conn.java

里面所含源码是本人平时做程序的一些实例

import java.sql.*;
import javax.swing.JOptionPane;
class Conn{
	Statement stmt;
	public Connection openDatabase(){
		String url="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=HappyChat";
		try{
		Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
		Connection con=DriverManager.getConnection(url,"sa","");
		return con;
		}
		catch(Exception e)
		{
			JOptionPane.showMessageDialog(null,"数据库连接出错!");
			return null;
		}

	}
	public boolean executesql(String sql)
	{
		try{
			//String sql="select * from users where U_Name='mxb' and U_pass='mxb'";
			Statement stmt=openDatabase().createStatement();
			
			ResultSet rs=stmt.executeQuery(sql);
			if(rs.next())
				return true;
			else
			{
				JOptionPane.showMessageDialog(null,"用户名或密码错误!");
				return false;
			}
		}
		catch(Exception e)
		{
			e.printStackTrace();
		}
		finally{
			try{
				if(openDatabase()!=null)
				{
					openDatabase().close();
					
				//	stmt.close();
				}
			}catch(Exception e){
				JOptionPane.showMessageDialog(null,"关闭数据库出错!");
	
			}
			
		}
	
		return false;
	}

}