Collection和Collections区别

collections是一个静态类，它包含有各种有关集合操作的静态多态方法。此类不能实例化，就像一个工具类，服务于Java的Collection框架。

接口Collection代码：

public interface Collection<E> extends Iterable<E> {
  int size();
 boolean isEmpty();
 boolean contains(Object o);
 Iterator<E> iterator();
 Object[] toArray();
 <T> T[] toArray(T[] a);
 boolean add(E e);
 boolean remove(Object o);
 boolean containsAll(Collection<?> c);
 boolean addAll(Collection<? extends E> c);
 boolean removeAll(Collection<?> c);
 boolean retainAll(Collection<?> c);
 void clear();
 boolean equals(Object o);
 int hashCode();

}

public class Collections {

}