Azure Java“；应用程序中带有MySQL的Web应用程序；与数据库的通信链路出现故障

我正在尝试将java spring mvc web应用程序部署到azure中，但在应用程序中连接MySQL时遇到问题

部署后，我根据中的连接字符串更新了xml中的主机、端口、用户名和密码

/data/mysql/MYSQLCONNSTR_localdb.txt

有什么帮助吗？ 一个附带的问题是，有人知道如何在java中获取连接字符串吗？因此，如果端口号更改，则不需要更新xml

遇到此错误：

Type Exception Report

Message Request processing failed; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure

Description The server encountered an unexpected condition that prevented it from fulfilling the request.

Exception

org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.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.
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:982)
    org.springframework.web.servlet.FrameworkServlet.doPost(FrameworkServlet.java:872)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

org.springframework.jdbc.CannotGetJdbcConnectionException: Could not get JDBC Connection; nested exception is com.mysql.jdbc.exceptions.jdbc4.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.
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:80)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    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.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    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:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

com.mysql.jdbc.exceptions.jdbc4.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.
    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.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2209)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    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.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    java.sql.DriverManager.getConnection(DriverManager.java:664)
    java.sql.DriverManager.getConnection(DriverManager.java:208)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:196)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:159)
    org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    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.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    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:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

com.mysql.jdbc.exceptions.jdbc4.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.
    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.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1074)
    com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:343)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2132)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    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.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    java.sql.DriverManager.getConnection(DriverManager.java:664)
    java.sql.DriverManager.getConnection(DriverManager.java:208)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:196)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:159)
    org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    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.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    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:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Root Cause

java.net.SocketException: Permission denied: connect
    java.net.TwoStacksPlainSocketImpl.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.PlainSocketImpl.connect(PlainSocketImpl.java:172)
    java.net.SocksSocketImpl.connect(SocksSocketImpl.java:392)
    java.net.Socket.connect(Socket.java:589)
    java.net.Socket.connect(Socket.java:538)
    java.net.Socket.<init>(Socket.java:434)
    java.net.Socket.<init>(Socket.java:244)
    com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:253)
    com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:292)
    com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2132)
    com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:776)
    com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:46)
    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.jdbc.Util.handleNewInstance(Util.java:406)
    com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:352)
    com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:284)
    java.sql.DriverManager.getConnection(DriverManager.java:664)
    java.sql.DriverManager.getConnection(DriverManager.java:208)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriverManager(DriverManagerDataSource.java:153)
    org.springframework.jdbc.datasource.DriverManagerDataSource.getConnectionFromDriver(DriverManagerDataSource.java:144)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnectionFromDriver(AbstractDriverBasedDataSource.java:196)
    org.springframework.jdbc.datasource.AbstractDriverBasedDataSource.getConnection(AbstractDriverBasedDataSource.java:159)
    org.springframework.jdbc.datasource.DataSourceUtils.doGetConnection(DataSourceUtils.java:111)
    org.springframework.jdbc.datasource.DataSourceUtils.getConnection(DataSourceUtils.java:77)
    org.springframework.jdbc.core.JdbcTemplate.execute(JdbcTemplate.java:394)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:474)
    org.springframework.jdbc.core.JdbcTemplate.query(JdbcTemplate.java:484)
    jbr.springmvc.dao.UserDaoImpl.validateUser(UserDaoImpl.java:44)
    jbr.springmvc.service.UserServiceImpl.validateUser(UserServiceImpl.java:26)
    jbr.springmvc.controller.LoginController.loginProcess(LoginController.java:28)
    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.method.support.InvocableHandlerMethod.doInvoke(InvocableHandlerMethod.java:221)
    org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest(InvocableHandlerMethod.java:136)
    org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle(ServletInvocableHandlerMethod.java:114)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod(RequestMappingHandlerAdapter.java:827)
    org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal(RequestMappingHandlerAdapter.java:738)
    org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle(AbstractHandlerMethodAdapter.java:85)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:963)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:897)
    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:661)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:846)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:742)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
Note The full stack trace of the root cause is available in the server logs.

