java util, Collection Interface 除映射类型的集合外,接口java.uti. Collection是 所有集合类型的超类型,声明了与集合操作相关 的通用方法 public int sized public boolean isEmptyo public boolean contains(object elem) public Objectl toArrayo public Objectl toArray(objectl dest)java.util.Collection Interface • 除映射类型的集合外，接口java.util.Collection是 所有集合类型的超类型，声明了与集合操作相关 的通用方法 public int size() public boolean isEmpty() public boolean contains(Object elem) public Object[] toArray() public Object[] toArray(Object[] dest)