大二小学期java：图书管理系统

大二小学期java：图书管理系统

import java.util.*;

import java.text.*;

public class library {
	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);
		String [] name = new String[55];
		int cnt = 0;
		String [] status = new String[55];
		String [] date = new String[55];
		int [] ifdel = new int[55];
		int [] rank = new int [55];
		status[0] = "已借出";
		name[0] = "《数据结构》";
		date[0] = "2018-7-1";
		status[1] = "可借";
		name[1] = "《数据库》";
		date[1] = "";
		status[2] = "可借";
		name[2] = "《离散数学》";
		date[2] = "";
		cnt = 3;
		int flag = 0;
		int num;
		do {
			System.out.println("欢迎使用图书借阅系统");
			System.out.println("--------------------------");
			System.out.println("0.借出排行榜\t");
			System.out.println("1.新增图书\t");
			System.out.println("2.查看图书\t");
			System.out.println("3.删除图书\t");
			System.out.println("4.借出图书\t");
			System.out.println("5.归还图书\t");
			System.out.println("6.退出\t");
			System.out.println("--------------------------");
			System.out.print("请选择：");
			int choose = input.nextInt();
			switch(choose) {
				case 1:
					System.out.println("--->新增图书\n");
					System.out.print("请输入图书名称：");
					if(cnt==50)System.out.println("图书已满！添加失败！");
					else {
						String newname = input.next();
						name[cnt++] = newname;
						status[cnt-1] = "可借";
						date[cnt-1] = "";
						System.out.println("新增"+name[cnt-1]+"成功！");
						System.out.println("输入0返回：");
					}
					break;
				case 2:
					System.out.println("--->查看图书\n");
					System.out.println("序号\t状态\t名称\t借出日期\t");
					for(int i = 0;i < cnt;i++) {
						System.out.println((i+1)+"\t"+status[i]+"\t"+name[i]+"\t"+date[i]);
					}
					System.out.println("***********************");
					System.out.println("输入0返回：");
					break;
				case 3:
					System.out.println("--->删除图书\n");
					System.out.print("请输入图书名称：");
					String delname = input.next();
					int idx = 0;
					int f = 0;
					for(int i = 0;i < cnt;i++) {
						if(name[i]==delname) {
							f = 1;
							idx = i;
							break;
						}
					}
					if(f == 0)System.out.println("删除失败！");
					else {
						for(int i = idx;i < cnt - 1;i++) {
							name[i] = name[i + 1];
							status[i] = status[i + 1];
							date[i] = date[i + 1];
						}
						System.out.println("删除"+delname+"成功！");
					}
					System.out.println("*************************");
					break;
				case 4:
					System.out.println("--->借出图书\n");
					System.out.print("请输入图书名称：");
					String broname = input.next();
					System.out.print("借出日期（年-月-日）:");
					String brodate = input.next();
					for(int i = 0;i < cnt;i++) {
						if(name[i]==broname) {
							date[i] = brodate;
							status[i] = "已借出";
							break;
						}
					}
					System.out.println("借出"+broname+"成功！");
					System.out.println("*************************");
					break;
				case 5:
					System.out.println("--->归还图书\n");
					System.out.print("请输入图书名称：");
					String retname = input.next();
					System.out.print("请输入归还日期：");
					String retdate = input.next();
					int ff = 0,fff = 0,idxx = 0;
					long ans = 0;
					for(int i = 0;i < cnt;i++) {
						if(retname == name[i]) {
							ff = 1;
							if(status[i]=="已借出") {
								status[i] = "可借";
								ans = charge(date[i],retdate);
								fff = 1;
								idxx = i;
								break;
							}
						}
					}
					if(ff == 1&&fff == 1) {
						System.out.println("归还"+retname+"成功！");
						System.out.println("借出日期："+date[idxx]);
						System.out.println("归还日期："+retdate);
						System.out.println("应付租金（元）："+ans);
					}
					else if(ff == 1&&fff == 0) {
						System.out.println("该图书没有被借出！");
					}
					else {
						System.out.println("没有找到匹配信息！");
					}
					System.out.println("*************************");
					break;
				case 6:
					break;
			}	
			num = input.nextInt();
		}while(num==0);
		System.out.println("欢迎下次使用！");
	}
}