Tomcat/Hibernate 与 MySql 的连接失败 "Communications link failure" & "Permission denied"
Tomcat/Hibernate connection to MySql fails with "Communications link failure" & "Permission denied"
我正在尝试使用 Hibernate 从 tomcat 网络应用程序连接到本地主机（我们称之为 A）上的 MySql (=MariaDB)，但一直在获取通信 link失败（下面附有完整的异常跟踪）。
我在另一台机器上有另一个数据库副本（我们称之为 B）并且还使用第三台计算机进行开发（我们称之为 C）。
1) 我从 C 连接到任何一个数据库（A 和 B）都没有问题。
2) 在 "A" 上，我可以在本地连接到数据库（运行 'mysql -u' 命令）。我在端口 3306 上对 A 或 B 进行远程登录也没有问题。所以我假设两个数据库都已启动并且 运行 并且可用于连接。
唯一的问题是当我尝试从生产 tomcat（A 上的 运行）连接到 A 或 B 数据库时。我收到错误：
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
从类似的错误案例中，我发现大多数错误是由于无效的 user/pass 凭据或非法 IP。我还尝试将 ip 更改为 localhost 、 127.0.0.1 和 10.90.41.155 （这是机器的实际 ip）。没有任何帮助，同时请记住，连接仅在 A 上的特定 tomcat 安装失败。
我还尝试了以下方法：
1) 添加“-Djava.net.preferIPv4Stack=true”到catalina启动
2) 试图连接到非法 addresses/ports - 这改变了（如预期的那样）最终错误从 "permission denied" 到 "no route to host"。
3) 在我的连接字符串中添加了以下内容："autoReconnect=true&useUnicode=true&createDatabaseIfNotExist=true&characterEncoding=utf-8" - 这导致了同样的错误 ("Attempted reconnect 3 times. Giving up." + "Permission denied (connect failed)"
4）尝试了两个数据库网址。对于使用 localhost、127.0.0.1 和实际 ip 尝试的本地数据库。在连接字符串中尝试使用和不使用“:3306”
附件是 hibernate.cfg 文件 + 异常的完整服务器跟踪：
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</property>
<property name="hibernate.connection.driver_class">
com.mysql.jdbc.Driver
</property>
<!-- Assume test is the database name -->
<property name="hibernate.connection.url">
jdbc:mysql://10.90.41.151/boonder
</property>
<property name="hibernate.connection.username">
root
</property>
<property name="hibernate.connection.password">
XXXXXXXXXX
</property>
<!-- List of XML mapping files -->
<mapping resource="User.hbm.xml"/>
<mapping resource="Issue.hbm.xml"/>
<mapping resource="TraderIssue.hbm.xml"/>
</session-factory>
</hibernate-configuration>
例外情况是：
type Exception report
message Handler dispatch failed; nested exception is java.lang.ExceptionInInitializerError
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.ExceptionInInitializerError
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:982)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.lang.ExceptionInInitializerError
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:54)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:271)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:233)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.hibernate.exception.JDBCConnectionException: Error calling Driver#connect
org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convert(BasicConnectionCreator.java:101)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:123)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:42)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:20)
org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
...
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:166)
com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:58)
com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:853)
com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:440)
com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
...
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
com.mysql.cj.core.exceptions.CJCommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:423)
com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:54)
com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:93)
com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:133)
com.mysql.cj.core.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:149)
com.mysql.cj.mysqla.io.MysqlaSocketConnection.connect(MysqlaSocketConnection.java:83)
com.mysql.cj.mysqla.MysqlaSession.connect(MysqlaSession.java:204)
com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:975)
com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:843)
com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:440)
com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:42)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:20)
org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:109)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:72)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.net.SocketException: Permission denied (connect failed)
java.net.PlainSocketImpl.socketConnect(Native Method)
java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
java.net.Socket.connect(Socket.java:589)
com.mysql.cj.core.io.StandardSocketFactory.connect(StandardSocketFactory.java:202)
com.mysql.cj.mysqla.io.MysqlaSocketConnection.connect(MysqlaSocketConnection.java:57)
com.mysql.cj.mysqla.MysqlaSession.connect(MysqlaSession.java:204)
com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:975)
com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:843)
com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:440)
com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:42)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:20)
org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:109)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:72)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88)
org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:259)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:233)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
...
