关于super()的孩子课有问题

时间:2010-12-06 00:16:49

标签: java inheritance

这是我的孩子班:

public class User extends Alien
{

protected XYCoordination currentLocation;
protected int energyCanister;
protected int lifePoints;

public User (XYCoordination currentLocation, int energyCanister, int lifePoints)
{
    super(currentLocation);
}
public int collectCanister()
{
    super.collectCanister();
    return energyCanister;
}
public int caculateLifePoints(int lifePoints)
{
    super.caculateLifePoints(lifePoints);
    return lifePoints;
}
}

这是我的父类:

public class Alien
{
protected XYCoordination currentLocation;
protected Planet currentPlanet;
protected int energyCanister;
protected int lifePoints;
protected int n;

public Alien(XYCoordination currentLocation, int energyCanister, int lifePoints)
{
    this.currentLocation = currentLocation;
    this.energyCanister = energyCanister;
    this.lifePoints = lifePoints;
}

public XYCoordination moveRight(XYCoordination toRight)
{
    currentLocation = currentLocation.addXToRight(toRight);
    return currentLocation;
}
public XYCoordination moveUp(XYCoordination toUp)
{
    currentLocation = currentLocation.addYToUp(toUp);
    return currentLocation;
}
public XYCoordination moveLeft(XYCoordination toLeft)
{
    currentLocation = currentLocation.addXToLeft(toLeft);
    return currentLocation;
}
public XYCoordination moveDown(XYCoordination toDown)
{
    currentLocation = currentLocation.addYToDown(toDown);
    return currentLocation;
}
public int collectCanister()
{
    energyCanister = energyCanister + (int)(n*currentPlanet.getRemainingCanister());
    return energyCanister;
}
public int caculateLifePoints(int lifePoints)
{
    lifePoints = (int)((2/3)*lifePoints);
    return lifePoints;
}
public void displayInfo()
{
    System.out.print("Currently you are in:" + currentLocation + "\t Currently you have" + energyCanister + "canisters" + "\tCurrently you have" + lifePoints + "lifepoints");
}
}

总是说“找不到'超级''。”

2 个答案:

答案 0 :(得分:4)

你的超类需要有一个与你正在调用的签名相匹配的构造函数。你有

public User (XYCoordination currentLocation, ....) {
    super(currentLocation);
}

您正在扩展的Alien类需要具有匹配签名的构造函数 -

public Alien(YCoordination currentLocation)

答案 1 :(得分:0)

当你说
时 超级(currentLocation); 使用单个参数currentLocation调用超类(父类)构造函数。但是你的超类Alien没有一个接受单个参数currentLocation的构造函数。

此上下文中的

Cannot find symbol super表示:您正在尝试使用单个参数调用超类构造函数,但我无法在超类中使用单个currentLocation参数找到构造函数。 / p>

您可能想要致电super(currentLocation, energyCanister, lifePoints)