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:330)    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:148)    at com.alibaba.druid.filter.stat.StatFilter.connection_connect(StatFilter.java:211)    at com.alibaba.druid.filter.FilterChainImpl.connection_connect(FilterChainImpl.java:142)    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1360)    at com.alibaba.druid.pool.DruidAbstractDataSource.createPhysicalConnection(DruidAbstractDataSource.java:1414)    at com.alibaba.druid.pool.DruidDataSource.init(DruidDataSource.java:604)    at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:878)    at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:874)    at com.alibaba.druid.pool.DruidDataSource.getConnection(DruidDataSource.java:97)    at org.springframework.jdbc.datasource.DataSourceTransactionManager.doBegin(DataSourceTransactionManager.java:246)    at org.springframework.transaction.support.AbstractPlatformTransactionManager.getTransaction(AbstractPlatformTransactionManager.java:373)    at org.springframework.transaction.interceptor.TransactionAspectSupport.createTransactionIfNecessary(TransactionAspectSupport.java:447)    at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:277)    at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)    at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)    at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:213)    at com.sun.proxy.$Proxy79.pageList(Unknown Source)    at com.whims.app.web.DemoController.pageList(DemoController.java:52)    at com.whims.app.web.DemoController$$FastClassBySpringCGLIB$$4434faa3.invoke(<generated>)    at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204)    at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:652)    at com.whims.app.web.DemoController$$EnhancerBySpringCGLIB$$b0f3e360.pageList(<generated>)    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)    at java.lang.reflect.Method.invoke(Method.java:498)    at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:205)    at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:133)    at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:116)    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)    at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)    at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)    at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)    at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)    at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)    at org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:648)    at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)    at javax.servlet.http.HttpServlet.service(HttpServlet.java:729)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:230)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at com.whims.app.filter.FrameworkFilter.doFilter(FrameworkFilter.java:27)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:105)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:197)    at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107)    at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:192)    at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:165)    at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)    at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)    at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:474)    at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)    at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:79)    at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)    at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:349)    at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:783)    at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)    at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:798)    at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1434)    at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)    at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)    at java.lang.Thread.run(Thread.java:745)

试了各种方法解决不了问题。后来调试出java web程序连接数据库的url的参数设置问题

url如下：

jdbc:mysql://xxxxxxx:3306/demo?useSSL=true

重点在于“useSSL=true”这里，设置为false或者去掉就可以正常运行.

。