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.76 logs.
我刚刚也查到了这个问题。我的症状和你的完全一样，我什至试过你试过的东西。总而言之，我的问题只是因为我在带有 SELinux 的 centos 上使用 tomcat。
一些人帮助我诊断使用以下命令查看安全事件以及为什么不允许某些操作：
sudo ausearch -m avc
sudo grep "tcp_socket" /var/log/audit/audit.log | audit2why // translates log into some human readable reasons why the audit record was generated
我看到了像这样的条目：
type=AVC msg=audit(1507861264.561:64750): avc: denied { name_connect
} for pid=1326 comm="java" dest=3306
scontext=system_u:system_r:tomcat_t:s0
tcontext=system_u:object_r:mysqld_port_t:s0 tclass=tcp_socket
Was caused by: Missing type enforcement (TE) allow rule.
You can use audit2allow to generate a loadable module to allow this access.
然后发现这篇关于tomcat和SELinux的文章https://noobient.com/post/165972214381/selinux-woes-with-tomcat-on-centos-74
您可以运行以下命令查看tomcat是否在tomcat_t安全上下文中运行ning。
$ps auxZ | grep tomcat
为了真正确定我的错误是否是 SELinux，我禁用了 SELinux
$ sestatus // shows: SELinux status: enabled
$ sudo vim /etc/selinux/config // set "SELINUX=disabled"
$ sudo shutdown -r now
$ sestatus // shows: SELinux status: disabled
重新启动我的机器，看到 tomcat 现在正在建立出站连接。
太好了，现在我至少知道为什么会这样了。当然，如果您需要 SELinux，禁用它不是解决方案。另一个可能不是解决方案的解决方法是安装 tomcat 而不通过 yum。 Yum 将使用安全上下文安装 tomcat。
我认为现在的行动方案是修改安全上下文或管理 tomcat 的规则集，以允许它建立传出连接。
这个命令解决了我同样的权限问题：
setsebool -P tomcat_can_network_connect_db 1
我正在尝试使用 Hibernate 从 tomcat 网络应用程序连接到本地主机（我们称之为 A）上的 MySql (=MariaDB)，但一直在获取通信 link失败（下面附有完整的异常跟踪）。
我在另一台机器上有另一个数据库副本（我们称之为 B）并且还使用第三台计算机进行开发（我们称之为 C）。
1) 我从 C 连接到任何一个数据库（A 和 B）都没有问题。 2) 在 "A" 上，我可以在本地连接到数据库（运行 'mysql -u' 命令）。我在端口 3306 上对 A 或 B 进行远程登录也没有问题。所以我假设两个数据库都已启动并且 运行 并且可用于连接。
唯一的问题是当我尝试从生产 tomcat（A 上的 运行）连接到 A 或 B 数据库时。我收到错误：
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
从类似的错误案例中，我发现大多数错误是由于无效的 user/pass 凭据或非法 IP。我还尝试将 ip 更改为 localhost 、 127.0.0.1 和 10.90.41.155 （这是机器的实际 ip）。没有任何帮助，同时请记住，连接仅在 A 上的特定 tomcat 安装失败。
我还尝试了以下方法： 1) 添加“-Djava.net.preferIPv4Stack=true”到catalina启动 2) 试图连接到非法 addresses/ports - 这改变了（如预期的那样）最终错误从 "permission denied" 到 "no route to host"。 3) 在我的连接字符串中添加了以下内容："autoReconnect=true&useUnicode=true&createDatabaseIfNotExist=true&characterEncoding=utf-8" - 这导致了同样的错误 ("Attempted reconnect 3 times. Giving up." + "Permission denied (connect failed)" 4）尝试了两个数据库网址。对于使用 localhost、127.0.0.1 和实际 ip 尝试的本地数据库。在连接字符串中尝试使用和不使用“:3306”
附件是 hibernate.cfg 文件 + 异常的完整服务器跟踪：
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration SYSTEM
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="hibernate.dialect">
org.hibernate.dialect.MySQLDialect
</property>
<property name="hibernate.connection.driver_class">
com.mysql.jdbc.Driver
</property>
<!-- Assume test is the database name -->
<property name="hibernate.connection.url">
jdbc:mysql://10.90.41.151/boonder
</property>
<property name="hibernate.connection.username">
root
</property>
<property name="hibernate.connection.password">
XXXXXXXXXX
</property>
<!-- List of XML mapping files -->
<mapping resource="User.hbm.xml"/>
<mapping resource="Issue.hbm.xml"/>
<mapping resource="TraderIssue.hbm.xml"/>
</session-factory>
</hibernate-configuration>
例外情况是：
type Exception report
message Handler dispatch failed; nested exception is java.lang.ExceptionInInitializerError
description The server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.web.util.NestedServletException: Handler dispatch failed; nested exception is java.lang.ExceptionInInitializerError
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:982)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.lang.ExceptionInInitializerError
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:54)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.hibernate.service.spi.ServiceException: Unable to create requested service [org.hibernate.engine.jdbc.env.spi.JdbcEnvironment]
org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:271)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:233)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
org.hibernate.exception.JDBCConnectionException: Error calling Driver#connect
