java - 从 TreeSet 中删除一个对象

Question

所以我有以下相关代码:

public static TreeSet<Object> set;



public static void remove(Object object){
    for (Object o : set){
        if (o.equals(object)){
            System.out.println("removing " + o);
            set.remove(o);
        }
    }
}

我向那个 TreeSet 添加了一些对象，然后我用某个 object1 作为参数调用 remove。 object1 在集合中，如

removingobject1

打印出来。

然而，当我之后使用这样的 for 循环打印出整个集合时:

for (Object o: set){
        System.out.println(o);
    }

它仍然打印出包括 object1 在内的整个集合。它显然在之前的集合中，Java 能够识别它，但是调用 set.remove(o) 绝对没有结果。

编辑:我试图让问题尽可能笼统，但这里是我正在使用的对象:

public class Player implements Comparable<Player>{

public String firstname;
public String lastname;
public int value;
public Position position;



public Player(String firstname, String lastname, int value, Position position){
this.firstname = firstname;
this.lastname = lastname;
this.value = value;
this.position = position;

}

public String toString(){
    return(firstname + " " + lastname")
}


public int compareTo(Player player){
    if (this.value > player.value){
        return -1;
    } else {
        return 1;
    }
}

Answer 1

您的删除方法可能如下所示:

public static void remove(Object object){
   set.remove(o);
}

方法 remove 删除集合中存在的元素，如果删除则返回 true。您不应在迭代期间修改您的集合 ( docs ):

The iterators returned by this class's iterator method are fail-fast: if the set is modified at any time after the iterator is created, in any way except through the iterator's own remove method, the iterator will throw a ConcurrentModificationException. Thus, in the face of concurrent modification, the iterator fails quickly and cleanly, rather than risking arbitrary, non-deterministic behavior at an undetermined time in the future.