无法将Java连接到远程Mysql数据库服务器

Question

我在以下站点上使用数据库创建了帐户： byethost

并且我尝试使用当我尝试连接到计算机上的本地数据库时可以使用的代码连接到它。

Main.dataSource.setServerName("sql201.byethost33.com");
    Main.dataSource.setDatabaseName("b33_16132071_pizza_service");
    Main.dataSource.setUser("myuser");
    Main.dataSource.setPassword("mypassword");

    try( Connection connection = Main.dataSource.getConnection() ){
        labStatus.setText("Connection to " + databaseName + " succeed");
        labStatus.setStyle("-fx-text-fill: green");

        showLoginButtons();
    }catch(Exception ex){
        labStatus.setText("Connection to " + databaseName + " failed");
        labStatus.setStyle("-fx-text-fill: red");

        ExceptionDialog exceptionDialog = new ExceptionDialog("Couldn't reach the connection", ex);
        exceptionDialog.show();
    }

我收到此错误：

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.GeneratedConstructorAccessor9.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
    at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:1038)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:338)
    at com.mysql.jdbc.ConnectionImpl.coreConnect(ConnectionImpl.java:2237)
    at com.mysql.jdbc.ConnectionImpl.connectOneTryOnly(ConnectionImpl.java:2270)
    at com.mysql.jdbc.ConnectionImpl.createNewIO(ConnectionImpl.java:2069)
    at com.mysql.jdbc.ConnectionImpl.<init>(ConnectionImpl.java:794)
    at com.mysql.jdbc.JDBC4Connection.<init>(JDBC4Connection.java:44)
    at sun.reflect.GeneratedConstructorAccessor6.newInstance(Unknown Source)
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source)
    at java.lang.reflect.Constructor.newInstance(Unknown Source)
    at com.mysql.jdbc.Util.handleNewInstance(Util.java:389)
    at com.mysql.jdbc.ConnectionImpl.getInstance(ConnectionImpl.java:399)
    at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:325)
    at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:422)
    at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:134)
    at com.mysql.jdbc.jdbc2.optional.MysqlDataSource.getConnection(MysqlDataSource.java:105)
    at controller.MainWindowController.menuItemTestConnectionAction(MainWindowController.java:60)
    at sun.reflect.GeneratedMethodAccessor11.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.Trampoline.invoke(Unknown Source)
    at sun.reflect.GeneratedMethodAccessor1.invoke(Unknown Source)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)
    at java.lang.reflect.Method.invoke(Unknown Source)
    at sun.reflect.misc.MethodUtil.invoke(Unknown Source)
    at javafx.fxml.FXMLLoader$MethodHandler.invoke(Unknown Source)
    at javafx.fxml.FXMLLoader$ControllerMethodEventHandler.handle(Unknown Source)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
    at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
    at javafx.event.Event.fireEvent(Unknown Source)
    at javafx.scene.control.MenuItem.fire(Unknown Source)
    at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.doSelect(Unknown Source)
    at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer.lambda$createChildren$341(Unknown Source)
    at com.sun.javafx.scene.control.skin.ContextMenuContent$MenuItemContainer$$Lambda$348/1546169402.handle(Unknown Source)
    at com.sun.javafx.event.CompositeEventHandler$NormalEventHandlerRecord.handleBubblingEvent(Unknown Source)
    at com.sun.javafx.event.CompositeEventHandler.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.EventHandlerManager.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.CompositeEventDispatcher.dispatchBubblingEvent(Unknown Source)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.BasicEventDispatcher.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventDispatchChainImpl.dispatchEvent(Unknown Source)
    at com.sun.javafx.event.EventUtil.fireEventImpl(Unknown Source)
    at com.sun.javafx.event.EventUtil.fireEvent(Unknown Source)
    at javafx.event.Event.fireEvent(Unknown Source)
    at javafx.scene.Scene$MouseHandler.process(Unknown Source)
    at javafx.scene.Scene$MouseHandler.access$1500(Unknown Source)
    at javafx.scene.Scene.impl_processMouseEvent(Unknown Source)
    at javafx.scene.Scene$ScenePeerListener.mouseEvent(Unknown Source)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$MouseEventNotification.run(Unknown Source)
    at java.security.AccessController.doPrivileged(Native Method)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.lambda$handleMouseEvent$350(Unknown Source)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler$$Lambda$316/1708139015.get(Unknown Source)
    at com.sun.javafx.tk.quantum.QuantumToolkit.runWithoutRenderLock(Unknown Source)
    at com.sun.javafx.tk.quantum.GlassViewEventHandler.handleMouseEvent(Unknown Source)
    at com.sun.glass.ui.View.handleMouseEvent(Unknown Source)
    at com.sun.glass.ui.View.notifyMouse(Unknown Source)
    at com.sun.glass.ui.win.WinApplication._runLoop(Native Method)
    at com.sun.glass.ui.win.WinApplication.lambda$null$145(Unknown Source)
    at com.sun.glass.ui.win.WinApplication$$Lambda$36/2117255219.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)
Caused by: java.net.ConnectException: Connection timed out: connect
    at java.net.DualStackPlainSocketImpl.connect0(Native Method)
    at java.net.DualStackPlainSocketImpl.socketConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connectToAddress(Unknown Source)
    at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
    at java.net.PlainSocketImpl.connect(Unknown Source)
    at java.net.SocksSocketImpl.connect(Unknown Source)
    at java.net.Socket.connect(Unknown Source)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:213)
    at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:297)
    ... 70 more

这是我第二次尝试连接到远程数据库。 第一次使用此站点db4free

我只是用这样的数据：

server: www.db4free.net
database: mydatabase
username: username
password: mypassword

我可以使用上面发布的相同Java代码成功连接...

我看到这两个站点的情况有所不同，所以我不知道自己在做什么错。

也许我应该为dataSource对象设置一些端口或其他东西？ 也许这可以解释一些问题：这是我在db4free的 phpMyAdmin中看到的内容 ，可以毫无问题地连接到数据库：

Database server

Server: 127.0.0.1 via TCP/IP
Server type: MySQL
Server version: 5.6.24 - MySQL Community Server (GPL)
Protocol version: 10
User: pizzaadm4@localhost
Server charset: UTF-8 Unicode (utf8)

这就是我在phpMyAdmin或byethost中看到的无法连接的地方

Database server

Server: sql201.byethost33.com via TCP/IP
Software: Percona Server
Software version: 5.6.22-71.0 - Percona Server (GPL), Release 71.0, Revision 726
Protocol version: 10
User: b33_1613071@192.168.0.6
Server charset: UTF-8 Unicode (utf8)

Answer 1

我想我在网站的控制面板中找到了答案...