在使用阿里的代码规范检测插件后，不得不承认代码的质量提高了很多，在这里也推荐给大家：
这里遇到一个问题，在我写迭代器的时候通常是这么写的：
List <Integer> list = new ArrayList <>();
list.addAll(Arrays.asList(1, 2, 3, 4, 5));
final Iterator <Integer> iterator = list.iterator();
while (iterator.hasNext()){
final Integer i = iterator.next();
if(2 == i){
it.remove();
}
}但是阿里的插件检测出代码不规范，它的推荐写法是：
list.removeIf(i -> 2 == i);确实清爽了许多，简洁了许多，最关键的是很有效。
后来看了下源码：
/**
* Removes all of the elements of this collection that satisfy the given
* predicate. Errors or runtime exceptions thrown during iteration or by
* the predicate are relayed to the caller.
*
* @implSpec
* The default implementation traverses all elements of the collection using
* its {@link #iterator}. Each matching element is removed using
* {@link Iterator#remove()}. If the collection's iterator does not
* support removal then an {@code UnsupportedOperationException} will be
* thrown on the first matching element.
*
* @param filter a predicate which returns {@code true} for elements to be
* removed
* @return {@code true} if any elements were removed
* @throws NullPointerException if the specified filter is null
* @throws UnsupportedOperationException if elements cannot be removed
* from this collection. Implementations may throw this exception if a
* matching element cannot be removed or if, in general, removal is not
* supported.
* @since 1.8
*/
default boolean removeIf(Predicate<? super E> filter) {
Objects.requireNonNull(filter);
boolean removed = false;
final Iterator<E> each = iterator();
while (each.hasNext()) {
if (filter.test(each.next())) {
each.remove();
removed = true;
}
}
return removed;
}借用某人的翻译：
/**
* 移除集合中满足给定条件的所有元素，错误或者运行时异常发生在迭代时或者把条件传递给调用者的时候。
*
* @implSpec
* 默认的实现贯穿了使用迭代器iterator的集合的所有元素。每一个匹配的元素都将被用Iterator接口中的
* remove()方法移除。如果集合的迭代器不支持移除，则在第一次匹配时就会抛出异常 UnsupportedOperationException
*
* @param filter 令元素移除成功的条件
* @return {@code true} 如果所有的元素都被移除
* @throws NullPointerException 如果有一个过滤器是空的
* @throws UnsupportedOperationException 如果元素不能被从该集合中移除。如果一个匹配元素不能被移除，
* 通常来说，它就不支持移除操作，这时可能抛出这个异常。
* @since 1.8
*/
default boolean removeIf(Predicate<? super E> filter) {
Objects.requireNonNull(filter);
boolean removed = false;
final Iterator<E> each = iterator();
while (each.hasNext()) {
if (filter.test(each.next())) {
each.remove();
removed = true;
}
}
return removed;
}所以，以后还是用新方法吧，与时俱进哦。
