oracle 11g JDBC连接数据库：IO异常The Network Adapter could not establish the connection 解决方法

	ojdbc5.jar (2,095,932 bytes) - Classes for use with JDK 1.5. It contains the JDBC driver classes, except classes for NLS support in Oracle Object and Collection types.
	ojdbc5_g.jar (3,426,203 bytes) - Same as ojdbc5.jar, except that classes were compiled with "javac -g" and contain tracing code.
	ojdbc6.jar (2,714,189 bytes) - Classes for use with JDK 1.6. It contains the JDBC driver classes except classes for NLS support in Oracle Object and Collection types.
	ojdbc6_g.jar (4,463,274 bytes) - Same as ojdbc6.jar except compiled with "javac -g" and contains tracing code.

Io 异常: The Network
Adapter could not establish the connection

1、IP错误：

在设置URL时错误，例如：jdbc:oracle:thin:@192.168.0.111:1521:disease

数据库服务器是否正确：ping 服务器IP是否通畅。ping不通则将URL更改正确。

端口号是否正确。

进行一下操作：在DOS上键入sqlplus，检查oracle是否开启

一切正常则执行下面。

2、防火墙

如果机器上安装有放火墙，可能是服务器端口号屏蔽而造成的。关闭防火墙后，尝试重新连接。