java.util.ConcurrentModificationException

java.util.ConcurrentModificationException

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class ListOfRemove {
    public static void main(String[] args) {
        List<Integer> list = new ArrayList(Arrays.asList(1, 2, 10, 20, 30));
        Iterator<Integer> it = list.iterator();
        while (it.hasNext()) {
            int x = it.next();
            if (x >= 10) {
                list.remove(Integer.valueOf(x));
            }
        }
        System.out.println("Modified ArrayList : " + list);
    }
}

应该使用 Iterator(迭代器) 的 remove() 方法删除

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;

public class ListOfRemove {
    public static void main(String[] args) {
        List<Integer> list = new ArrayList(Arrays.asList(1, 2, 10, 20, 30));
        Iterator<Integer> it = list.iterator();
        while (it.hasNext()) {
            int x = it.next();
            if (x >= 10) {
                it.remove();
            }
        }
        System.out.println("Modified ArrayList : " + list);
    }
}

Modified ArrayList : [1, 2]