Java MySQL JDBC连接器错误

我正在使用最新的MySQL版本。。。在使用命名管道的java应用程序中，我开始连续20次收到以下错误：

 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 ......
at ......
at ......
at ......
  Caused by: java.io.FileNotFoundException: All pipe instances are busy
... 4 more

 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 ......
at ......
at ......
at ......
  Caused by: java.io.FileNotFoundException: All pipe instances are busy
... 4 more

 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 ......
at ......
at ......
at ......
  Caused by: java.io.FileNotFoundException: All pipe instances are busy
... 4 more

MySQL服务器是活动的，通过命令行和PHP可以正常工作。我使用的是Windows7Ultimate。这个java异常的原因是什么？我如何修复它

谢谢。

检查您的连接字符串（主机名和端口），检查数据库服务器是否已启动并正在运行，检查软件是否阻止连接。。。等等，最后。。。显示您的代码和连接属性。