【JAVA】四 JAVA集合 Collection ArrayList LinkedList

深碍√TFBOYSˉ_ 2022-07-24 11:25 208阅读 0赞

# **【JAVA】四 JAVA集合 Collection ArrayList LinkedList** #

# **Collection** #

Collection 已知子集

BeanContext, BeanContextServices, BlockingDeque<E>, BlockingQueue<E>, Deque<E>, 
    List<E>,NavigableSet<E>, Queue<E>, Set<E>, SortedSet<E>, TransferQueue<E>

![这里写图片描述][20160523235117428]

## **List** ##

### **ArrayList** ###

是实现了基于动态数组的数据结构 .  
ArrayList的内部实现是基于基础的对象数组 . 通过源码可以看到是Object\[\] 数组  
ArrayList实现java.util.RandomAccess 接口 .  
对于随机访问get和set，ArrayList觉得优于LinkedList, 因为LinkedList要移动指针。

#### **ArrayList私有属性** ####

public class ArrayList<E> extends AbstractList<E>
            implements List<E>, RandomAccess, Cloneable, java.io.Serializable
    {
        
        private static final long serialVersionUID = 8683452581122892189L;
    
        /** 
         *默认容量
         */
        private static final int DEFAULT_CAPACITY = 10;
    
        /**
         * 共享空数组实例用于空实例.
         */
        private static final Object[] EMPTY_ELEMENTDATA = {};
    
        /**
         * ArrayList的元素的数组缓冲区存储。
         * ArrayList的容量是这个数组的长度缓冲区。任何
         * 空ArrayList elementData = = EMPTY_ELEMENTDATA将扩大到
         * DEFAULT_CAPACITY当第一个元素被添加。
         */
        private transient Object[] elementData;
    
        /**
         * ArrayList的大小(它所包含的元素数量).
         *
         * @serial
         */
        private int size;
    }

#### **ArrayList构造方法** ####

/**
         * 构造一个与指定初始容量的空列表。
         * @param initialCapacity列表的初始容量如果指定初始容量
         * @throws IllegalArgumentException 负容量异常
         */
        public ArrayList(int initialCapacity) {
            super();
            if (initialCapacity < 0)
                throw new IllegalArgumentException("Illegal Capacity: "+
                                                   initialCapacity);
            this.elementData = new Object[initialCapacity];
        }
    
        /**
         * 构造一个空列表的初始容量10.
         */
        public ArrayList() {
            super();
            this.elementData = EMPTY_ELEMENTDATA;
        }
    
        /**
         * 构造一个包含指定的元素列表收集,它们的顺序返回的集合迭代器。
         * @param c元素的集合被放置到这个列表中如果指定集合为空
         * @throws NullPointerException
         */
        public ArrayList(Collection<? extends E> c) {
            elementData = c.toArray();
            size = elementData.length;
            // c.toArray might (incorrectly) not return Object[] (see 6260652)
            if (elementData.getClass() != Object[].class)
                elementData = Arrays.copyOf(elementData, size, Object[].class);
        }

<table> 
 <thead> 
  <tr> 
   <th>构造方法</th> 
   <th align="left"></th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>ArrayList()</td> 
   <td align="left">指定EMPTY_ELEMENTDATA,也就是一个空的ArrayList</td> 
  </tr> 
  <tr> 
   <td>ArrayList(int initialCapacity)</td> 
   <td align="left">指定ArrayList 的初始化大小</td> 
  </tr> 
  <tr> 
   <td>ArrayList(Collection c)</td> 
   <td align="left">接受一个Collection子集,并将这个子集转为ArrayList类型</td> 
  </tr> 
 </tbody> 
</table>

