UnknownHostException：连接到数据库服务器时

Question

我正在尝试在1nd1.com上托管MySQL数据库。 我创建了一个只有几个表的数据库。 从Java应用程序连接到1and1数据库时出现以下错误。

使用“ ping hostname”命令从命令提示符执行ping操作时，响应失败。

有什么方法可以从Java程序连接到该主机吗？

com.mysql.jdbc.CommunicationsException: Communications link failure due to underlying exception: 

** BEGIN NESTED EXCEPTION ** 

java.net.UnknownHostException
MESSAGE: db726853948.db.1and1.com

STACKTRACE:

java.net.UnknownHostException: db726853948.db.1and1.com
    at java.net.Inet6AddressImpl.lookupAllHostAddr(Native Method)
    at java.net.InetAddress$2.lookupAllHostAddr(InetAddress.java:907)
    at java.net.InetAddress.getAddressesFromNameService(InetAddress.java:1302)
    at java.net.InetAddress.getAllByName0(InetAddress.java:1255)
    at java.net.InetAddress.getAllByName(InetAddress.java:1171)
    at java.net.InetAddress.getAllByName(InetAddress.java:1105)
    at com.mysql.jdbc.StandardSocketFactory.connect(StandardSocketFactory.java:246)
    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:664)
    at java.sql.DriverManager.getConnection(DriverManager.java:247)
    at Contct.insertDetails(Contct.java:11)
    at Contct.main(Contct.java:28)

** END NESTED EXCEPTION **
Last packet sent to the server was 0 ms ago.

Answer 1

尝试将主机名添加到主机文件

例如：

your_host_ip(122.2.2.1)     hostname(db726853948.db.1and1.com)