DVD管理系统

import java.util.*;
import java.text.*;

class DVD {
public static long charge(String dstr1,String dstr2){
long charge=0;
SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd");
try {
Date d1 = sd.parse(dstr1);
Date d2 = sd.parse(dstr2);
charge = (d2.getTime() - d1.getTime()) / (24 * 60 * 60 * 1000);
} catch (ParseException e) {
e.printStackTrace();
}
return charge;
}
public static void main(String[] args) {
Scanner input = new Scanner(System.in);

boolean flag = false;

// DVD名称
String[] names = new String[100];

int[] states = new int[20];
// DVD借出日期
String[] dates = new String[20];
// DVD借出次数
int[] count = new int[20];

// 初始化数据
names[0] = "罗马假日";
states[0] = 1;
dates[0] = "2015-10-11";
count[0] = 18;

names[1] = "风声鹤唳";
states[1] = 0;
count[1] = 5;

names[2] = "浪漫满屋";
states[2] = 0;
count[2] = 40;

int num = -1;

do {
// 主菜单显示
System.out.println("欢迎使用DVD管理器");
System.out.println("*-----------------*");
System.out.println("|   1、新增DVD    |");
System.out.println("*-----------------*");
System.out.println("|   2、查看DVD    |");
System.out.println("*-----------------*");
System.out.println("|   3、删除DVD    |");
System.out.println("*-----------------*");
System.out.println("|   4、借出DVD    |");
System.out.println("*-----------------*");
System.out.println("|   5、归还DVD    |");
System.out.println("*-----------------*");
System.out.println("|   6、退出DVD    |");
System.out.println("*-----------------*");
System.out.print("请输入所选：");
int choice = input.nextInt();
switch (choice) {
case 1:
// 新增
System.out.println("---- 新增DVD ----");
System.out.print("请输入DVD名称：");
String name = input.next();
// 标识能否插入 false:不能插入 true:能插入
boolean flag1 = false;

for (int i = 0; i < names.length; i++) {
// 插入DVD
if (names[i] == null) {
names[i] = name;
flag1 = true;
break;
}
}
if (flag1) {
System.out.println("新增《" + name + "》成功！");
} else {
System.out.println("货架已满,不能新增！");
}
break;
case 2:
// 查看
System.out.println("---- 查看DVD -----");
System.out.println("序号\t" + "状态\t" + "名称\t\t" + "借出日期" + "\t借出次数");
for (int i = 0; i < names.length; i++) {
if (names[i] != null) {
String state = (states[i] == 0) ? "可借" : "已借出";
String dateStr = (dates[i] == null) ? "\t" : (dates[i]);
String countStr = (count[i] == 0) ? "\t" : (count[i] + "次");

System.out.println(" " + (i + 1) + "\t" + state + "\t" + names[i] + "\t" + dateStr + "\t" + countStr);
}
}
break;
case 3:

4000
// 删除
System.out.println("---- 删除DVD -----");
System.out.print("请输入要删除的DVD名称：");
String delete = input.next();

boolean flag2 = false;
// 记录要删除的DVD位置
int index = -1;
// 找到要删除DVD的位置
for (int i = 0; i < names.length; i++) {
if (names[i] != null && delete.equals(names[i]) && states[i] == 1) {

flag2 = true;
System.out.println("该DVD已经借出，无法删除！");
break;
} else if (names[i] != null && delete.equals(names[i]) && states[i] == 0) {

flag2 = true;
index = i;
System.out.println("删除《" + delete + "》成功！");
break;
}

}
// 找到DVD删除
if (index != -1) {
// 根据上一步找到的下标位置index
for (int j = index; j < names.length; j++) {

if (j != names.length - 1) {
names[j] = names[j + 1];
states[j] = states[j + 1];
dates[j] = dates[j + 1];
count[j] = count[j + 1];

}
names[names.length - 1] = null;
states[names.length - 1] = 0;
dates[names.length - 1] = null;
count[names.length - 1] = 0;

}
}
if (!flag2) {
System.out.println("对不起，没有匹配的DVD信息，无法删除！");
}
break;
case 4:
// 借出
System.out.print("请输入要借阅的DVD名称：");
String want = input.next();
for (int i = 0; i <= names.length; i++) {
if (names[i] == null) {
System.out.println("没有找到匹配的DVD信息！");
break;
} else if (want.equals(names[i]) && states[i] == 1) {
System.out.println("《" + want + "》已被借出！");
break;
} else if (want.equals(names[i]) && states[i] == 0) {
System.out.print("请输入借出日期(年-月-日)：");
dates[i] = input.next();
states[i] = 1;
count[i]++;
System.out.println("借出《" + want + "》成功！");
break;
}
}

break;
case 5:
// 归还
System.out.print("请输入要归还的DVD名称：");
String back = input.next();
for (int i = 0; i <= names.length; i++) {
if (names[i] == null) {
System.out.println("没有找到匹配的DVD信息");
break;
} else if (back.equals(names[i]) && states[i] == 0) {
System.out.println(back + "未被借出，无需归还！");
break;
} else if (back.equals(names[i])  && states[i] == 1) {
System.out.print("请输入归还日期(年-月-日)：");
// 记录归还日期
String backDate = input.next();

states[i] = 1;
count[i]++;
System.out.println("《" + back + "》归还成功！");
System.out.println("《" + back + "》借阅日期：" + dates[i]);
System.out.println("《" + back + "》归还日期：" + backDate);
long day = charge(dates[i],backDate);
// 计算租金:1元/天
long money = day * 1;
//System.out.println("**********"+aa);
System.out.println("《" + back + "》应付租金：" + money + "元");

// 数据更新
states[i] = 0;
dates[i] = null;
break;
}
}

break;
case 6:
// 退出
flag = true;
break;
default:
// 输入要求以外的数字，默认退出
flag = true;
break;
}
if (flag) {
// 想退出菜单
num = -1;
break;

} else {
// 不退出，继续进行主菜单选择
System.out.println("*-*-*-*-*-*-*-*-*-*-*-*-*");
System.out.println("请输入0返回：");
num = input.nextInt();
}
} while (num == 0);
// 程序退出，结束
System.out.println("谢谢使用本系统！");
}
}