Question

JAVA实现面对对象编程，这道题怎么做？

开发NBA球队管理系统，可实现添加球队，查看球队，删除球员，导出球员，退出等功能。不使用数据库，使用对像和集合存储数据！！！

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Answer 1

Index.java

import java.io.BufferedWriter;
import java.io.FileWriter;
import java.io.IOException;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.Scanner;
import java.util.Set;

public class Index {
	// 创建全局键盘输入对象.
	static Scanner sc;

	public static void main(String[] args) throws IOException {
		sc = new Scanner(System.in);
		// 创建Map映射,键为球队编号,值为球队类.
		HashMap<String, Team> teams = new HashMap<String, Team>();
		// 循环命名,用于指定退出和继续.
		Loop: while (true) {
			// 打印选项
			System.out.println("1.添加球队 2.查看球队 3.删除球员信息 4.导出球队信息 5.退出");
			String option = sc.nextLine();
			switch (option) {
			case "1": 		// 1.添加球队
				addTeam(teams);
				break;
			case "2": 		// 2.查看球队
				viewTeam(teams);
				break;
			case "3":		// 3.删除球员
				deletePlayer(teams);
				break;
			case "4": 		// 4.导出信息
				exportInfo(teams);
				break;
			case "5": 		// 5.退出系统
				exit();
				sc.close(); // 退出此系统之前关闭输入流.
				break Loop;
			default: 		// 其他情况
				System.out.println("错误输入,请重新输入:");
				continue Loop;
			}
		}
	}

	// 根据球队编号添加队伍,添加队伍的同时在球队中添加球员对象.
	public static void addTeam(Map<String, Team> teams) {
		System.out.println("请输入球队编号:");
		String teamID = sc.nextLine();
		// 创建新球队对象.
		Team team = new Team();
		team.setTeamID(teamID);
		// 把创建的球队对象加入map映射中.
		teams.put(teamID, team);
		System.out.println("请输入球队名字:");
		String teamName = sc.nextLine();
		team.setTeamName(teamName);
		System.out.println("请输入球队所在城市:");
		String teamCity = sc.nextLine();
		team.setTeamCity(teamCity);
		// 新建一个布尔变量用于判断是否继续添加.
		boolean flag = true;
		while (flag) {
			System.out.println("请输入球员名字:");
			String playerName = sc.nextLine();
			System.out.println("请输入球员场均得分:");
			double pointsPerGame = sc.nextDouble();
			sc.nextLine();
			System.out.println("请选择球员类型: 1.前锋 2.中锋 3.后卫");
			// 新建一个position变量,判断添加的球员类型.
			int position = sc.nextInt();
			sc.nextLine();
			if (position == 1) {
				Forward player = new Forward();
				team.setPlayers(player);
				player.setPlayerPosition("前锋");
				System.out.println("请输入场均篮板:");
				double reboundsPerGame = sc.nextDouble();
				sc.nextLine();
				player.setPlayerName(playerName);
				player.setPointsPerGame(pointsPerGame);
				player.setReboundsPerGame(reboundsPerGame);
			} else if (position == 2) {
				Center player = new Center();
				team.setPlayers(player);
				player.setPlayerPosition("中锋");
				System.out.println("请输入场均盖帽:");
				double blocksPerGame = sc.nextDouble();
				sc.nextLine();
				player.setPlayerName(playerName);
				player.setPointsPerGame(pointsPerGame);
				player.setBlocksPerGame(blocksPerGame);
			} else {
				Guard player = new Guard();
				team.setPlayers(player);
				player.setPlayerPosition("后卫");
				System.out.println("请输入场均助攻:");
				double assistsPerGame = sc.nextDouble();
				sc.nextLine();
				player.setPlayerName(playerName);
				player.setPointsPerGame(pointsPerGame);
				player.setAssistsPerGame(assistsPerGame);
			}
			System.out.println("是否继续添加:(Y/N)");
			String isAdd = sc.nextLine();
			if (isAdd.equalsIgnoreCase("y"))
				flag = true;
			else
				flag = false;
		}
		System.out.println("球队编号\t球队名称\t球队所在城市");
		System.out.println(team.getTeamID() + "\t\t" + team.getTeamName() + "\t\t" + team.getTeamCity());
	}

	// 根据队伍,输出球员信息.
	public static void viewTeam(Map<String, Team> teams) {
		// 用keySet方法取出map映射中的键.用于迭代取Team对象.
		Set<String> keyset = teams.keySet();
		for (Iterator<String> itt = keyset.iterator(); itt.hasNext();) {
			String tmp = itt.next();
			Team team = teams.get(tmp);
			System.out.println("球队编号\t球队名称\t球队所在城市");
			System.out.println(team.getTeamID() + "\t\t" + team.getTeamName() + "\t\t" + team.getTeamCity());
			// 得到Team对象之后,迭代其中的ArrayList,其中存储了球员对象.
			System.out.println("球员名字\t场均得分\t球员类型");
			for (Iterator<Player> itp = team.getPlayers().iterator(); itp.hasNext();) {
				Player player = itp.next();
				if (player.getPlayerPosition().equals("前锋"))
					player = (Forward) player;
				else if (player.getPlayerPosition().equals("中锋"))
					player = (Center) player;
				else
					player = (Guard) player;
				System.out.println(player);
			}
		}
	}