--------------------

#### **ArrayList添加值** ####

/**
         * 检查给定的指标范围。如果不是有效的范围,抛出一个运行时异常。
         * 这个方法不检查负参数,总是立即使用数组访问之前,
         * 抛出ArrayIndexOutOfBoundsException如果指数是负的。
         * 
         * PS:当用负数去访问一个数组下标时,数组就后throw new IndexOutOfBoundsException
         */
        private void rangeCheck(int index) {
            if (index >= size)
                throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
        }
    
        /**
         * 替换元素在这个列表中指定的位置指定的元素。
         * @param指数指数的元素来代替
         * @param元素元素存储在指定的位置 
         * @return元素之前指定的位置 
         * @throws IndexOutOfBoundsException {
          @inheritDoc }
         */
        public E set(int index, E element) {
            rangeCheck(index);
    
            E oldValue = elementData(index);
            elementData[index] = element;
            return oldValue;
        }
    
        /**
         * 将指定的元素添加到列表尾部。
         * @param e 元素附加到这个列表
         * @return  成功返回true  {
          @linkCollection  add方法})
         */
        public boolean add(E e) {
            ensureCapacityInternal(size + 1);  // Increments modCount!!
            elementData[size++] = e;
            return true;
        }
    
    
        /**
         * 通过添加和addAll rangeCheck版本使用。
         * 
         * PS:在这里验证了index是否为负数
         */
        private void rangeCheckForAdd(int index) {
            if (index > size || index < 0)
                throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
        }
    
    
    
        /**
         * 在指定位置插入指定的元素列表。
         * 变化的元素目前位置(如果有的话)
         * 任何后续元素向右(添加一个索引)。PS:要注意这句,这也是为什么相效于LinkedList插入对象时效率低的原因.
         * @param指数的指数是插入指定元素 
         * @param要插入元素的元素 
         * @throws IndexOutOfBoundsException {
          @inheritDoc }
         */
        public void add(int index, E element) {
            rangeCheckForAdd(index);
    
            ensureCapacityInternal(size + 1);  // Increments modCount!!
            System.arraycopy(elementData, index, elementData, index + 1,
                             size - index);
            elementData[index] = element;
            size++;
        }
    
    
    
    
        /**
         * 附加的所有元素在指定集合的末尾
         * 这个列表的顺序返回的指定集合的迭代器。
         * 这个操作的行为未定义的操作时,如果指定的集合被修改在进步。
         * (这意味着这个调用的行为定义如果这个列表指定的集合,这列表非空的。)
         * 
         * @param c collection containing elements to be added to this list
         * @return <tt>true</tt> if this list changed as a result of the call
         * @throws NullPointerException if the specified collection is null
       */
        public boolean addAll(Collection<? extends E> c) {
            Object[] a = c.toArray();
            int numNew = a.length;
            ensureCapacityInternal(size + numNew);  // Increments modCount
            System.arraycopy(a, 0, elementData, size, numNew);
            size += numNew;
            return numNew != 0;
        }
    
        /**
         * 
         * 从指定的位置将指定集合中的所有元素插入列表。
         * 变化的元素目前这个位置(如果有的话)和任何后续的元素
         * 正确的(增加他们的下标)。新元素就会出现的顺序在列表中返回的
         * 指定集合的迭代器。
         * @param index index at which to insert the first element from the
         *              specified collection
         * @param c collection containing elements to be added to this list
         * @return <tt>true</tt> if this list changed as a result of the call
         * @throws IndexOutOfBoundsException {@inheritDoc}
         * @throws NullPointerException if the specified collection is null
         */
        public boolean addAll(int index, Collection<? extends E> c) {
            rangeCheckForAdd(index);
    
            Object[] a = c.toArray();
            int numNew = a.length;
            ensureCapacityInternal(size + numNew);  // Increments modCount
    
            int numMoved = size - index;
            if (numMoved > 0)
                System.arraycopy(elementData, index, elementData, index + numNew,
                                 numMoved);
    
            System.arraycopy(a, 0, elementData, index, numNew);
            size += numNew;
            return numNew != 0;
        }

关于上面的代码验证index

private void rangeCheckForAdd(int index) {
            if (index > size || index < 0) // PS:在这里验证了index是否为负数
                throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
        }
        private void rangeCheck(int index) {
            if (index >= size) // PS:当用负数去访问一个数组下标时,数组就后throw new IndexOutOfBoundsException
                throw new IndexOutOfBoundsException(outOfBoundsMsg(index));
        }
        这里有验证index思想没有统一,估计是两个人写的两个方法,在看看ArrayList的作者  
        @author  Josh Bloch
        @author  Neal Gafter
        这里纯属猜测 .

