获取错误：非静态方法getTotalPlayers（）不能从静态上下文中引用

Question

我没有看到我在这里做错了什么，或者这里的任何东西是静态的，没有以这种方式声明。我只需要在这里指出正确的方向。

测试代码：

public class PaintballPlayerTest 
{ 
//Test program for PaintballPlayer assignment 

public static void main (String [] args) 
{ 
//Part 1 check constructor & toString --(make sure ID is working too) 
PaintballPlayer sheldon = new PaintballPlayer ("Sheldon", "Lee", "Cooper"); 
PaintballPlayer leonard = new PaintballPlayer ("Leonard", "Hofstadter"); 
PaintballPlayer amy = new PaintballPlayer ("Amy", "Farrah", "Fowler"); 

System.out.println(sheldon); 
System.out.println(leonard); 

//Part 2 test getTotalPlayer --should be 3 
System.out.println("The team has this many players " + PaintballPlayer.getTotalPlayers()); 

我的代码：

import java.util.*; 

public class PaintballPlayer 
{ 
private String firstName, middleName, lastName; 
private String secFirst, secLast; 
private int id; 
private int count; 
private static int totalPlayers; 
private int playerID; 
private int players; 

public PaintballPlayer(String first, String middle, String last) 
{ 
    count = 0; 
    id = totalPlayers++; 
    players = count++; 
    firstName = first; 
    middleName = middle; 
    lastName = last; 
} 

public PaintballPlayer(String f, String l) 
{ 
    this (f,"",l); 
    id = count++; 


} 


public PaintballPlayer() 
{ 
totalPlayers++; 
} 

public static int getTotalPlayers() 
{ 
return totalPlayers; 
} 

public String toString() 
{ 
    String name; 
    String n; 
    name = firstName + " " + middleName + " " + lastName; 

    return name; 

} 


public int getPlayerID() 
{ 
    playerID = count; 
    return playerID; 
} 
    } 

同样，我的问题是与getTotalPlayers（）方法。

编辑：这是我编辑的代码应用所提供的修复程序。谢谢！

Answer 1

getTotalPlayers()不是一个静态方法，所以你需要一个PaintballPlayer的实例来调用这个方法。

如果你想总的玩家店内PaintballPlayer，你需要一个静态的属性（所有实例相同的参考）：

class PaintballPlayer { 

    private static int totalPlayers; 

    public PaintballPlayer() { 
    totalPlayers++; 
    } 

    public static int getTotalPlayers() { 
    return totalPlayers; 
    } 
} 

Answer 2

在你的代码有几个问题，在构造＃1

public PaintballPlayer(String first, String middle, String last) 
{ 
    count = 0; 
    players = 0; 
    id = count++; 
    players = count++; 
    firstName = first; 
    middleName = middle; 
    lastName = last; 
} 

变量玩家和计数正在重置，而变量计数增加了两倍。

并在构造＃2的问题是最糟糕的：

public PaintballPlayer(String f, String l) 
{ 
    this (f,"",l); 
    id = count++; 
    players = count++; 
} 

，因为你都在增加数量的，除了在原有的构造函数中的2次的两倍，因此在总值的四倍。

一旦u必须做的事情德文弗里兹说你将不得不修改PaintballPlayer

的构造

public PaintballPlayer(String first, String middle, String last) 
{ 
    id = totalPlayers++; 
    firstName = first; 
    middleName = middle; 
    lastName = last; 
} 

Answer 3

试试这个。

import java.util.*; 

public class PaintballPlayer { 

    private String firstName, middleName, lastName; 
    private String secFirst, secLast; 
    private int id; 
    private static int count; 
    private static int totalPlayers; 
    private int playerID; 
    private static int players; 

    public PaintballPlayer(String first, String middle, String last) { 
     count++; 
     id = count; 
     players = count; 
     firstName = first; 
     middleName = middle; 
     lastName = last; 
    } 

    public PaintballPlayer(String f, String l) { 
     this(f, "", l); 
     id = count; 
     players = count; 
    } 

    public String toString() { 
     String name = firstName + " " + middleName + " " + lastName; 
     return name; 
    } 

    public static int getTotalPlayers() { 
     totalPlayers = players; 
     return totalPlayers; 
    } 

    public int getPlayerID() { 
     playerID = count; 
     return playerID; 
    } 
} 

class PaintballPlayerTest { 
//Test program for PaintballPlayer assignment 

    public static void main(String[] args) { 
//Part 1 check constructor & toString --(make sure ID is working too) 
     PaintballPlayer sheldon = new PaintballPlayer("Sheldon", "Lee", "Cooper"); 
     PaintballPlayer leonard = new PaintballPlayer("Leonard", "Hofstadter"); 
     PaintballPlayer amy = new PaintballPlayer("Amy", "Farrah", "Fowler"); 

     System.out.println(sheldon); 
     System.out.println(leonard); 

//Part 2 test getTotalPlayer --should be 3 
     System.out.println("The team has this many players " + PaintballPlayer.getTotalPlayers()); 
    } 
}