简单的管理系统

import java.util.*;
import java.text.SimpleDateFormat;
import java.text.ParseException;
class DVDSet
{
	String[] name =new String[50];
	int[] state = new int[50];
	String[] date = new String[50];
	int[] count = new int[50];
}

class DVDMgr
{
	DVDSet dvd = new DVDSet();
	public void initial(){
		dvd.count[0] = 1;
		dvd.name[0] = "语文书";
		dvd.state[0] = 0;
		dvd.date[0] = "2016-11-11";

		dvd.name[1] = "数学书";
		dvd.state[1] = 1;

		dvd.name[2] = "历史书";
		dvd.state[2] = 1;
	}
	
	public void startMenu(){
		Scanner reader = new Scanner(System.in);
		System.out.println("欢迎使用迷你管理器！！！");
		System.out.println("-----------------------------------------");
		System.out.println("0.最新排行榜");
		System.out.println("1.新增");
		System.out.println("2.查看");
		System.out.println("3.删除");
		System.out.println("4.借出");
		System.out.println("5.归还");
		System.out.println("6.退出");
		System.out.println("-----------------------------------------");
		System.out.print("请选择：");
		int choice = reader.nextInt();
		System.out.println();

		switch (choice)
		{
		case 0:
			show();
			returnMain();
			break;
		case 1:
			add();
			returnMain();
			break;
		case 2:
			check();
			returnMain();
			break;
		case 3:
			del();
			returnMain();
			break;
		case 4:
			borrow();
			returnMain();
			break;
		case 5:
			returnDvd();
			returnMain();
			break;
		case 6:
			System.out.println("谢谢光临");
			break;
		default :
			System.out.println("输入有误");
			break;
		}
	}

	public void returnMain(){
		Scanner reader = new Scanner(System.in);
		System.out.print("输入0返回主菜单:");
		if(reader.nextInt() == 0){
			startMenu();
		}
		else{
			System.out.println("请输入0字符号");
		}
	}
	//排行
	public void show(){
		String[] newDvds = new String[50];
		for(int i = 0; i < dvd.name.length; i++){
			newDvds[i] = dvd.name[i];
		}
		int[] newCounts = new int[50];
		for(int i = 0; i < dvd.count.length; i++){
			newCounts[i] = dvd.count[i];
		}
		
		for(int i = 0; i < newDvds.length; i++){
			if(newDvds[i] == null){
				break;
			}
			for(int j = i; j < newDvds.length; j++){
				if(newDvds[j] == null){
				break;
				}
				if(newCounts[i] < newCounts[j]){
					int temp = newCounts[i];
					newCounts[i] = newCounts[j];
					newCounts[j] = temp;

					String str = newDvds[i];
					newDvds[i] = newDvds[j];
					newDvds[j] = str;
				}
			}
		}
		System.out.println("-----------------------------------------");
		System.out.println("次数		名称");
		for(int i = 0; i < newDvds.length; i ++){
			if(newDvds[i] == null){
				break;
			}
			System.out.println(newCounts[i] + "		" + "<<" + newDvds[i] + ">>");
			
		}
		System.out.println("-----------------------------------------");

	}
	//1.新增
	public void add(){
		Scanner reader = new Scanner(System.in);
		for(int i = 0; i < dvd.name.length; i++){
			if(dvd.name[i] == null ){
				System.out.println("请输入要新增的DVD");
				dvd.name[i] = reader.next();
				dvd.state[i] = 1;
				System.out.println("新增成功");
				break;
			}
		}
	}

	//2.查看
	public void check(){
		System.out.println("序号	状态	名称		借出日期");
		for(int i = 0; i < dvd.name.length; i++){
			if(dvd.name[i] == null){
				break;
			}
			if (dvd.state[i] == 1)
			{
				System.out.println( i + "	" + "可借" + "	" + "<<" +dvd.name[i] + ">>" );
			}
			else {
				System.out.println( i + "	" + "不可借" + "  " + "<<" + dvd.name[i] + ">>" + "	" + dvd.date[i]);
			}
		}
	}

	//3.删除
	public void del(){
		Scanner reader = new Scanner(System.in);
		System.out.println("请输入要删除的DVD");
		String name = reader.next();
		for(int i = 0; i < dvd.name.length; i++){
			if(dvd.name[i] == null){
				System.out.println("没有查询到结果");
				break;
			}else if(dvd.name[i].equalsIgnoreCase(name)){
				if(dvd.state[i] == 0){
					System.out.println("<<" + name + ">>借出状态，不可以删除" );
					break;
				}
				else{
					  int j=i;
					  while(dvd.name[j+1]!=null){
						 dvd.name[j]=dvd.name[j+1];
						 dvd.state[j]=dvd.state[j+1];
						 dvd.date[j]=dvd.date[j+1]; 
						 j++;
					  }
				dvd.name[j]=null; 
				dvd.date[j]=null;
                System.out.println("删除《"+name+"》成功！");
				break;
				}
			}
		}
	}

	//4.借出
	public void borrow(){
		Scanner reader = new Scanner(System.in);
		System.out.println("请输入DVD名称");
		String name = reader.next();
		for(int i = 0; i < dvd.name.length;i++){
			if(dvd.name[i] == null){
				System.out.println("未查询到结果！");
				break;
			}
			else if(dvd.name[i].equalsIgnoreCase(name)){
					if(dvd.state[i] == 0){
					System.out.println("该DVD已经借出");
					break;
				}else{
					dvd.state[i] = 0;
					System.out.println("请输入借出的日期");
					dvd.date[i] = reader.next();
					dvd.count[i]++;
					System.out.println("该" + "<<" + dvd.name[i] + ">>" + "DVD已经借出");
					break;
				}		
			}
		}
	}

	//5归还
	public void returnDvd(){
		Scanner reader = new Scanner(System.in);
		System.out.println("欢迎光临");
		String name = reader.next();
		for(int i = 0; i < dvd.name.length;i++){
			if(dvd.name[i] == null){
				System.out.println("未查询到结果");
				break;
			}
			if(dvd.name[i].equalsIgnoreCase(name)){
				if(dvd.state[i] == 1){
					System.out.println("该DVD错误");
				}else{
				System.out.println("输入日期");
				String newDate = reader.next();
				System.out.println("归还" + "<<" + name + ">>" + "成功");
				System.out.println("借出日期为：" + dvd.date[i]);
				System.out.println("归还日期为：" + newDate);
				System.out.println("应付租金（元）" + charge(dvd.date[i],newDate));
				dvd.state[i] = 1;
				break;
				}
			}
		}

	}
	//日期计算 
	public 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; 
	}
	

}


class  MiniDvd
{
	public static void main(String[] args) 
	{
		DVDMgr dm = new DVDMgr();
		dm.initial();
		dm.startMenu();
	}
}