--------------------

#### **ArrayList 取值** ####

/**
         * 返回此列表的元素在指定的位置.
         *
         * @param  index index of the element to return
         * @return the element at the specified position in this list
         * @throws IndexOutOfBoundsException {@inheritDoc}
         */
        public E get(int index) {
            rangeCheck(index);
    
            return elementData(index);
        }

--------------------

### **LinkedList** ###

基于链表的数据结构。  
LinkedList中的get方法是按照顺序从列表的一端开始检查,直到另结尾 .  
LinkedList类是双向列表,列表中的每个节点都包含了对前一个和后一个元素的引用.  
LinkedList实现Deque ,间接实现Queue .  
对于新增和删除操作add和remove，LinedList比较占优势，因为ArrayList要移动数据。

#### **LinkedList 私有属性** ####

public class LinkedList<E>
        extends AbstractSequentialList<E>
        implements List<E>, Deque<E>, Cloneable, java.io.Serializable
    {
        
    
        private static class Node<E> {
        
            E item;
            Node<E> next;
            Node<E> prev;
    
            Node(Node<E> prev, E element, Node<E> next) {
                this.item = element;
                this.next = next;
                this.prev = prev;
            }
        }
    
        transient int size = 0;
    
        /**
         * Pointer to first node.
         * Invariant: (first == null && last == null) ||
         *            (first.prev == null && first.item != null)
         */
        transient Node<E> first;
    
        /**
         * Pointer to last node.
         * Invariant: (first == null && last == null) ||
         *            (last.next == null && last.item != null)
         */
        transient Node<E> last;
    
    
    }

**相较于ArrayList , LinkedList要有趣的多,它的first 与 last 两个节点属性是Node的静态内部类,这也证明了LinkedArrayList 是一个双向链表的数据结构 .  
transient 关键字使属性在序列化时被忽略 .**

#### **LinkedList构造方法** ####

/**
         * Constructs an empty list.
         */
        public LinkedList() {
        }
    
        /**
         * 构造一个包含指定的元素列表Collection,它们的顺序返回的Collection迭代器.
         *
         * @param  c the collection whose elements are to be placed into this list
         * @throws NullPointerException if the specified collection is null
         */
        public LinkedList(Collection<? extends E> c) {
            this();
            addAll(c);
        }

<table> 
 <thead> 
  <tr> 
   <th>构造方法</th> 
   <th align="left"></th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>LinkedList()</td> 
   <td align="left">也就是一个空的LinkedList 有 first 与 last 两个属性</td> 
  </tr> 
  <tr> 
   <td>LinkedList(Collection c)</td> 
   <td align="left">接受一个Collection子集,并将这个子集转为LinkedList类型</td> 
  </tr> 
 </tbody> 
</table>

关于Collection子集上面简单的介绍过了.

