zhanghu.java

java的一个课程设计 在JAVA上模拟ATM 代码不大 还算不错

import java.sql.*;
import java.io.*;


public class Zhanghu 
{
	
	Ku das=new Ku();




   public int changePwd(String gid,String pwd,String oldPwd,String newPwd,String newPwd2) 
   {
			 if(newPwd.length()==0 || newPwd.trim().equals("")) return -3;//新密码不能为空
			 else if(oldPwd.equals(pwd))
			 {
			 		if(newPwd.equals(newPwd2))
			 		{
			 			das.exeSql("update guest set pwd='"+newPwd+"' where gid='"+gid+"'");
			 			return 1;//密码修改成功
			 		}
			 		else
			 		{
			 			return -2;//两次输入不同
			 		} 		
			 		
			 }
			 else
			 {
			 		return -1;//旧密码输入错误
			 }			 		 	
	 }
   




   public boolean checkZhanghu(String tid) 
   {
     String ssql;     
     ssql="select * from guest where gid='"+tid+"'";     
     if(das.getRowcount(ssql)>0)//合法ID
     {
     	 return true;
     }
     else//非法ID
     {
     	 return false;
     }
   }
   




   public boolean checkPwd(String tid,String tpwd) 
   {
     String ssql;
     ssql="select * from guest where pwd='"+tpwd+"' and gid='"+tid+"'";
     if(das.getRowcount(ssql)>0)//合法pwd
     {
     	 return true;
     }
     else//非法pwd
     {
     	 return false;
     }
   }




	 public float queryBalance(String gid)
	 {
	 	 ResultSet rs;
	 	 String ssql="select * from guest where gid='"+gid+"'";
	 	 float balance=0;
	 	 try
	 	 {
	 	 	 rs=das.getData(ssql);
	 	 	 rs.next();
	 	 	 balance=rs.getFloat("gmoney");
	 	 }
	 	 catch(Exception e)
	 	 {
	 	 	 System.out.println(e.toString());
	 	 }
	 	 finally
	 	 {
	 	 	 return balance;
	 	 }
	 	 
	 }
	 




   public boolean reduceMoney(String tgid,float money) 
   {
     String ssql;
     if(this.queryBalance(tgid)<money) return false;     
     ssql="update guest set gmoney=gmoney-"+money+" where gid='"+tgid+"'";
     if(das.exeSql(ssql)) return true; //取款成功			
   	 else return false; //取款未成功    
   }
   
  protected void finalize()//析构函数
	{
		das.finalize();
	}   
   
}