com.microsoft.sqlserver.jdbc.SQLServerException: 通过端口 1433

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;


public class TestJDBC {

    /**
     * @param args
     */
    /**jdbc:sqlserver://localhost:1433;databaseName=bbsDB;user=Lenovo;password=123456"
     * @param args
     */
    public static void main(String[] args)  {
        Connection con=null;
        Statement stmt=null;
        ResultSet rs=null;
        try{
            //jdbc:sqlserver://localhost:1433;databaseName=bbsDB;user=Lenovo;password=123456
            //jdbc:sqlserver://localhost;user=MyUserName;password=*****;
            Class.forName("com.microsoft.sqlserver.jdbc.SQLServerDriver");
            con=DriverManager.getConnection("jdbc:sqlserver://localhost;user=Lenovo;password=123456");
            stmt=con.createStatement();
            rs=stmt.executeQuery("Select * from bbsUsers ");
            while(rs.next()){
                //得到内容
                             rs.getString("UserName");
            }
        }catch(ClassNotFoundException e){
            e.printStackTrace();
        }catch(SQLException e){
            e.printStackTrace();
        }
        finally{
            try{
                if(con!=null){
                    con.close();
                    con=null;
                }
                if(stmt!=null){
                    stmt.close();
                    stmt=null;
                }
                if(rs!=null){
                    rs.close();
                    rs=null;
                }
            }catch(SQLException e){
                e.printStackTrace();
            }
        }
    }
}

com.microsoft.sqlserver.jdbc.SQLServerException: 通过端口 1433 连接到主机 localhost 的 TCP/IP 连接失败。错误:“Connection refused: connect。请验证连接属性，并检查 SQL Server 的实例正在主机上运行，且在此端口接受 TCP/IP 连接，还要确保防火墙没有阻止到此端口的 TCP 连接。”。
    at com.microsoft.sqlserver.jdbc.SQLServerException.makeFromDriverError(SQLServerException.java:171)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.connectHelper(SQLServerConnection.java:1033)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.login(SQLServerConnection.java:817)
    at com.microsoft.sqlserver.jdbc.SQLServerConnection.connect(SQLServerConnection.java:700)
    at com.microsoft.sqlserver.jdbc.SQLServerDriver.connect(SQLServerDriver.java:842)
    at java.sql.DriverManager.getConnection(DriverManager.java:582)
    at java.sql.DriverManager.getConnection(DriverManager.java:207)
    at TestJDBC.main(TestJDBC.java:24)