#### **LinkedList添加值** ####

/**
         * Inserts the specified element at the beginning of this list.
         * 添加一个指定的对象到头
         * @param e the element to add
         */
        public void addFirst(E e) {
            linkFirst(e);
        }
    
        /**
         * Appends the specified element to the end of this list.
         * 添加一个指定的对象到尾
         * <p>This method is equivalent to {@link #add}.
         *
         * @param e the element to add
         */
        public void addLast(E e) {
            linkLast(e);
        }
    
    
        /**
         * Links e as last element.
         */
        void linkLast(E e) {
            final Node<E> l = last;
            final Node<E> newNode = new Node<>(l, e, null);
            last = newNode;
            if (l == null)
                first = newNode;
            else
                l.next = newNode;
            size++;
            modCount++;
        }
    
        /**
         * Appends the specified element to the end of this list.
         * 添加一个指定的对象到尾
         * <p>This method is equivalent to {@link #addLast}.
         *
         * @param e element to be appended to this list
         * @return {@code true} (as specified by {@link Collection#add})
         */
        public boolean add(E e) {
            linkLast(e);
            return true;
        }
    
        /**
         * 附加的所有元素在指定集合的末尾
         * 这个列表的顺序指定返回的集合的迭代器。
         * 这个操作的行为是未定义的指定的集合操作时被修改进步。
         * (注意,这将发生如果指定的集合这个列表,非空的)。
         *
         * @param c collection containing elements to be added to this list
         * @return {@code true} if this list changed as a result of the call
         * @throws NullPointerException if the specified collection is null
         */
        public boolean addAll(Collection<? extends E> c) {
            return addAll(size, c);
        }
    
        /**
         * 从指定的位置将指定集合中的所有元素插入列表。
         * 变化的元素目前这个位置(如果有的话)和任何后续的元素正确的(增加他们的指标)。
         * 新元素就会出现的顺序在列表中返回的指定集合的迭代器。
         *
         * @param index index at which to insert the first element
         *              from the specified collection
         * @param c collection containing elements to be added to this list
         * @return {@code true} if this list changed as a result of the call
         * @throws IndexOutOfBoundsException {@inheritDoc}
         * @throws NullPointerException if the specified collection is null
         */
        public boolean addAll(int index, Collection<? extends E> c) {
            checkPositionIndex(index);
    
            Object[] a = c.toArray();
            int numNew = a.length;
            if (numNew == 0)
                return false;
    
            Node<E> pred, succ;
            if (index == size) {
                succ = null;
                pred = last;
            } else {
                succ = node(index);
                pred = succ.prev;
            }
    
            for (Object o : a) {
                @SuppressWarnings("unchecked") E e = (E) o;
                Node<E> newNode = new Node<>(pred, e, null);
                if (pred == null)
                    first = newNode;
                else
                    pred.next = newNode;
                pred = newNode;
            }
    
            if (succ == null) {
                last = pred;
            } else {
                pred.next = succ;
                succ.prev = pred;
            }
    
            size += numNew;
            modCount++;
            return true;
        }
        /**
         * 替换的元素在这个列表的指定位置指定元素。
         *
         * @param index index of the element to replace
         * @param element element to be stored at the specified position
         * @return the element previously at the specified position
         * @throws IndexOutOfBoundsException {@inheritDoc}
         */
        public E set(int index, E element) {
            checkElementIndex(index);
            Node<E> x = node(index);
            E oldVal = x.item;
            x.item = element;
            return oldVal;
        }
    
        /**
         * 在指定位置插入指定元素在这个列表中。
         * 转变当前元素(如果有的话)和任何位置
         * 后续元素向右(添加一个索引)。
         * 
         * PS : 相效于ArrayList 要移动index后所有的元素 LinkedList 要高效很多. 
         *
         * @param index index at which the specified element is to be inserted
         * @param element element to be inserted
         * @throws IndexOutOfBoundsException {@inheritDoc}
         */
        public void add(int index, E element) {
            checkPositionIndex(index);
    
            if (index == size)
                linkLast(element);
            else
                linkBefore(element, node(index));
        }
    
        /**
         * 之前插入元素e succ非空节点。.
         */
        void linkBefore(E e, Node<E> succ) {
            // assert succ != null;
            final Node<E> pred = succ.prev;
            final Node<E> newNode = new Node<>(pred, e, succ);
            succ.prev = newNode;
            if (pred == null)
                first = newNode;
            else
                pred.next = newNode;
            size++;
            modCount++;
        }
    
