FamilyAccount主函数实现
public class FamilyAccount {public static void main(String[] args){String details="收支\t账户余额\t收支余额\t说 明\n";int balance = 10000;boolean LoopFlag = true;do {System.out.println("\n----------家庭收支记账软件----------\n");System.out.println(" 1.收支明细");System.out.println(" 2.登记收入");System.out.println(" 3.登记支出");System.out.println(" 4.退 出");System.out.println();System.out.println(" 请选择(1-4):");char key = Utility.readMenuSelection();System.out.println();switch(key){case '1':System.out.println("------收支明细--------");System.out.println(details);System.out.println("---------------------");break;case '2':System.out.println("------登记收入---------");System.out.print("请输入收入金额：");int amount1 = Utility.readNumber();System.out.print("请输入收入说明：");String info1 = Utility.readString();balance += amount1;details += "收入" + "\t" + balance + "\t" + amount1 + "\t" + info1 + "\n";System.out.println("---------登记成功---------");break;case '3':System.out.println("------登记支出------");System.out.print("请输入支出金额：");int amount2 = Utility.readNumber();System.out.print("请输入支出说明：");String info2 = Utility.readString();if(balance < amount2){System.out.println("---------余额不足---------");}else{balance -= amount2;details += "支出" + "\t" + balance + "\t" + amount2 + "\t" + info2 + "\n";System.out.println("---------登记成功---------");}break;case '4':System.out.println("确认是否退出(Y/N)？");char yn = Utility.readConfirmSelection();if(yn == 'Y'){LoopFlag = false;}break;}}while(LoopFlag);}
}
Utility类方法的实现
import java.util.Scanner;
public class Utility {public static Scanner scanner = new Scanner(System.in);/**用于界面菜单的选择。该方法读取键盘，如果用户键入’1’-’4’中的任意字符，则方法返回。返回值为用户键入字符。*/public static char readMenuSelection() {char c;for(;;){String str = readKeyBoard(1);// read one characterc = str.charAt(0);if(c != '1' && c != '2' && c != '3' && c != '4' ){System.out.println("选择错误，请重新输入");}else{break;}}return c;}/**用于收入和支出金额的输入。该方法从键盘读取一个不超过4位长度的整数，并将其作为方法的返回值。*/public static int readNumber(){int n;for(;;){String str = readKeyBoard(4);// read one charactertry{n = Integer.parseInt(str);break;}catch(NumberFormatException e){System.out.println("数字输入错误，请重新输入");}}return n;}/**用于收入和支出说明的输入。该方法从键盘读取一个不超过8位长度的字符串，并将其作为方法的返回值。*/public static String readString(){String str = readKeyBoard(8);return str;}/**用于确认选择的输入。该方法从键盘读取‘Y’或’N’，并将其作为方法的返回值。*/public static char readConfirmSelection() {char c;for(;;){String str = readKeyBoard(1);// read one characterc = str.charAt(0);if(c != 'Y' || c != 'N' ){break;}else {System.out.println("选择错误，请重新输入");}}return c;}
Utiprivate static String readKeyBoard(int limit){String line = "";while(scanner.hasNext()){line = scanner.nextLine();if(line.length() < 1||line.length() > limit){System.out.println("输入长度超出限制，请重新输入");continue;}break;}return line;}
}