【源码 JDK 1.8】List的源码解读

List依赖

List的依赖关系简单版，没有表明实现，因为目前只关注List的方法和源码，List的不同实现有 再做不同的解析

List源码

/**
 * An ordered collection (also known as a <i>sequence</i>).  
 * 一个有序的集合
 * The user of this interface has precise control over where in the list each element is inserted.  
 * 该这个接口可以精确控制每个元素在列表中的插入位置
 * 
 * The user can access elements by their integer index (position in the list), and search for elements in the list.
 * 用户可以通过索引位置获取list中的元素
 * 
 * Unlike sets, lists typically allow duplicate elements.  
 * 与sets不同，lists可以放入重复的元素
 * More formally, lists typically allow pairs of elements 
 * 更正式地说，列表通常允许成对的元素
 * e1 and e2 such that e1.equals(e2), 
 * and they typically allow multiple null elements if they allow null elements at all.  
 * 并且它们通常允许多个null元素，如果它们允许null元素
 * 
 * It is not inconceivable that someone might wish to implement a list that prohibits duplicates, by
 * throwing runtime exceptions when the user attempts to insert them, but we expect this usage to be rare.
 *
 * The List interface places additional stipulations, beyond those
 * specified in the Collection interface, on the contracts of the
 * iterator, add, remove, equals, and
 * hashCode methods.  
 * List接口在Collection接口规定的基础上，对iterator、add、remove、equals和hashCode方法添加了额外的实现
 * 
 * Declarations for other inherited methods are also included here for convenience.
 * 为了方便起见，这里还包含了其他继承方法的声明。
 * 
 * The List interface provides four methods for positional (indexed) access to list elements.  
 * List 提供了四种通过index进行元素访问的方法
 * 
 * Lists (like Java arrays) are zero based. 
 * List是从0开始索引
 * 
 * Note
 * that these operations may execute in time proportional to the index value
 * for some implementations (the LinkedList class, for example). 
 * 这些操作可能执行的时间与索引值成正比：这意味着对于某些实现（例如LinkedList类），访问列表中特定位置的元素（通过索引）的时间可能随着索引值的增加而增加。
 * 这是因为某些数据结构（如链表）访问中间元素可能需要更多的时间，而数组或某些其他数据结构则可以在恒定时间内访问任意元素
 * 
 * Thus, iterating over the elements in a list is typically preferable to indexing through it if the caller does not know the implementation.
 * 因此，通常更喜欢遍历列表元素而不是通过索引访问：这是基于上述性能考虑的建议。
 * 如果调用者不知道列表的具体实现类型，遍历列表元素通常是一个更好的选择，因为它避免了与索引值相关的性能问题。
 *
 * The List interface provides a special iterator, called a ListIterator, 
 * that allows element insertion and replacement, and bidirectional access in addition to the normal operations that the
 * Iterator interface provides.  A method is provided to obtain a
 * list iterator that starts at a specified position in the list.
 * List接口提供的特殊迭代器，称为ListIterator。与标准的Iterator接口相比，ListIterator允许在列表中插入和替换元素，并提供双向访问。
 * 这意味着你可以从列表的前面和后面遍历元素。此外，还提供了一个方法来获取从列表中特定位置开始迭代的ListIterator
 *
 * The List interface provides two methods to search for a specified object.  
 * From a performance standpoint, these methods should be used with caution. 
 * In many implementations they will perform costly linear searches.
 * 尽管List接口提供了搜索方法，但在某些实现中，这些方法可能会导致较低的性能，因为它们采用线性搜索方式。在处理大量数据时，使用其他更高效的搜索算法或数据结构可能更为合适。
 *
 * The List interface provides two methods to efficiently insert and
 * remove multiple elements at an arbitrary point in the list.
 * List接口提供了两种方法来有效地插入和删除列表中任意点的多个元素
 *
 * Note: While it is permissible for lists to contain themselves as elements,
 * extreme caution is advised: the equals and hashCode
 * methods are no longer well defined on such a list.
 * 虽然允许列表将其自身作为元素包含，但应极其谨慎行事。对于这样一个列表，equals和hashCode方法不再有明确定义
 *
 * Some list implementations have restrictions on the elements that they may contain. 
 * 一些列表实现对它们可能包含的元素有限制。
 * 
 * For example, some implementations prohibit null elements, and some have restrictions on the types of their elements.
 * 例如，有些实现禁止null元素，有些实现对其元素的类型有限制。
 * 
 * Attempting to add an ineligible element throws an unchecked exception, typically
 * NullPointerException or ClassCastException.  
 * 尝试添加不合格的元素会抛出一个未检查的异常，通常是NullPointerException或ClassCastException
 * 
 * Attempting to query the presence of an ineligible element may throw an exception, or it may simply return false; 
 * 尝试查询不合格元素的存在的行为可能会抛出异常，或者简单地返回false；
 * 
 * some implementations will exhibit the former behavior and some will exhibit the latter.  
 * 某些实现会表现出前一种行为，而其他实现则表现出后一种行为
 * 
 * More generally, attempting an operation on an ineligible element whose completion would not result in
 * the insertion of an ineligible element into the list may throw an
 * exception or it may succeed, at the option of the implementation.
 * 更一般地说，对不合格元素的尝试操作，如果其完成不会导致不合格元素被插入到列表中，可能会抛出异常，也可能会成功，这取决于实现的选择。
 * 
 * Such exceptions are marked as "optional" in the specification for this interface.
 * 此类异常在接口规范中被标记为“可选”。
 *

 *
 * @param <E> the type of elements in this list
 *
 * @author  Josh Bloch
 * @author  Neal Gafter
 * @see Collection
 * @see Set
 * @see ArrayList
 * @see LinkedList
 * @see Vector
 * @see Arrays#asList(Object[])
 * @see Collections#nCopi