Azure Java“带有MySQL in-app的Web应用程序”，通信链接无法访问数据库

问题描述 投票：1回答：2

我正在尝试将java spring-mvc Web应用程序部署到azure中，但在连接MySQL应用程序时遇到问题。

部署后，我根据连接字符串更新了我的xml中的主机，端口，用户名和密码

/data/MySQL/MySQL con n str_local dB.txt

对此有何帮助？一个附带问题，任何人如何获取java中的连接字符串？这样如果端口号改变了，就不需要更新xml了。

遇到这个错误：

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.

Web应用程序在我的本地工作正常，能够连接并将数据插入数据库。

欣赏帮助。

java mysql azure spring-mvc azure-web-app-service
2个回答
2
投票

我遇到了类似的问题。最后发现，我必须使用最新版本的MySQL-connector-java jar。我之前使用的是5.1.6版本..升级到5.1.30版本或更高版本后，错误消失了

2
投票

根据您对问题的描述，您似乎已将MySql in-app配置信息写为xml文件中的常量。

但是，重要的是要知道配置参数中的port随着应用程序重新启动而随机变化。所以你需要动态配置connectString。

你可以在你提到的MYSQLCONNSTR_localdb.txt中找到连接的配置信息。实际上，MYSQLCONNSTR_localdb是一个环境变量，你可以通过getEnv方法在Java中获取它。

您可以参考下面的代码动态重新配置MYSQL连接参数。

    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();
    }

希望它能帮到你。

更新答案

请检查在Kudu上的web.config文件中是否配置了<environmentVariable name="JAVA_OPTS" value="-Djava.net.preferIPv4Stack=true" />。

需要为仅提供here的IPv4流量配置容器。

您可以参考此线程Solving a "communications link failure" with JDBC and MySQL中的解决方案，并从here获取有关MySql in-app的更多详细信息。

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