类型异常报告
消息请求处理失败；嵌套异常为org.springframework.jdbc.CannotGetJdbcConnectionException:无法获取jdbc连接；嵌套异常为com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信链路故障
说明服务器遇到意外情况，无法满足请求。
例外情况
org.springframework.web.util.NestedServletException:请求处理失败；嵌套异常为org.springframework.jdbc.CannotGetJdbcConnectionException:无法获取jdbc连接；嵌套异常为com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信链路故障
成功发送到服务器的最后一个数据包是0毫秒前的。驱动程序尚未从服务器收到任何数据包。
org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:982）
org.springframework.web.servlet.FrameworkServlet.doPost（FrameworkServlet.java:872）
javaservlet.http.HttpServlet.service（HttpServlet.java:661）
org.springframework.web.servlet.FrameworkServlet.service（FrameworkServlet.java:846）
javaservlet.http.HttpServlet.service（HttpServlet.java:742）
org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）
根本原因
org.springframework.jdbc.CannotGetJdbcConnectionException:无法获取jdbc连接；嵌套异常为com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信链路故障
成功发送到服务器的最后一个数据包是0毫秒前的。驱动程序尚未从服务器收到任何数据包。
org.springframework.jdbc.datasource.DataSourceUtils.getConnection（DataSourceUtils.java:80）
org.springframework.jdbc.core.JdbcTemplate.execute（JdbcTemplate.java:394）
org.springframework.jdbc.core.JdbcTemplate.query（JdbcTemplate.java:474）
org.springframework.jdbc.core.JdbcTemplate.query（JdbcTemplate.java:484）
jbr.springmvc.dao.UserDaoImpl.validateUser（UserDaoImpl.java:44）
jbr.springmvc.service.UserServiceImpl.validateUser（UserServiceImpl.java:26）
jbr.springmvc.controller.LoginController.loginProcess（LoginController.java:28）
sun.reflect.NativeMethodAccessorImpl.invoke0（本机方法）
invoke（NativeMethodAccessorImpl.java:62）
sun.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）
java.lang.reflect.Method.invoke（Method.java:498）
org.springframework.web.method.support.InvocableHandlerMethod.doInvoke（InvocableHandlerMethod.java:221）
org.springframework.web.method.support.InvocableHandlerMethod.invokeForRequest（InvocableHandlerMethod.java:136）
org.springframework.web.servlet.mvc.method.annotation.ServletInvocableHandlerMethod.invokeAndHandle（ServletInvocableHandlerMethod.java:114）
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.invokeHandlerMethod（RequestMappingHandlerAdapter.java:827）
org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerAdapter.handleInternal（RequestMappingHandlerAdapter.java:738）
org.springframework.web.servlet.mvc.method.AbstractHandlerMethodAdapter.handle（AbstractHandlerMethodAdapter.java:85）
org.springframework.web.servlet.DispatcherServlet.doDispatch（DispatcherServlet.java:963）
org.springframework.web.servlet.DispatcherServlet.doService（DispatcherServlet.java:897）
org.springframework.web.servlet.FrameworkServlet.processRequest（FrameworkServlet.java:970）
org.springframework.web.servlet.FrameworkServlet.doPost（FrameworkServlet.java:872）
javaservlet.http.HttpServlet.service（HttpServlet.java:661）
org.springframework.web.servlet.FrameworkServlet.service（FrameworkServlet.java:846）
javaservlet.http.HttpServlet.service（HttpServlet.java:742）
org.apache.tomcat.websocket.server.WsFilter.doFilter（WsFilter.java:52）
根本原因
com.mysql.jdbc.exceptions.jdbc4.CommunicationsException:通信链路故障
成功发送到服务器的最后一个数据包是0毫秒前的。驱动程序尚未从服务器收到任何数据包。
sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法）
sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:62）
sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
newInstance（Constructor.java:423）
com.mysql.jdbc.Util.HandleneInstance（Util.java:406）
com.mysql.jdbc.SQLError.createCommunicationsException（SQLError.java:1074）
com.mysql.jdbc.ConnectionImpl.createNewIO（ConnectionImpl.java:2209）
com.mysql.jdbc.ConnectionImpl.（ConnectionImpl.java:776）
JDBC4Connection（JDBC4Connection.java:46）
sun.reflect.NativeConstructorAccessorImpl.newInstance0（本机方法）
sun.reflect.NativeConstructorAccessorImpl.newInstance（NativeConstructorAccessorImpl.java:62）
sun.reflect.DelegatingConstructorAccessorImpl.newInstance（DelegatingConstructorAccessorImpl.java:45）
newInstance（Constructor.java:423）
com.mysql.jdbc.Util.HandleneInstance（Util.java:406）
com.mysql.jdbc.ConnectionImpl.getInstance（ConnectionImpl.java:352）
com.mysql.jdbc.NonRegisteringDriver.connect（NonRegisteringDriver.java:284）
java.sql.DriverManager.getConnection（DriverManager.java:664）
    String connectString = System.getenv("MYSQLCONNSTR_localdb");

    response.getWriter().append("connectString: " + connectString);

    String database = "";
    String port = "";
    String username = "";
    String password = "";

    String[] strArray = connectString.split(";");
    for (int i = 0; i < strArray.length; i++) {
        String[] paramArray = strArray[i].split("=");
        switch (i) {
        case 0:
            database = paramArray[1];
            continue;
        case 1:
            port = paramArray[1];
            continue;
        case 2:
            username = paramArray[1];
            continue;
        case 3:
            password = paramArray[1];
            continue;
        }
    }

    String url = "jdbc:mysql://" + port + "/" + database + "?"
            + "user=" + username + "&password=" + password + "&useUnicode=true&characterEncoding=UTF8";

    response.getWriter().append("url:" + url);

    try {
        Class.forName("com.mysql.jdbc.Driver");

        Connection conn = DriverManager.getConnection(url);

        response.getWriter().append("     connect success");

        Statement stmt = conn.createStatement();

        String sql = "create table student(NO char(20),name varchar(20),primary key(NO))";

        int result = stmt.executeUpdate(sql);

        response.getWriter().append("     insert result" + result);

    } catch (Exception e) {
        e.printStackTrace();
    }