    
        /**
         * 添加一个元素到头.
         *
         * <p>This method is equivalent to {@link #addFirst}.
         *
         * @param e the element to push
         * @since 1.6
         */
        public void push(E e) {
            addFirst(e);
        }

#### **LinkedList 取值** ####

/**
         * 返回头元素.
         *
         * @return the first element in this list
         * @throws NoSuchElementException if this list is empty
         */
        public E getFirst() {
            final Node<E> f = first;
            if (f == null)
                throw new NoSuchElementException();
            return f.item;
        }
    
        /**
         * 返回尾元素.
         *
         * @return the last element in this list
         * @throws NoSuchElementException if this list is empty
         */
        public E getLast() {
            final Node<E> l = last;
            if (l == null)
                throw new NoSuchElementException();
            return l.item;
        }
    
        /**
         * 通过下标得到元素.
         *
         * @param index index of the element to return
         * @return the element at the specified position in this list
         * @throws IndexOutOfBoundsException {@inheritDoc}
         */
        public E get(int index) {
            checkElementIndex(index);
            return node(index).item;
        }
        /**
         * node方法通过下标得到元素
         * 
         * PS : 第一次进入方法用到一个二分,之后就是for,其实可以改为二分查找 .
         */
        Node<E> node(int index) {
            // assert isElementIndex(index);
    
            if (index < (size >> 1)) {
                Node<E> x = first;
                for (int i = 0; i < index; i++)
                    x = x.next;
                return x;
            } else {
                Node<E> x = last;
                for (int i = size - 1; i > index; i--)
                    x = x.prev;
                return x;
            }
        }
    
        /**
         * 返回头元素.
         *
         * @return the head of this list, or {@code null} if this list is empty
         * @since 1.5
         */
        public E peek() {
            final Node<E> f = first;
            return (f == null) ? null : f.item;
        }
    
        /**
         * 返回头元素.
         *
         * @return the head of this list
         * @throws NoSuchElementException if this list is empty
         * @since 1.5
         */
        public E element() {
            return getFirst();
        }
    
        /**
         * 取得头元素, 并将头元素删除 , 将第二个元素作为头元素
         * @return the head of this list, or {@code null} if this list is empty
         * @since 1.5
         */
        public E poll() {
            final Node<E> f = first;
            return (f == null) ? null : unlinkFirst(f);
        }
        /**
         *
         * 取得头元素 
         * 
         * PS : 此方法与 1.5 peek方法内容一至 
         * 
         * @return the first element of this list, or {@code null}
         *         if this list is empty
         * @since 1.6
         */
        public E peekFirst() {
            final Node<E> f = first;
            return (f == null) ? null : f.item;
         }
    
        /**
         * 取得尾元素 .
         *
         * @return the last element of this list, or {@code null}
         *         if this list is empty
         * @since 1.6
         */
        public E peekLast() {
            final Node<E> l = last;
            return (l == null) ? null : l.item;
        }
    
        /**
         * 取头,删除头,第二个元素做为头元素.
         *
         * @return the first element of this list, or {@code null} if
         *     this list is empty
         * @since 1.6
         */
        public E pollFirst() {
            final Node<E> f = first;
            return (f == null) ? null : unlinkFirst(f);
        }
    
        /**
         * 取尾,删除尾,倒数第二个元素做为尾元素..
         *
         * @return the last element of this list, or {@code null} if
         *     this list is empty
         * @since 1.6
         */
        public E pollLast() {
            final Node<E> l = last;
            return (l == null) ? null : unlinkLast(l);
        }

--------------------

### ArrayList LinkedList 性能比较 ###

package com.cn.mark.java.util;
    
    import java.util.*;
    
    /**
     * Created by mark on 5/22/16.
     */
    public class ListTest {
    
    
        private static int N  = 50000;
    
        private static List values;
    
        private static int list_size ;
    
        static Random r = new Random();
    
