java - 在 000webhost 连接 mysql 时出现异常

Question

我已经在 000webhost.com 上创建了一个数据库，现在我尝试通过 java 连接到数据库:

Class.forName("com.mysql.jdbc.Driver");
Connection conn = DriverManager.getConnection("jdbc:mysql://mysql14.000webhost.com/a2509514_Email", username, pass);

但是当我执行它时，我收到以下异常:

com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 
** BEGIN NESTED EXCEPTION ** 

java.net.ConnectException
MESSAGE: Connection timed out: connect

STACKTRACE:

java.net.ConnectException: Connection timed out: connect
at java.net.PlainSocketImpl.socketConnect(Native Method)
at java.net.PlainSocketImpl.doConnect(PlainSocketImpl.java:333)
at java.net.PlainSocketImpl.connectToAddress(PlainSocketImpl.java:195)
at java.net.PlainSocketImpl.connect(PlainSocketImpl.java:182)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:366)
at java.net.Socket.connect(Socket.java:525)
at java.net.Socket.connect(Socket.java:475)
at java.net.Socket.<init>(Socket.java:372)
at java.net.Socket.<init>(Socket.java:215)
at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:256)
at com.mysql.jdbc.MysqlIO.<init>(MysqlIO.java:271)
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2771)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at trapack.Experiment.sample(Experiment.java:20)
at trapack.Experiment.main(Experiment.java:35)


** END NESTED EXCEPTION **



Last packet sent to the server was 0 ms ago.
at com.mysql.jdbc.Connection.createNewIO(Connection.java:2847)
at com.mysql.jdbc.Connection.<init>(Connection.java:1555)
at com.mysql.jdbc.NonRegisteringDriver.connect(NonRegisteringDriver.java:285)
at java.sql.DriverManager.getConnection(DriverManager.java:582)
at java.sql.DriverManager.getConnection(DriverManager.java:185)
at trapack.Experiment.sample(Experiment.java:20)
at trapack.Experiment.main(Experiment.java:35)

没有关于这个特定主题的直接讨论，因此我们将非常感谢任何帮助。

Answer 1

我在AWS(Amazon Web Services - 云计算)中使用MySQL时遇到了类似的问题

我必须在站点 (AWS) 中授予我的计算机 IP 权限。

我建议您使用http://www.heidisql.com/测试是否可以连接到 000webhost 中的数据库。如果成功，则错误出在您的 Java 代码中，如果连接失败，则可能是您的凭据、主机站点的安全配置或只是您那里的可怕连接链接。

向我们提供有关您问题的更多信息，以便我们为您提供帮助。