从 Eclipse 远程连接到 MySQL 数据库

【问题标题】：Remote connection to a MySQL DB from Eclipse从 Eclipse 远程连接到 MySQL 数据库
【发布时间】：2012-10-24 10:53:34
【问题描述】：

我需要从我的 Eclipse 项目连接到 MySQL 远程数据库。

我以这种方式更改我的 context.xml：

<Resource name="jdbc/aname" auth="Container" type="javax.sql.DataSource"
          maxActive="100" maxIdle="30" maxWait="10000"
          username="userdb" password="pwddb" driverClassName="com.mysql.jdbc.Driver"
          url="jdbc:mysql://ipaddress/dbname" 
          factory="org.apache.tomcat.jdbc.pool.DataSourceFactory" />

我使用 ConnectionPool 并在查找中使用 

DataSource ds = (DataSource)initContext.lookup("java:/comp/env/jdbc/aname");

我没有成功连接到数据库。我得到了这个例外：

Unexpected exception resolving reference
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.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1116)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:344)
at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2332)
at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2369)
at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2153)
at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:792)
at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:47)
at sun.reflect.GeneratedConstructorAccessor22.newInstance(Unknown Source)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:525)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:411)
at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:381)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:305)
at org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:266)
at org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:175)
at org.apache.tomcat.jdbc.pool.ConnectionPool.createConnection(ConnectionPool.java:667)
at org.apache.tomcat.jdbc.pool.ConnectionPool.borrowConnection(ConnectionPool.java:607)
at org.apache.tomcat.jdbc.pool.ConnectionPool.init(ConnectionPool.java:470)
at org.apache.tomcat.jdbc.pool.ConnectionPool.<init>(ConnectionPool.java:135)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.pCreatePool(DataSourceProxy.java:112)
at org.apache.tomcat.jdbc.pool.DataSourceProxy.createPool(DataSourceProxy.java:99)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.createDataSource(DataSourceFactory.java:501)
at org.apache.tomcat.jdbc.pool.DataSourceFactory.getObjectInstance(DataSourceFactory.java:224)
at org.apache.naming.factory.ResourceFactory.getObjectInstance(ResourceFactory.java:143)
at javax.naming.spi.NamingManager.getObjectInstance(NamingManager.java:321)
at org.apache.naming.NamingContext.lookup(NamingContext.java:843)
at org.apache.naming.NamingContext.lookup(NamingContext.java:154)
at org.apache.naming.NamingContext.lookup(NamingContext.java:831)
at org.apache.naming.NamingContext.lookup(NamingContext.java:154)
at org.apache.naming.NamingContext.lookup(NamingContext.java:831)
at org.apache.naming.NamingContext.lookup(NamingContext.java:154)
at org.apache.naming.NamingContext.lookup(NamingContext.java:831)
at org.apache.naming.NamingContext.lookup(NamingContext.java:168)
at org.apache.naming.SelectorContext.lookup(SelectorContext.java:158)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at mypackage.login.LoginValidatorAction.execute(LoginValidatorAction.java:44)
at org.apache.struts.chain.commands.servlet.ExecuteAction.execute(ExecuteAction.java:58)
at org.apache.struts.chain.commands.AbstractExecuteAction.execute(AbstractExecuteAction.java:67)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.net.ConnectException: Connection timed out: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(DualStackPlainSocketImpl.java:69)
at java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:339)
at java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:200)
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:182)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:157)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:391)
at java.net.Socket.connect(Socket.java:579)
at java.net.Socket.connect(Socket.java:528)
at java.net.Socket.<init>(Socket.java:425)
at java.net.Socket.<init>(Socket.java:241)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:257)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:294)
... 61 more

javax.naming.NamingException: 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.
at org.apache.naming.NamingContext.lookup(NamingContext.java:860)
at org.apache.naming.NamingContext.lookup(NamingContext.java:154)
at org.apache.naming.NamingContext.lookup(NamingContext.java:831)
at org.apache.naming.NamingContext.lookup(NamingContext.java:154)
at org.apache.naming.NamingContext.lookup(NamingContext.java:831)
at org.apache.naming.NamingContext.lookup(NamingContext.java:154)
at org.apache.naming.NamingContext.lookup(NamingContext.java:831)
at org.apache.naming.NamingContext.lookup(NamingContext.java:168)
at org.apache.naming.SelectorContext.lookup(SelectorContext.java:158)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at mypackage.login.LoginValidatorAction.execute(LoginValidatorAction.java:44)
at org.apache.struts.chain.commands.servlet.ExecuteAction.execute(ExecuteAction.java:58)
at org.apache.struts.chain.commands.AbstractExecuteAction.execute(AbstractExecuteAction.java:67)
at org.apache.struts.chain.commands.ActionCommandBase.execute(ActionCommandBase.java:51)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.commons.chain.generic.LookupCommand.execute(LookupCommand.java:305)
at org.apache.commons.chain.impl.ChainBase.execute(ChainBase.java:191)
at org.apache.struts.chain.ComposableRequestProcessor.process(ComposableRequestProcessor.java:283)
at org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
at org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:722)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:305)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:210)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:224)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:169)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:472)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:168)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:98)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:927)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:118)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:407)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:987)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:579)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:309)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
at java.lang.Thread.run(Thread.java:722)

