Question

这是我的战士班。我想在这堂课上有一系列的战士。我们的想法是能够调用这样的方法 - ＆gt; warrior.select（1）它将获得在索引1处创建的战士。希望这是有道理的。请向我解释为什么会发生这种错误。

Exception in thread "main" java.lang.StackOverflowError
    at pking.Warrior.<init>(Warrior.java:42)

代码

package pking;

public class Warrior {

    private String name;
    private int age;
    private String call;
    private int attackPower;
    private String weapon;

    public Warrior(String myName, int myAge, String myCall, int myAttackPower) {
        name = myName;
        age = myAge;
        call = myCall;
        attackPower = myAttackPower;
        weapon = "";
        Warrior[] warriors = new Warrior[4];
        warriors[0] = new Warrior("Spartacus", 40, "I AM SPARTACUS!", 9000);
        warriors[1] = new Warrior("Crixus", 35, "CHAMPION OF CAPUA", 8000);
        warriors[2] = new Warrior("Gannicus", 30, "SLAYER", 8000);
        warriors[3] = new Warrior("Alexander", 21, "I AM ALEXANDER, THE CODER", 0);
    }

    //Prints warriors name
    public void name() {
        System.out.println(name);
    }

    //Prints warriors age
    public void age() {
        System.out.println(age);
    }

    //Prints warriors call
    public void warriorsCall() {
        System.out.println(call);
    }

    //Prints warriors attack power
    public void attackPower() {
        System.out.println(attackPower);
    }

    //Equips warriors weapon and prints message
    public void equip(String myWeapon) {
        weapon = myWeapon;
        System.out.println("Equiped the: " + weapon);
    }

    //Prints warriors weapon
    public void weapon() {
        System.out.println(weapon);
    }

}

Answer 1

您正在以递归方式调用它时，构造函数正在运行无限循环。在构造函数中检查以下行：

    Warrior[] warriors = new Warrior[4];
    warriors[0] = new Warrior("Spartacus", 40, "I AM SPARTACUS!", 9000);
    warriors[1] = new Warrior("Crixus", 35, "CHAMPION OF CAPUA", 8000);
    warriors[2] = new Warrior("Gannicus", 30, "SLAYER OF VAGINAS", 8000);
    warriors[3] = new Warrior("Alexander", 21, "I AM ALEXANDER, THE CODER", 0);

对于每个Warrior数组项实例化，你调用相同的构造函数，它再次尝试创建数组并初始化项，这一直持续到堆栈溢出。

更好的设计策略是创建一个新类，比如Legion，它将包含Warrior s的集合：

public class Legion {
    Warrior[] warriors;

    public Legion() {
        warriors = new Warrior[4];
        warriors[0] = new Warrior("Spartacus", 40, "I AM SPARTACUS!", 9000);
        warriors[1] = new Warrior("Crixus", 35, "CHAMPION OF CAPUA", 8000);
        warriors[2] = new Warrior("Gannicus", 30, "SLAYER OF VAGINAS", 8000);
        warriors[3] = new Warrior("Alexander", 21, "I AM ALEXANDER, THE CODER", 0);
    }

    // getters and setters
}

Answer 2

我不打算重复StackOverflow异常的原因，因为已经回答了（构造函数中的递归问题）。

但是，我认为您可能想要的是创建那些一次的4个特殊战士而不是Warrior的每个实例。也许你想以某种方式将它们作为常量。

所以也许是这样的：

public class Warrior {

    private static final List<Warrior> MEGA_WARRIORS =
        Collections.unmodifiableList(Arrays.asList(
            new Warrior("Spartacus", 40, "I AM SPARTACUS!", 9000),
            new Warrior("Crixus", 35, "CHAMPION OF CAPUA", 8000),
            new Warrior("Gannicus", 30, "SLAYER OF *censored*", 8000),
            new Warrior("Alexander", 21, "I AM ALEXANDER, THE CODER", 0)
        ));

    public static List<Warrior> getMegaWarriors() {
        return MEGA_WARRIORS;
    }

    private String name;
    private int age;
    private String call;
    private int attackPower;
    private String weapon;

    public Warrior(String myName, int myAge, String myCall, int myAttackPower) {
        name = myName;
        age = myAge;
        call = myCall;
        attackPower = myAttackPower;
        weapon = "";
    }

    //Prints warriors name
    public void name() {
        System.out.println(name);
    }

    //Prints warriors age
    public void age() {
        System.out.println(age);
    }

    //Prints warriors call
    public void warriorsCall() {
        System.out.println(call);
    }

    //Prints warriors attack power
    public void attackPower() {
        System.out.println(attackPower);
    }

    //Equips warriors weapon and prints message
    public void equip(String myWeapon) {
        weapon = myWeapon;
        System.out.println("Equiped the: " + weapon);
    }

    //Prints warriors weapon
    public void weapon() {
        System.out.println(weapon);
    }

}

为什么我在数组中的索引0上遇到堆栈溢出错误

2 个答案: