JAVA基础教程
JAVA基础教程-项目一家庭记账
Utility工具:
package Project;
import java.util.*;
public class Utility {
private static Scanner scan = 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,则方法但会。返回值为用户键入字符。
*/
public static char readMenuSelection() {
char c;
for(;;){
String str = readKeyBoard(1);
c = str.charAt(0);
if(c != '1' && c != '2' && c != '3' && c != '4') {
System.out.print("选择错误,请重新输入:");
}else break;
}
return c;
}
/*
* 用于收入和指出金额的输入。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(10);
try {
n = Integer.parseInt(str);
break;
}catch (NumberFormatException e) {
System.out.print("数字输入错误,请重新输入:");
}
}
return n;
}
/* 用于收入和指出说明的输入。该方法从键盘读取一个不超过8位厂读的字符串,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).toUpperCase();
c = str.charAt(0);
if(c == 'Y' || c == 'N') {
break;
}else {
System.out.print("选择错误,请重新输入:");
}
}
return c;
}
private static String readKeyBoard(int limit){ //定义readKeyBoard方法,限制输入长度
String line = "";
while (scan.hasNext()){
line = scan.nextLine();
if (line.length() < 1 ||line.length() > limit){
System.out.print("输入长度错误(不大于" + limit +"):");
continue;
}
else break;
}
return line;
}
}
主程序:
package Project;
class FamilyAccount {
public static void main(String[] args) {
boolean isFlag = true;
String details = "收 支\t账户金额\t\t收支金额\t\t说 明\n";
//用于记录用户收入及支出的详情
int balance = 10000;
while(isFlag) {
System.out.println("---------------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 \n");
System.out.print(" 请选择(1-4):");
//获取用户的选择1-4
char selection = Utility.readMenuSelection();
switch(selection) {
case '1':
// System.out.println("1.收支明细");
System.out.println("---------------当前收支明细记录------------------\n");
System.out.println(details + "\n");
System.out.println("------------------------------------------------\n");
break;
case '2':
// System.out.println("2.登记收入");
System.out.print("本次收入金额:");
int money = Utility.readNumber();
System.out.print("本次收入说明:");
String info = Utility.readString();
System.out.println("-------------------登记完成----------------------\n");
//处理balance
balance += money;
//处理details
details += ("收 入\t"+ balance + "\t\t" + money + "\t\t" + info +"\n");
break;
case '3':
// System.out.println("3.登记支出");
System.out.print("本次支出金额:");
int cost = Utility.readNumber();
System.out.print("本次支出说明:");
String information = Utility.readString();
//处理balance
if(balance >= cost) {
balance -= cost;
//处理 details
details += ("支 出\t"+ balance + "\t\t" + cost + "\t\t" + information +"\n");
System.out.println("-------------------登记完成----------------------\n");
}else {
System.out.println("本次支出超过余额:支付失败\n");
System.out.println("-------------------登记失败----------------------\n");
}
break;
case '4':
// System.out.println("4.退 出");
System.out.print("确认是否退出(Y/N):");
char isExit = Utility.readConfirmSelection();
if(isExit == 'Y') {
isFlag = false;
}
}
}
}
}
总结:
其中遇到\t制表符的显示问题,\t是补齐之前的字符位,不够八位则补齐,
多余则再补八位。
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