编辑

我发现 ny mysql db hosting 不允许来自其网络之外的连接

【问题讨论】：

  • 尝试指定你的mysql端口ind datsource jdbc url
  • @KonstantinV.Salikhov：在 url="jdbc:mysql://ipaddress/dbname" 中？ url="jdbc:mysql://ipaddress:3306/dbname" 例如？我试过了，它不起作用。通过php我成功访问了db，使用那个参数，所以我不认为这是一个端口问题。

标签： java eclipse connection-pooling remote-connection


【解决方案1】：

我建议尝试一个测试项目以确保您可以远程连接。下面是一个应该可以工作的代码示例——您需要指定您的 IP 地址、用户名、密码和您希望连接的数据库名称，我在括号中标记了这些名称。确保 MySQL 数据库的用户名具有远程访问权限（类似于 GRANT ALL PRIVILEGES ON exampledb.* TO username@'%' IDENTIFIED BY 'password'; ）注意，'%' 指定连接可以来自任何 IP -地址。 

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;
import java.sql.Statement;

public class JDBCExample {

public static void main(String[] argv) throws SQLException {

    //-------------------------------------------------------------------------
    System.out.println("-------- MySQL JDBC Connection Testing ------------");

    try {

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

    } catch (ClassNotFoundException e) {

        System.out.println("Where is your MySQL JDBC Driver?");
        e.printStackTrace();
        return;

    }

    System.out.println("MySQL JDBC Driver Registered!");
    Connection connection = null;

    try {
        connection = DriverManager
                .getConnection("jdbc:mysql://192.168.1.8:3306/[DATABASE_NAME_HERE]",
                        "[YOUR_USERNAME]", "[YOUR_PASSWORD]");

    } catch (SQLException e) {
        System.out.println("Connection Failed! Check output console");
        e.printStackTrace();
        return;
    }

    if (connection != null) {
        System.out.println("You made it, take control your database now!");
    } else {
        System.out.println("Failed to make connection!");
    }
    //-------------------------------------------------------------------------

            /*
    Statement stmt = connection.createStatement();
    boolean result = stmt.execute("CREATE TABLE Students " +
            " (student_ID INT UNSIGNED NOT NULL AUTO_INCREMENT, " +
            " PRIMARY KEY (student_ID), firstName varchar(255), " +
            " lastName varchar(255))");
    System.out.println("\tTable creation result: " + result + "\t");
    System.out.println("**Note: The expected result is FALSE");
            */
}
}

编辑：此解决方案适用于使用 InnoDB 引擎在 Linux 服务器上运行的 MySQL 5.5 安装。上面的代码是从 Eclipse 中运行的，其中连接器/J .jar 文件包含在项目属性的构建路径中 - 只是为了澄清。

【讨论】：

  • 测试完成，结果是字符串-------- MySQL JDBC Connection Testing ------------ MySQL JDBC Driver Registered！连接失败！检查输出控制台 com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure 最后一个成功发送到服务器的数据包是 0 毫秒前。驱动没有从服务器收到任何数据包。
  • 您是否有权访问运行 MySQL 数据库的服务器？如果是这样，在命令行运行“mysql --version”并检查发行版号；检查您的 mysql 配置文件 (/etc/mysql/my.cnf) 并确保 mysqld 设置为侦听端口 3306；再次，您需要确保您的 mysql 用户具有远程访问权限。然后尝试“sudo /etc/init.d/mysql restart”重新加载mysql服务器进程。您在与我假设的服务器相同的本地网络上运行所有这些，只是来自不同的机器？
  • 答案是您的最后一个问题...我发现我的 mysql 数据库托管不允许来自其网络之外的连接。谢谢你的建议。我会尝试找出是否支持 ssh 隧道。
猜你喜欢
  • 2020-05-05
  • 1970-01-01
  • 1970-01-01
  • 1970-01-01
  • 2013-08-14
  • 1970-01-01
  • 1970-01-01
  • 2013-05-07
  • 2018-11-24
相关资源
最近更新 更多
热门标签
Java Python linux javascript Mysql C# Docker 算法 前端 SpringBoot Redis Vue spring 设计模式 .net core .net kubernetes c++ 数据库 数据结构 大数据 js 机器学习 微服务 Android Go 程序员 面试 JVM ASP.net core 云原生 人工智能 后端 PHP git CSS golang k8s Nginx Django mybatis 深度学习 多线程 React 架构 devops 爬虫 云计算 Spring Boot LeetCode