Java对象不保存其属性值[重复]

Question

下午好。

我有一个 City 类，它接收到其他 City 对象的不同距离值。

但是，在我创建城市并添加距离后，每个城市都会获得相同的距离值，这是最后一个添加的城市的值。

也就是说，运行之后 cityA.toString 的输出应该是 {B=5, C=4, D=7, E=6, F=5, G=7, H=4, I=2, J=9} 而不是 {A=6, B=5, C=5, D=6, E=4, F=8, G=5, H=4, I=3, J=8}

你知道我做错了什么吗？谢谢

public class City {

private String name;
private static HashMap<String, Integer> distancias;

public City(String name){
    this.name = name;
    distancias = new HashMap<String, Integer>();
}

public void insertDistances(City city, int dist) {
    distancias.put(city.getName(), dist);
}


public static void main(String[] args) {

    City cityA = new City("A");
    City cityB = new City("B");
    City cityC = new City("C");
    City cityD = new City("D");
    City cityE = new City("E");
    City cityF = new City("F");
    City cityG = new City("G");
    City cityH = new City("H");
    City cityI = new City("I");
    City cityJ = new City("J");

    cityA.insertDistances(cityB, 5);
    cityA.insertDistances(cityC, 4);
    cityA.insertDistances(cityD, 7);
    cityA.insertDistances(cityE, 6);
    cityA.insertDistances(cityF, 5);
    cityA.insertDistances(cityG, 7);
    cityA.insertDistances(cityH, 4);
    cityA.insertDistances(cityI, 2);
    cityA.insertDistances(cityJ, 9);

    cityB.insertDistances(cityA, 6);
    cityB.insertDistances(cityC, 5);
    cityB.insertDistances(cityD, 6);
    cityB.insertDistances(cityE, 4);
    cityB.insertDistances(cityF, 8);
    cityB.insertDistances(cityG, 5);
    cityB.insertDistances(cityH, 4);
    cityB.insertDistances(cityI, 3);
    cityB.insertDistances(cityJ, 8);

}

}

Answer 1

private static HashMap<String, Integer> distancias;

去除静电 改用private HashMap<String, Integer> distancias`

静态变量对于类的所有实例（或对象）是通用的，因为它是类级别的变量。