為什么以下代碼不能生成正確的 output？

Question

您被要求使用 Java 代碼編寫一份關於美國國家橄欖球聯盟 (NFL) 傳球和接球統計的報告。 四分衛和外接手有一些共同的信息，但其他信息特定於他們的 position。

播放器 Class

public class Player {

    String firstName; 
    String lastName; 
    String team;
    String position;

    public Player(String firstName, String lastName, String team, String position) 
    {
        super();
        this.firstName = firstName;
        this.lastName = lastName;
        this.team = team;
        this.position = position;
    }

    public String getFirstName()
    {
        return firstName;
    }

    public void setFirstName(String firstName) 
    {
        this.firstName = firstName;
    }

    public String getLastName()
    {
        return lastName;
    }

    public void setLastName(String lastName)
    {
        this.lastName = lastName;
    }

    public String getTeam() 
    {
        return team;
    }

    public void setTeam(String team) 
    {
        this.team = team;
    }

    public String getPosition() 
    {
        return position;
    }

    public void setPosition(String position) 
    {
        this.position = position;
    }
} 

四分衛 Class

public class Quarterback extends Player {
    int completions; 
    int attempts;
    int yards;

    public Quarterback(String firstName, String lastName, String team,
            String position, int completions, int attempts, int yards) 
    {

        super(firstName, lastName, team, position);
        this.completions = completions;
        this.attempts = attempts;
        this.yards = yards;
    }

    public int getCompletions() 
    {
        return completions;
    }

    public void setCompletions(int completions) 
    {
        this.completions = completions;
    }

    public int getAttempts() 
    {
        return attempts;
    }

    public void setAttempts(int attempts)
    {
        this.attempts = attempts;
    }

    public int getYards() 
    {
        return yards;
    }

    public void setYards(int yards)
    {
        this.yards = yards;
    }

    public double percent() 
    {
        return ((double) completions / (double) attempts) * 100.0d;
    }

    public double yardsPerAttempt() 
    {
        return (double) yards / (double) attempts;
    }

    public double yardsPerGame() 
    {
        return (double) yards / (double) 16.0d;
    }
}

接收器 Class

public class Receiver extends Player{
    int receptions;
    int yards;
    public Receiver(String firstName, String lastName, String team,
            String position, int receptions, int yards) 
    {
        super(firstName, lastName, team, position);
        this.receptions = receptions;
        this.yards = yards;
    }

    public int getReceptions()
    {
        return receptions;
    }

    public void setReceptions(int receptions) 
    {
        this.receptions = receptions;
    }

    public int getYards()
    {
        return yards;
    }

    public void setYards(int yards)
    {
        this.yards = yards;
    }

    public double yardsPerReception() 
    {
        return (double) yards / (double) receptions;
    }

    public double yardsPerGame() 
    {
        return (double) yards / 16.0d;
    }
}

下面是我的問題，顯示 output 正在發生。

import java.io.File;
import java.util.Scanner;

public class NFLTestPlayer 
{

    public static void main(String[] args) 
    {
        Scanner scanner = null;

        try 
        {
            Player players[] = new Player[20];
            scanner = new Scanner(new File("nfl.txt"));
            int count = 0;


            while (scanner.hasNext())
            {
                String firstName, lastName, team, position;
                firstName = scanner.next();
                lastName = scanner.next();
                team = scanner.next();
                position = scanner.next();

                if (position.equals("QB")) 
                {
                    int completions, attempts, yards;
                    completions = scanner.nextInt();
                    attempts = scanner.nextInt();
                    yards = scanner.nextInt();

                    players[count++] = new Quarterback(firstName, lastName,
                            team, position, completions, attempts, yards);
                    } 
                else if (position.equals("WR")) 
                {
                    int receptions;
                    int yards;
                    receptions = scanner.nextInt();
                    yards = scanner.nextInt();
                    players[count++] = new Receiver(firstName, lastName, team,
                            position, receptions, yards);
                    }
                }
            System.out.println("NFL 2018 Player Passing/Receiving Statistics\n");
            System.out.println("Quarterbacks");

            System.out.printf("%-25s %-5s %12s %12s %12s %12s %12s %12s\n",
                    "Player","Team", "Comp","Att","Pct","Yds","Yds/A","Yds/G");

            for (int i = 0; i < players.length; i++)
            {
                if (players[i] instanceof Quarterback) 
                {
                    Quarterback quarterback = (Quarterback) players[i];
                    System.out.printf("%-25s %-5s %12.0f %12.0f %12.0f %12.1f %12.2f %12d",
                            quarterback.getFirstName() 
                            + ","  + quarterback.getLastName() 
                            + quarterback.getTeam()
                            + quarterback.getCompletions()
                            + quarterback.getAttempts()

