因此REST服务可以正常工作，但是在多个请求（大约10个）之后，下一个请求出现错误。谁能帮我不知道该怎么办？
编辑：9个请求成功，但第10个请求不成功。
错误消息：
2018-06-22 01:52:56.892 ERROR 1716 --- [nio-8080-exec-1] o.h.engine.jdbc.spi.SqlExceptionHelper : HikariPool-1 - Connection is not available, request timed out after 30015ms.
2018-06-22 01:52:57.114 ERROR 1716 --- [nio-8080-exec-1] o.a.c.c.C.[.[.[/].[dispatcherServlet] : Servlet.service() for servlet [dispatcherServlet] in context with path [] threw exception [Request processing failed; nested exception is javax.persistence.PersistenceException: org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection] with root cause
java.sql.SQLTransientConnectionException: HikariPool-1 - Connection is not available, request timed out after 30015ms.
at com.zaxxer.hikari.pool.HikariPool.createTimeoutException(HikariPool.java:667) ~[HikariCP-2.7.8.jar:na]
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:183) ~[HikariCP-2.7.8.jar:na]
at com.zaxxer.hikari.pool.HikariPool.getConnection(HikariPool.java:148) ~[HikariCP-2.7.8.jar:na]
at com.zaxxer.hikari.HikariDataSource.getConnection(HikariDataSource.java:128) ~[HikariCP-2.7.8.jar:na]
at org.hibernate.engine.jdbc.connections.internal.DatasourceConnectionProviderImpl.getConnection(DatasourceConnectionProviderImpl.java:122) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.internal.NonContextualJdbcConnectionAccess.obtainConnection(NonContextualJdbcConnectionAccess.java:35) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.acquireConnectionIfNeeded(LogicalConnectionManagedImpl.java:106) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.resource.jdbc.internal.LogicalConnectionManagedImpl.getPhysicalConnection(LogicalConnectionManagedImpl.java:136) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.connection(StatementPreparerImpl.java:47) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:145) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:171) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:147) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1985) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1915) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1893) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.doQuery(Loader.java:938) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:341) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.doList(Loader.java:2692) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.doList(Loader.java:2675) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2507) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.Loader.list(Loader.java:2502) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:502) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:392) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1489) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1445) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1414) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at org.hibernate.query.Query.getResultList(Query.java:146) ~[hibernate-core-5.2.16.Final.jar:5.2.16.Final]
at jovan.sf_62_2017.postsportal.services.implementations.PostsService.get(PostsService.java:26) ~[classes/:na]
at jovan.sf_62_2017.postsportal.services.implementations.PostsService$$FastClassBySpringCGLIB$$58994bcd.invoke() ~[classes/:na]
at org.springframework.cglib.proxy.MethodProxy.invoke(MethodProxy.java:204) ~[spring-core-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$CglibMethodInvocation.invokeJoinpoint(CglibAopProxy.java:747) ~[spring-aop-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:163) ~[spring-aop-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:294) ~[spring-tx-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:98) ~[spring-tx-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:185) ~[spring-aop-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.aop.framework.CglibAopProxy$DynamicAdvisedInterceptor.intercept(CglibAopProxy.java:689) ~[spring-aop-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at jovan.sf_62_2017.postsportal.services.implementations.PostsService$$EnhancerBySpringCGLIB$$2f5f4fa8.get() ~[classes/:na]
at jovan.sf_62_2017.postsportal.controllers.PostController.get(PostController.java:23) ~[classes/:na]
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) ~[na:1.8.0_162]
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) ~[na:1.8.0_162]
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) ~[na:1.8.0_162]
at java.lang.reflect.Method.invoke(Method.java:498) ~[na:1.8.0_162]
at org.springframework.web.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:209) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:102) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:877) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:783) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:87) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:991) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:925) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:974) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:866) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:635) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:851) ~[spring-webmvc-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at javax.servlet.http.HttpServlet.service(HttpServlet.java:742) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:231) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52) ~[tomcat-embed-websocket-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:158) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.filterAndRecordMetrics(WebMvcMetricsFilter.java:126) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.boot.actuate.metrics.web.servlet.WebMvcMetricsFilter.doFilterInternal(WebMvcMetricsFilter.java:111) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.boot.actuate.web.trace.servlet.HttpTraceFilter.doFilterInternal(HttpTraceFilter.java:84) ~[spring-boot-actuator-2.0.1.RELEASE.jar:2.0.1.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.web.filter.RequestContextFilter.doFilterInternal(RequestContextFilter.java:99) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.web.filter.HttpPutFormContentFilter.doFilterInternal(HttpPutFormContentFilter.java:109) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.web.filter.HiddenHttpMethodFilter.doFilterInternal(HiddenHttpMethodFilter.java:81) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.springframework.web.filter.CharacterEncodingFilter.doFilterInternal(CharacterEncodingFilter.java:200) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.springframework.web.filter.OncePerRequestFilter.doFilter(OncePerRequestFilter.java:107) ~[spring-web-5.0.5.RELEASE.jar:5.0.5.RELEASE]
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198) ~[tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.coyote.http11.Http11Processor.service(Http11Processor.java:803) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459) [tomcat-embed-core-8.5.29.jar:8.5.29]
at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49) [tomcat-embed-core-8.5.29.jar:8.5.29]
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) [na:1.8.0_162]
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) [na:1.8.0_162]
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61) [tomcat-embed-core-8.5.29.jar:8.5.29]
at java.lang.Thread.run(Thread.java:748) [na:1.8.0_162]