org.hibernate.exception.internal.SQLStateConversionDelegate.convert(SQLStateConversionDelegate.java:115)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convert(BasicConnectionCreator.java:101)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.convertSqlException(BasicConnectionCreator.java:123)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:41)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:42)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:20)
org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
...
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
com.mysql.cj.jdbc.exceptions.CommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
com.mysql.cj.jdbc.exceptions.SQLError.createCommunicationsException(SQLError.java:166)
com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:58)
com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:853)
com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:440)
com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
...
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
com.mysql.cj.core.exceptions.CJCommunicationsException: Communications link failure
The last packet sent successfully to the server was 0 milliseconds ago. The driver has not received any packets from the server.
sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
java.lang.reflect.Constructor.newInstance(Constructor.java:423)
com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:54)
com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:93)
com.mysql.cj.core.exceptions.ExceptionFactory.createException(ExceptionFactory.java:133)
com.mysql.cj.core.exceptions.ExceptionFactory.createCommunicationsException(ExceptionFactory.java:149)
com.mysql.cj.mysqla.io.MysqlaSocketConnection.connect(MysqlaSocketConnection.java:83)
com.mysql.cj.mysqla.MysqlaSession.connect(MysqlaSession.java:204)
com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:975)
com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:843)
com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:440)
com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:42)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:20)
org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:109)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:72)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.engine.jdbc.internal.JdbcServicesImpl.configure(JdbcServicesImpl.java:51)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.handleTypes(MetadataBuildingProcess.java:352)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.complete(MetadataBuildingProcess.java:111)
org.hibernate.boot.model.process.spi.MetadataBuildingProcess.build(MetadataBuildingProcess.java:83)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:418)
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:180)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:440)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
root cause
java.net.SocketException: Permission denied (connect failed)
java.net.PlainSocketImpl.socketConnect(Native Method)
java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:350)
java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:206)
java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:188)
java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
java.net.Socket.connect(Socket.java:589)
com.mysql.cj.core.io.StandardSocketFactory.connect(StandardSocketFactory.java:202)
com.mysql.cj.mysqla.io.MysqlaSocketConnection.connect(MysqlaSocketConnection.java:57)
com.mysql.cj.mysqla.MysqlaSession.connect(MysqlaSession.java:204)
com.mysql.cj.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:975)
com.mysql.cj.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:843)
com.mysql.cj.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:440)
com.mysql.cj.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:241)
com.mysql.cj.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:221)
org.hibernate.engine.jdbc.connections.internal.DriverConnectionCreator.makeConnection(DriverConnectionCreator.java:38)
