usephonecard.java

有大量的java的实例

public class UsePhoneCard
{
public static void main(String args[])
{
	PhoneCard myCard = new PhoneCard(12345678,1234,50.0,"300");
	System.out.println(myCard.toString());
}
}
class PhoneCard
{
		long  cardNumber;
		private  int  password;
		double  balance;
		String  connectNumber;
		boolean  connected;

		PhoneCard(long cn, int pw, double b,String s)
		{
			cardNumber = cn;
			password = pw;
			if ( b > 0 )
				balance = b;
			else
				System.exit(1);
			connectNumber = s;
			connected = false;
		}
		boolean performConnection(long cn,int pw)		
		{
			if(cn == cardNumber && pw == password )
			{
				connected = true;
				return true;
			}
			else
			{
				connected = false;
				return false;
			}
		}
		double getBalance()
		{
			if(connected)
				return balance;
			else
				return -1;
		}
		void performDial()
		{
			if(connected)
				balance -= 0.5;
		}
		public String toString()
		{
			String s = "电话卡接入号码："+connectNumber
				+"\n电话卡卡号："+cardNumber
				+"\n电话卡密码："+password
				+"\n剩余金额："+balance;
			if(connected)
				return (s + "\n电话已接通。");
			else
				return (s + "\n电话未接通。");
		}
}