原来Java中有两个ArrayList

public class AslistMethod {
 public static void main(String[] args) {
  String sentence = "i love you";
  List<String> words = Arrays.asList(sentence.split(" "));
  for (int i = 0; i < words.size(); ) {
   if (words.get(i).equals("love")) {
    words.remove(i);
    continue;
   }
   i++;
  }
  System.out.println(words);
 }

Exception in thread "main" java.lang.UnsupportedOperationException
 at java.util.AbstractList.remove(AbstractList.java:161)
 at list.AslistMethod.main(AslistMethod.java:12)

words.remove(i);

 private static class ArrayList<E> extends AbstractList<E>
  implements RandomAccess, java.io.Serializable
 {
  private static final long serialVersionUID = -2764017481108945198L;
  private final E[] a;

  ArrayList(E[] array) {
   a = Objects.requireNonNull(array);
  }

  @Override
  public int size() {
   return a.length;
  }

  @Override
  public Object[] toArray() {
   return a.clone();
  }

  @Override
  @SuppressWarnings("unchecked")
  public <T> T[] toArray(T[] a) {
   int size = size();
   if (a.length < size)
    return Arrays.copyOf(this.a, size,
          (Class<? extends T[]>) a.getClass());
   System.arraycopy(this.a, 0, a, 0, size);
   if (a.length > size)
    a[size] = null;
   return a;
  }

  @Override
  public E get(int index) {
   return a[index];
  }

  @Override
  public E set(int index, E element) {
   E oldValue = a[index];
   a[index] = element;
   return oldValue;
  }

  @Override
  public int indexOf(Object o) {
   if (o==null) {
    for (int i=0; i<a.length; i++)
     if (a[i]==null)
      return i;
   } else {
    for (int i=0; i<a.length; i++)
     if (o.equals(a[i]))
      return i;
   }
   return -1;
  }

  @Override
  public boolean contains(Object o) {
   return indexOf(o) != -1;
  }

  @Override
  public Spliterator<E> spliterator() {
   return Spliterators.spliterator(a, Spliterator.ORDERED);
  }
 }

 public E remove(int index) {
  throw new UnsupportedOperationException();
 }

at java.util.AbstractList.remove(AbstractList.java:161)