org.hibernate.engine.jdbc.connections.internal.BasicConnectionCreator.createConnection(BasicConnectionCreator.java:58)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.addConnections(PooledConnections.java:123)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:42)
org.hibernate.engine.jdbc.connections.internal.PooledConnections.<init>(PooledConnections.java:20)
org.hibernate.engine.jdbc.connections.internal.PooledConnections$Builder.build(PooledConnections.java:161)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.buildPool(DriverManagerConnectionProviderImpl.java:109)
org.hibernate.engine.jdbc.connections.internal.DriverManagerConnectionProviderImpl.configure(DriverManagerConnectionProviderImpl.java:72)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.configureService(StandardServiceRegistryImpl.java:94)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:242)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.buildJdbcConnectionAccess(JdbcEnvironmentInitiator.java:145)
org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:66)
org.hibernate.engine.jdbc.env.internal.JdbcEnvironmentInitiator.initiateService(JdbcEnvironmentInitiator.java:35)
org.hibernate.boot.registry.internal.StandardServiceRegistryImpl.initiateService(StandardServiceRegistryImpl.java:88)
org.hibernate.service.internal.AbstractServiceRegistryImpl.createService(AbstractServiceRegistryImpl.java:259)
org.hibernate.service.internal.AbstractServiceRegistryImpl.initializeService(AbstractServiceRegistryImpl.java:233)
org.hibernate.service.internal.AbstractServiceRegistryImpl.getService(AbstractServiceRegistryImpl.java:210)
...
org.hibernate.boot.internal.MetadataBuilderImpl.build(MetadataBuilderImpl.java:87)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:691)
org.hibernate.cfg.Configuration.buildSessionFactory(Configuration.java:726)
com.aldondy.boonder.bl.DataSingleton.<init>(DataSingleton.java:48)
com.aldondy.boonder.bl.DataSingleton.instance(DataSingleton.java:74)
com.aldondy.boonder.web.controllers.LoginCtrl.loginInner(LoginCtrl.java:62)
com.aldondy.boonder.web.controllers.LoginCtrl.login(LoginCtrl.java:41)
sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
java.lang.reflect.Method.invoke(Method.java:498)
org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:428)
org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:967)
org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:901)
org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:970)
org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
com.aldondy.boonder.web.controllers.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:27)
org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
note The full stack trace of the root cause is available in the Apache Tomcat/7.0.76 logs.
我刚刚也查到了这个问题。我的症状和你的完全一样，我什至试过你试过的东西。总而言之，我的问题只是因为我在带有 SELinux 的 centos 上使用 tomcat。
一些人帮助我诊断使用以下命令查看安全事件以及为什么不允许某些操作：
sudo ausearch -m avc
sudo grep "tcp_socket" /var/log/audit/audit.log | audit2why // translates log into some human readable reasons why the audit record was generated
我看到了像这样的条目：
type=AVC msg=audit(1507861264.561:64750): avc: denied { name_connect } for pid=1326 comm="java" dest=3306 scontext=system_u:system_r:tomcat_t:s0 tcontext=system_u:object_r:mysqld_port_t:s0 tclass=tcp_socket
Was caused by: Missing type enforcement (TE) allow rule.
You can use audit2allow to generate a loadable module to allow this access.
然后发现这篇关于tomcat和SELinux的文章https://noobient.com/post/165972214381/selinux-woes-with-tomcat-on-centos-74
您可以运行以下命令查看tomcat是否在tomcat_t安全上下文中运行ning。
$ps auxZ | grep tomcat
为了真正确定我的错误是否是 SELinux，我禁用了 SELinux
$ sestatus // shows: SELinux status: enabled
$ sudo vim /etc/selinux/config // set "SELINUX=disabled"
$ sudo shutdown -r now
$ sestatus // shows: SELinux status: disabled
重新启动我的机器，看到 tomcat 现在正在建立出站连接。
太好了，现在我至少知道为什么会这样了。当然，如果您需要 SELinux，禁用它不是解决方案。另一个可能不是解决方案的解决方法是安装 tomcat 而不通过 yum。 Yum 将使用安全上下文安装 tomcat。
我认为现在的行动方案是修改安全上下文或管理 tomcat 的规则集，以允许它建立传出连接。
这个命令解决了我同样的权限问题：
setsebool -P tomcat_can_network_connect_db 1