dataaccess.java

利用简单的数据库实现ATM柜员机的基本功能（包括存取款

 
import java.sql.*;
public class dataAccess 
{
   private Connection conn;
   private Statement stmt; 
   public dataAccess() //构造函数设置连接数据库
   {
	  try
	  {
	  	Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
		  String dburl ="jdbc:odbc:driver={Microsoft Access Driver (*.mdb)};DBQ=Data\\atm.mdb";
		  conn=DriverManager.getConnection(dburl);
		  stmt=conn.createStatement();  
	  }
	  catch(Exception e1)
	  {
	  	System.out.println(e1.toString());
	  }    
   }

  public ResultSet getData(String sqlstr)//返回查询的数据集
  {
	  try
	  {
	  	ResultSet rs=this.stmt.executeQuery(sqlstr);
	  	return rs;
	  }
	  catch(Exception e)
	  {
	  	System.out.println(e.toString());
	  	return null;
	  }
  }

  public int getRowcount(String sqlstr)//该方法用于返回某一特定数据集的行数
  {
  	int i=0;
  	try
  	{
	  	ResultSet rs=this.getData(sqlstr);
	  	while(rs.next()) 
	  		i++;
  	}
	catch(Exception e)
	{
		System.out.println(e.toString());
	}
	return i;  	
  }

  public boolean exeSql(String sqlstr)//执行无返回的SQL语句
  {
  	try
  	{
  		stmt.execute(sqlstr);
  		return true;  		
  	}
  	catch(Exception e)
  	{  		
  		System.out.println(e.toString());
  		return false;
  	}
  }
  
  public void sleep(int second)//该方法用于延时
  {
  	try
  	{
  		Thread.sleep(second*1000);
  	}
  	catch(Exception e)
  	{
  		System.out.println(e.toString());
  	}
  }
  
  protected void finalize()
  {
	try
	{
		if(stmt!=null) stmt.close();
		if(conn!=null) conn.close();	
	}
	catch(Exception e)
	{}
  } 
}