利用所学的集合写出的DVD管理系统，运用到了所学到集合基础。
import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.ArrayList; import java.util.Comparator; import java.util.Date; import java.util.HashSet; import java.util.List; import java.util.Scanner; import java.util.Set; import java.util.TreeSet; import org.omg.CORBA.PUBLIC_MEMBER; import org.w3c.dom.ls.LSInput; class DVDSetcompare implements Comparator{ public int compare(Object o1, Object o2) { DVDSet d1 = (DVDSet)o1; DVDSet d2 = (DVDSet)o2; return d1.count-d2.count; } } class DVDSet { String name;//DVD的名字 int state ;//借出状态：0已借出/1：可借 String date ;//DVD借出日期 int count;//借出次数 public DVDSet(String name,int state, String date, int count){ this.name = name; this.state = state; this.date = date; this.count = count; } public String toString() { // TODO Auto-generated method stub return this.name; } } class DVDMgr{ //创建集合用来存贮对象的信息 List list = new ArrayList<>(); int pas;//记录每次借出的记录次数 private DVDSet DVDSet; public void initial() { list.add(new DVDSet("罗马假日", 0, "2016-2-1", 30)); list.add(new DVDSet("风声鹤唳", 1, null, 50)); list.add(new DVDSet("浪漫满屋", 1, null, 1)); } public void startMenu(){ System.out.println("**************^^^^^^^^^^^*****************"); System.out.println("欢迎使用迷你DVD管理器"); String[] book = {"1.新增DVD","2.查看DVD","3.删除DVD","4.借出DVD","5.归还DVD","6.排行榜","7.退出"}; for(int i = 0; i<book.length;i++){ System.out.println(book[i]); } System.out.println("*******************************"); System.out.print("请选择："); Scanner scan = new Scanner(System.in); int chioce = scan.nextInt(); switch(chioce){ case 1: addDVD(); break; case 2: lookupDVD(); break; case 3: deleteDVD(); break; case 4: lendDVD(); break; case 5: returnDVD(); break; case 6: listDVD(); break; case 7: System.out.println("感谢使用，欢迎您下次使用!!!!!"); break; default:System.out.println("输入错误，异常终止"); } } //*************查看开始*********** public void lookupDVD(){ System.out.println("--->查看DVD "); System.out.println("序号 状态 名称 借出日期"); for(int i = 0;i<list.size();i++){ DVDSet dvd= (DVDSet)list.get(i); if (dvd.state==0) { System.out.println(i+ " " + "已借出" + " " + dvd.name+ " " + dvd.date); } else if (dvd.state==1) { System.out.println(i + " " + "可借" + " " + dvd.name+ " "); } } returnMain(); } //**********返回函数块******* public void returnMain(){ Scanner input = new Scanner(System.in); System.out.print("输入0返回："); if(input.nextInt()==0){ startMenu(); }else{ System.out.println("输入错误，异常终止,请中重新输入"); returnMain(); } } //******************返回函数块结束********* //*************实现增加DVD开始************* public void addDVD(){ Scanner input = new Scanner(System.in); System.out.println("***************>>>>新增DVD "); System.out.println("请输入DVD名称"); String name1 = input.next(); list.add(new DVDSet(name1, 1, null, 0)); System.out.println(name1+"新增成功"); returnMain(); } //*************实现增加DVD结束************* //*************实现删除DVD开始************* public void deleteDVD(){ System.out.println("***************>>>>删除DVD "); System.out.print("请输入你要删除DVD的名称:"); Scanner input =new Scanner(System.in); String name = input.next(); Boolean boolean1 = false; for (int i = 0; i < list.size(); i++) { DVDSet dvdSet = (DVDSet)list.get(i); if ((int)dvdSet.state==0&&dvdSet.name.equals(name)) { System.out.println(dvdSet.name+"已借出无法删除"); deleteDVD(); } else if(dvdSet.name.equals(name)&&dvdSet.state==1){ list.remove(i); boolean1= true; } } if (boolean1) { System.err.println(name+"删除成功"); }else { System.err.println("没有这个DVD，请重亲输入"); deleteDVD(); } System.out.println(); returnMain(); } //*************实现删除DVD结束************* //*************实现借出DVD开始************* public void lendDVD(){ Scanner input = new Scanner(System.in); System.out.println("***************>>>>借出DVD "); System.out.println("请输入你要借的DVD的名称"); String lendname = input.next(); boolean b = false; for (int i = 0; i < list.size(); i++) { DVDSet dvdSet = (DVDSet)list.get(i); if(dvdSet.name.equals(lendname)&&dvdSet.state==1){ System.out.println("请输入借出的日期（年-月-日）"); String date = input.next(); list.set(i, new DVDSet(lendname, 0, date,pas++ )); b=true; }else if(dvdSet.name.equals(lendname)&&(int)dvdSet.state==0){ System.out.println("<<"+lendname+">>已经被借出"); returnMain(); } } if (b==true) { System.out.println("借出<<"+lendname+">>成功！"); }else { System.out.println("找不到该DVD比配的信息"); returnMain(); } returnMain(); } //*************实现借出DVD结束************* //*************实现归还DVD结束************* public void returnDVD(){ Scanner input = new Scanner(System.in); System.out.println("***************>>>>归还DVD "); System.out.println("请输入你要归还的DVD的名称"); String returndvd = input.next(); for(int i =0 ;i<list.size();i++){ DVDSet dvdSet = (DVDSet)list.get(i); if (returndvd.equals(dvdSet.name)&&dvdSet.state==0) { System.out.println("请输入归还的DVD的日期"); String date = input.next(); System.out.println(returndvd+"归还成功！"); System.out.println("借出日期为:" + dvdSet.date); System.out.println("归还日期为:" + date); //计算归还的本金 String d1 =dvdSet.date;//第一个日期 String d2 = date;//第二个日期 long charge = 0; SimpleDateFormat sd = new SimpleDateFormat("yyyy-MM-dd"); try{ Date D1 = sd.parse(d1); Date D2 = sd.parse(d2); charge = ((D2.getTime()-D1.getTime())/(24*60*60*1000))/10; }catch(ParseException e){ e.printStackTrace(); } list.set(i, new DVDSet(returndvd,1, null, 1)); System.out.println("应付租金:" + charge + "元"); break; }else if(dvdSet.name.equals(returndvd)&&dvdSet.state==1) { System.out.println("这DVD没有被借出，无需归还"); break; }/*else if (dvdSet.name!=returndvd) { System.out.println("这DVD没有"); break; } */ } returnMain(); } //*************实现归还DVD结束************* //*************实现排行榜DVD开始************* public void listDVD(){ System.out.println("欢迎进入Dvd排行榜"); TreeSet set = new TreeSet<>(new DVDSetcompare()); for (int i = 0; i < list.size(); i++) { DVDSet dvdSet = (DVDSet)list.get(i); set.add(dvdSet); } Object[] arr = set.toArray(); int num = 0; for (int i = set.size()-1; i >=0; i--) { num++; System.out.println("第"+num+"名"+" "+arr[i]); } returnMain(); } } public class Demo { /** * @param args */ public static void main(String[] args) { DVDMgr dm = new DVDMgr(); dm.initial(); dm.startMenu(); } }