	// 先根据球队编号,再删除球员,如没有球队/员则会提示.
	public static void deletePlayer(Map<String, Team> teams) {
		System.out.println("请输入要删除的球队编号");
		String teamID = sc.nextLine();
		// 判断map映射中是否存在输入的球队编号,无则跳回选择界面.
		if (teams.containsKey(teamID)) {
			Team team = teams.get(teamID);
			System.out.println("请输入球员姓名:");
			String playerName = sc.nextLine();
			boolean flag = false;
			for (Iterator<Player> it = team.getPlayers().iterator(); it.hasNext();) {
				Player tmp = it.next();
				if (playerName.equals(tmp.getPlayerName())) {
					flag = true;
					it.remove();
					System.out.println("删除成功");
					break;
				}
			}
			if (!flag)
				System.out.println("删除失败,无此球员");
		} else
			System.out.println("无此球队,请重新选择功能.");
	}

	// 导出球队信息到当前目录.

	public static void exportInfo(Map<String, Team> teams) throws IOException {
		Set<String> keyset = teams.keySet();
		// 通过判断keySet的长度判断是否输入过球队信息.
		if (keyset.size() != 0) {
			BufferedWriter bfw = new BufferedWriter(new FileWriter("Teams.txt"));
			for (Iterator<String> it = keyset.iterator(); it.hasNext();) {
				String tmp = it.next();
				Team team = teams.get(tmp);
				bfw.write("球队编号\t球队名称\t球队所在城市");
				bfw.newLine();
				bfw.write(team.getTeamID() + "\t\t" + team.getTeamName() + "\t\t" + team.getTeamCity());
				bfw.newLine();
			}
			bfw.close();
		} else {
			System.out.println("请先输入球队信息,再导出.");
		}
	}

	// 退出系统.
	public static void exit() {
		System.out.println("欢迎下次再来.");
	}
}

Team.java

import java.util.ArrayList;

public class Team {
	private String teamID;			// 球队编号
	private String teamName;		// 球队名字
	private String teamCity;		// 球队所在城市
	private ArrayList<Player> players;	// 球员集合

	public Team() { // 实例化Team的同时,实例化ArrayList集合.
		players = new ArrayList<>();
	}

	// 各属性get和set方法
	public String getTeamID() {
		return teamID;
	}

	public void setTeamID(String teamID) {
		this.teamID = teamID;
	}

	public String getTeamName() {
		return teamName;
	}

	public void setTeamName(String teamName) {
		this.teamName = teamName;
	}

	public String getTeamCity() {
		return teamCity;
	}

	public void setTeamCity(String teamCity) {
		this.teamCity = teamCity;
	}

	public ArrayList<Player> getPlayers() {
		return players;
	}

	// players的set方法,直接将球员添加到ArrayList中.
	public void setPlayers(Player player) {
		players.add(player);
	}

}

Player.java

public class Player {
	protected String playerName;		// 球员姓名
	protected double pointsPerGame;	// 场均得分
	protected String playerPosition;	// 球员类型

	// 各个属性的get,set方法
	public String getPlayerName() {
		return playerName;
	}

	public void setPlayerName(String playerName) {
		this.playerName = playerName;
	}

	public double getPointsPerGame() {
		return pointsPerGame;
	}

	public void setPointsPerGame(double pointsPerGame) {
		this.pointsPerGame = pointsPerGame;
	}

	public String getPlayerPosition() {
		return playerPosition;
	}

	public void setPlayerPosition(String playerPosition) {
		this.playerPosition = playerPosition;
	}

	// 重写toString方法,方便输出
	public String toString() {
		return playerName + "\t\t" + pointsPerGame + "\t\t" + playerPosition;
	}
}

Forward.java

public class Forward extends Player {
	private double reboundsPerGame; // 场均篮板

	// get,set方法
	public double getReboundsPerGame() {
		return reboundsPerGame;
	}

	public void setReboundsPerGame(double reboundsPerGame) {
		this.reboundsPerGame = reboundsPerGame;
	}

	// 重写toString方法,方便输出
	public String toString() {
		return playerName + "\t\t" + pointsPerGame + "\t\t" + playerPosition + "\t\t" + "场均篮板\t\t" + reboundsPerGame;
	}
}

Center.java

public class Center extends Player {
	private double blocksPerGame; // 场均盖帽

	// get,set方法
	public double getBlocksPerGame() {
		return blocksPerGame;
	}

	public void setBlocksPerGame(double blocksPerGame) {
		this.blocksPerGame = blocksPerGame;
	}

	// 重写toString方法,方便输出
	public String toString() {
		return playerName + "\t\t" + pointsPerGame + "\t\t" + playerPosition + "\t\t" + "场均盖帽\t\t" + blocksPerGame;
	}
}

Guard.java

public class Guard extends Player {
	private double assistsPerGame; // 场均助攻

	// get,set方法
	public double getAssistsPerGame() {
		return assistsPerGame;
	}

	public void setAssistsPerGame(double assistsPerGame) {
		this.assistsPerGame = assistsPerGame;
	}

	// 重写toString方法,方便输出
	public String toString() {
		return playerName + "\t\t" + pointsPerGame + "\t\t" + playerPosition + "\t\t" + "场均助攻\t\t" + assistsPerGame;
	}
}

除了注释外有不懂的追问,功能都测试过可以使用,求采纳.

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