                            + quarterback.getYards()
                            +quarterback.yardsPerAttempt() 
                            +quarterback.yardsPerGame());
                    }
                }

            System.out.println("\n");
            System.out.println("Wide Receivers");
            System.out.printf("%-25s %-5s %12s %12s %12s %12s\n",
                    "Player","Team", "Rec", "Yds","Yds/R","Yds/G");


            for (int i = 0; i < players.length; i++) 
            {
                if (players[i] instanceof Receiver)
                {
                    Receiver receiver = (Receiver) players[i];
                    System.out.printf("%-25s %-5s %12.0f %12.0f %12.0f %12.1f",
                            receiver.getFirstName()
                            + ","  + receiver.getLastName()
                            + receiver.getTeam()
                            + receiver.getReceptions()
                            + receiver.getYards()
                            + receiver.yardsPerReception()
                            + receiver.yardsPerGame());
                    }
                }
            } catch (Exception e)
        {
                e.printStackTrace();        
        }
    }
}

output 應使用以下文本文件創建表：

NFL.txt

Ben Roethlisberger PIT QB 452 675 5129
Julio Jones ATL WR 113 1677 
Aaron Rodgers GB QB 372 597 4442
Patrick Mahomes KC QB 383 580 5097
JuJuj Smith-Schuster PIT WR 111 1426 
Philip Rivers LAC QB 347 508 4308
DeAndre Hopkins HOU WR 115 1572 
Mike Evans TB WR 86 1524 
Matt Ryan ATL QB 422 608 4924
Davante Adams GB WR 111 1386 
Tyreek Hill KC WR 87 1479 
Michael Thomas NO WR 125 1405 
Jared Goff LAR QB 364 561 4688
Andrew Luck IND QB 430 639 4593
Adam Thielen MIN WR 113 1373 
Eli Manning NYG QB 380 576 4299
Kirk Cousins MIN QB 425 606 4298
Robert Woods LAR WR 86 1219 
Tom Brady NE QB 375 570 4355
Brandin Cooks LAR WR 80 1204


NFL 2018 Player Passing/Receiving Statistics            
Quarterbacks                            
Player         Team Comp Att Pct    Yds    Yds/A  Yds/6
Brady,Tom       NE  375 570  66.    4,355   8.     272
Cousins,Kirk    MIN 425 606  70.    4,298   7.     268
Goff,jared      LAR 364 561  65.    4,688   8.     293
Luck,Andrew     IND 430 639  67.    4,593   7.     287
Mahomes,Patrick KC  383 580  66.0   5,097   9.     318
Manning,Eli     NYG 380 576  66.0   4,299   7.     268
Rivers,Philip   LAC 347 508  68.    4,308   8.     269
Rodgers,Aaron   GB  372 597  62.    4,442   7.     277
Roethlisberger, PIT 452  675 67.0   5,129   7.60    320
Ryan,Matt       ATL 422 608  69.    4,924   8.10    307

Receivers                           
Player              Team    Rec  Yds   Yds/R    Yds/6       
Adams,Davante        G8     111 1,386   13.      87.        
Cooks,Brandin       LAR     80  1,204   15.      75.        
Evans,Mike           TB     86  1,524   18.      95.        
Hill,Tyreek          KC     87  1,479   17.0    92.     
Hopkins,DeAndre      HOU    115 1,572   14.     98.     
lonesOullo           ATL    113 1,677   15.     105.        
Smith-Schuster,JuJu PIT     111 1,426   13.     89.     
Thielen,Adam        KIN     113 1,373   12.     86.     
Thomas,Michael      NO      125 1,405   11.     88.     
Woods,Robert        LAR     86  1,219   14.     76.     

Answer 1

您能否更清楚一點並解釋您面臨的問題？ 你有什么錯誤嗎？ 還是output不一樣？

我四處走動，想知道您是否有java.util.MissingFormatArgumentException異常？

編輯：

好的，這是有原因的-您的格式不正確。 這是另一個問題的重復： java.util.MissingFormatArgumentException: Format specifier: s

System.out.printf("%-25s %-5s %12.0f %12.0f %12.0f %12.1f %12.2f",
                        quarterback.getFirstName() + " " + quarterback.getLastName(), quarterback.getTeam(), (double)quarterback.getCompletions(), (double)quarterback.getAttempts(), (double)quarterback.getYards(), quarterback.yardsPerAttempt(), quarterback.yardsPerGame());
System.out.println("/n");

但是，我強烈建議您閱讀有關使用說明符進行格式化的內容。 您收到該異常的原因是您沒有將變量正確地關聯到您的說明符。