jdbc连接数据库失败，com.microsoft.sqlserver.jdbc.SQLServerException: 到主机 的 TCP/IP 连接失败。

创建数据库连接失败！

com.microsoft.sqlserver.jdbc.SQLServerException: 到主机 的 TCP/IP 连接失败。 java.net.ConnectException: Connection refused: connect

at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(Unknown Source)

at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(Unknown Source)

at com.microsoft.sqlserver.jdbc.SQLServerConnection.loginWithoutFailover(Unknown Source)

at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(Unknown Source)

at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(Unknown Source)

at java.sql.DriverManager.getConnection(Unknown Source)

at java.sql.DriverManager.getConnection(Unknown Source)

at com.mingrisoft.dao.GetConnection.getCon(GetConnection.java:21)

at com.mingrisoft.dao.UserDao.getUser(UserDao.java:11)

at com.mingrisoft.main.Enter$2.actionPerformed(Enter.java:111)

at javax.swing.AbstractButton.fireActionPerformed(Unknown Source)

at javax.swing.AbstractButton$Handler.actionPerformed(Unknown Source)

at javax.swing.DefaultButtonModel.fireActionPerformed(Unknown Source)

at javax.swing.DefaultButtonModel.setPressed(Unknown Source)

at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(Unknown Source)

at java.awt.Component.processMouseEvent(Unknown Source)

at javax.swing.JComponent.processMouseEvent(Unknown Source)

at java.awt.Component.processEvent(Unknown Source)

at java.awt.Container.processEvent(Unknown Source)

at java.awt.Component.dispatchEventImpl(Unknown Source)

at java.awt.Container.dispatchEventImpl(Unknown Source)

at java.awt.Component.dispatchEvent(Unknown Source)

at java.awt.LightweightDispatcher.retargetMouseEvent(Unknown Source)

at java.awt.LightweightDispatcher.processMouseEvent(Unknown Source)

at java.awt.LightweightDispatcher.dispatchEvent(Unknown Source)

at java.awt.Container.dispatchEventImpl(Unknown Source)

at java.awt.Window.dispatchEventImpl(Unknown Source)

at java.awt.Component.dispatchEvent(Unknown Source)

at java.awt.EventQueue.dispatchEventImpl(Unknown Source)

at java.awt.EventQueue.access$400(Unknown Source)

at java.awt.EventQueue$3.run(Unknown Source)

at java.awt.EventQueue$3.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

at java.awt.EventQueue$4.run(Unknown Source)

at java.awt.EventQueue$4.run(Unknown Source)

at java.security.AccessController.doPrivileged(Native Method)

at java.security.ProtectionDomain$1.doIntersectionPrivilege(Unknown Source)

at java.awt.EventQueue.dispatchEvent(Unknown Source)

at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source)

at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.pumpEvents(Unknown Source)

at java.awt.EventDispatchThread.run(Unknown Source)

源代码是：

public class GetConnection {	
private Connection con;			//定义数据库连接类对象
private PreparedStatement pstm;	
private String user="sa";		//连接数据库用户名
private String password="sa";		//连接数据库密码
private String className="com.microsoft.sqlserver.jdbc.SQLServerDriver";	//数据库驱动
private String url="jdbc:sqlserver://localhost:1433;DatabaseName=db_supermarket";		//连接数据库的URL
public GetConnection(){
	try{
		Class.forName(className);
	}catch(ClassNotFoundException e){
		System.out.println("加载数据库驱动失败！");
		e.printStackTrace();
	}
}
/**创建数据库连接*/
public Connection getCon(){
	try {
		con=DriverManager.getConnection(url,user,password);		//获取数据库连接
	} catch (SQLException e) {
		System.out.println("创建数据库连接失败！");
		con=null;
		e.printStackTrace();
	}
	return con;					//返回数据库连接对象
}

解决方法：

安装SQL Server 2005后。在目录下找到SQL Server Configuration Manager这个工具，然后在左边的目录中找到SQL Server 2005网络配置下的MSSQLSERVER，点击后右侧列出了所有协议，找到TCP/IP，发现是禁用状态，启用后再重启MSSQLSERVER服务即可（此步骤必须！），此项可在该工具下的SQL
Server 2005服务中找到，或在windows服务中找到。