Generics Challenge - 기본예제에 league 추가

(하단에 문제)

 

Player(abstract class)  - Team(generics class) - league(generics class) - main

player (sub class)         (team 여러개)           (league여러개)

player                                 -generics로 간단하게

 

나머지 class 코딩은 기본예제와 동일 (Player, Team)

 

League class - generics extends Team.

package com.timbuchalka;

import java.util.ArrayList;
import java.util.Collections;

/**
 * Created by dev on 18/10/2015.
 */
public class League<T extends Team> {
    public String name;
    private ArrayList<T> league = new ArrayList<>();

    public League(String name) {
        this.name = name;
    }

    public boolean add(T team) {
        if(league.contains(team)) {
            return false;
        }
        league.add(team);
        return true;
   }

    public void showLeagueTable() {
        Collections.sort(league);			//collection.sort : arrayList값들 정렬
        for(T t : league) {						// 알파벳순, 혹은 숫자순으로 자동으로 저장.
            System.out.println(t.getName() + ": " + t.ranking());
        }
    }
}

Main

package com.timbuchalka;

public class Main {

    public static void main(String[] args) {
	   
        League<Team<FootballPlayer>> footballLeague = new League<>("AFL");
        Team<FootballPlayer> adelaideCrows = new Team<>("Adelaide Crows");
        Team<FootballPlayer> melbourne = new Team<>("Melbourne");
        Team<FootballPlayer> hawthorn= new Team<>("Hawthorn");
        Team<FootballPlayer> fremantle= new Team<>("Fremantle");
        Team<BaseballPlayer> baseballTeam = new Team<>("Chicago Cubs");

        hawthorn.matchResult(fremantle, 1, 0);
        hawthorn.matchResult(adelaideCrows, 3, 8);

        adelaideCrows.matchResult(fremantle, 2, 1);

        footballLeague.add(adelaideCrows);
        footballLeague.add(melbourne);
        footballLeague.add(hawthorn);
        footballLeague.add(fremantle);

//        footballLeague.add(baseballTeam);
        footballLeague.showLeagueTable();


        // 아래처럼 League<Team<T>>, Team<T> 값처럼 generics 안쓰면 unchecked오류 안뜬다.코딩때

        BaseballPlayer pat = new BaseballPlayer("Pat");
        SoccerPlayer beckham = new SoccerPlayer("Beckham");
        Team rawTeam = new Team("Raw Team");
        rawTeam.addPlayer(beckham); // unchecked warning
        rawTeam.addPlayer(pat);     // unchecked warning

        footballLeague.add(rawTeam);     // unchecked warning

        League<Team> rawLeague = new League<>("Raw");
        rawLeague.add(adelaideCrows);     // no warning
        rawLeague.add(baseballTeam);    // no warning
        rawLeague.add(rawTeam);         // no warning

        League reallyRaw = new League("Really raw");
        reallyRaw.add(adelaideCrows);     // unchecked warning
        reallyRaw.add(baseballTeam);    // unchecked warning
        reallyRaw.add(rawTeam);         // unchecked warning


    }
}

Output

D:\IT\JDK\jdk11.0.6_10\bin\java.exe "-javaagent:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\lib\idea_rt.jar=51059:D:\IT\IDEA\IntelliJ IDEA Community Edition 2020.1\bin" -Dfile.encoding=UTF-8 -classpath D:\IT\Java-Generics-Generics-Challenge-Source-code\out\production\GenericsChallenge com.timbuchalka.Main
Hawthorn beat Fremantle
Hawthorn lost to Adelaide Crows
Adelaide Crows beat Fremantle
Adelaide Crows: 4
Hawthorn: 2
Melbourne: 0
Fremantle: 0
Beckham picked for team Raw Team
Pat picked for team Raw Team

Process finished with exit code 0

 

나머지 class들 참고 /나머지 클래스들 기본예제와 동일.

 

Player class  (abstract class)

package com.timbuchalka;

/**
 * Created by dev on 17/10/2015.
 */
public abstract class Player {
    private String name;

    public Player(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }
}

sub class 2개 - player

package com.timbuchalka;					//subClass 1

/**
 * Created by dev on 17/10/2015.
 */
public class BaseballPlayer extends Player {
    public BaseballPlayer(String name) {
        super(name);
    }
}

											//subClass 2
package com.timbuchalka;

/**
 * Created by dev on 17/10/2015.
 */
public class SoccerPlayer extends Player {

    public SoccerPlayer(String name) {
        super(name);
    }
}

Team class (generics)

package com.timbuchalka;

import java.util.ArrayList;

/**
 * Created by dev on 17/10/2015.
 */
public class Team<T extends Player> implements Comparable<Team<T>> {
    private String name;
    int played = 0;
    int won = 0;
    int lost = 0;
    int tied = 0;


    private ArrayList<T> members = new ArrayList<>();

    public Team(String name) {
        this.name = name;
    }

    public String getName() {
        return name;
    }

    public boolean addPlayer(T player) {
        if (members.contains(player)) {
            System.out.println(player.getName() + " is already on this team");
            return false;
        } else {
            members.add(player);
            System.out.println(player.getName() + " picked for team " + this.name);
            return true;
        }
    }

    public int numPlayers() {
        return this.members.size();
    }

    public void matchResult(Team<T> opponent, int ourScore, int theirScore) {

        String message;

        if(ourScore > theirScore) {
            won++;
            message = " beat ";
        } else if(ourScore == theirScore) {
            tied++;
            message = " drew with ";

        } else {
            lost++;
            message = " lost to ";
        }
        played++;
        if(opponent != null) {
            System.out.println(this.getName() + message + opponent.getName());
            opponent.matchResult(null, theirScore, ourScore);
        }
    }

    public int ranking() {
        return (won * 2) + tied;
    }

    @Override
    public int compareTo(Team<T> team) {
        if(this.ranking() > team.ranking()) {
            return -1;
        } else if(this.ranking() < team.ranking()) {
            return 1;
        } else {
            return 0;
        }
    }
}

 

문제.

// ArrayList<Team> teams;
// Collections.sort(teams);
// Create a generic class to implement a league table for a sport.
// The class should allow teams to be added to the list, and store
// a list of teams that belong to the league.
//
// Your class should have a method to print out the teams in order,
// with the team at the top of the league printed first.
//
// Only teams of the same type should be added to any particular
// instance of the league class - the program should fail to compile
// if an attempt is made to add an incompatible team.