    
        //add
        static long test_ArrayList_add_first(ArrayList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.add(0, i);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_add_first(LinkedList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.addFirst(i);
            return System.currentTimeMillis() - start;
        }
    
        static long test_ArrayList_add_last(ArrayList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.add(i);//ArrayList 默认加在尾
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_add_last(LinkedList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.addLast(i);
            return System.currentTimeMillis() - start;
        }
    
        static long test_ArrayList_add_random(ArrayList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.add(r.nextInt(N), 1);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_add_random(LinkedList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.add(r.nextInt(N), 1);
            return System.currentTimeMillis() - start;
        }
    
    
        //del
        static long test_ArrayList_del_first(ArrayList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.remove(0);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_del_first(LinkedList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.remove();// 默认删除头
            return System.currentTimeMillis() - start;
        }
    
        static long test_ArrayList_del_last(ArrayList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.remove(list.size()-1);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_del_last(LinkedList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.removeLast();
            return System.currentTimeMillis() - start;
        }
    
        static long test_ArrayList_del_random(ArrayList list){
            long start = System.currentTimeMillis();
            list_size = list.size();
            for (int i = 0; i < list_size; i++){
                list_size = list.size();
                list.remove(r.nextInt(list_size - 1));
            }
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_del_random(LinkedList list){
            long start = System.currentTimeMillis();
            list_size = list.size();
            for (int i = 0; i < list_size; i++){
                list_size = list.size();
                list.remove(r.nextInt(list_size - 1));
            }
            return System.currentTimeMillis() - start;
        }
    
    
        //modifier
        static long test_ArrayList_set_random(ArrayList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.set(r.nextInt(N), 1);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_set_random(LinkedList list){
            long start = System.currentTimeMillis();
            for (int i = 0; i <  N; i++)
                list.set(r.nextInt(N), 1);
            return System.currentTimeMillis() - start;
        }
    
    
        //query
        static long test_ArrayList_get_first(ArrayList list) {
            long start = System.currentTimeMillis();
            for (int i = 0; i < N; i++)
                list.get(i);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_get_first(LinkedList list) {
            long start = System.currentTimeMillis();
            for (int i = 0; i < N; i++)
                list.poll();
            return System.currentTimeMillis() - start;
        }
    
        static long test_ArrayList_get_last(ArrayList list) {
            long start = System.currentTimeMillis();
            for (int i = N-1; i >0; i--)
                list.get(i);
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_get_last(LinkedList list) {
            long start = System.currentTimeMillis();
            for (int i = 0; i < N; i++)
                list.pollLast();
            return System.currentTimeMillis() - start;
        }
    
        static long test_ArrayList_get_random(ArrayList list) {
            long start = System.currentTimeMillis();
            for (int i = 0; i < N; i++)
                list.get(r.nextInt(N));
            return System.currentTimeMillis() - start;
        }
        static long test_LinkedList_get_random(LinkedList list) {
            long start = System.currentTimeMillis();
            for (int i = 0; i < N; i++)
                list.get(r.nextInt(N));
            return System.currentTimeMillis() - start;
        }
    
    
        public static void main(String[] args) {
    
            Long vals[] = new Long[N];
    
            Random r = new Random();
    
            for (int i = 0, currval = 0; i < N; i++) {
                vals[i] = new Long(currval);
                currval += r.nextInt(100) + 1;
            }
    
            values = Arrays.asList(vals);
    
    
            // add
            System.out.println("test_ArrayList_add_first \t" + test_ArrayList_add_first(new ArrayList(values)));
            System.out.println("test_LinkedList_add_first \t" + test_LinkedList_add_first(new LinkedList(values)));
            System.out.println();
    
            System.out.println("test_ArrayList_add_last \t" + test_ArrayList_add_last(new ArrayList(values)));
            System.out.println("test_LinkedList_add_last \t" + test_LinkedList_add_last(new LinkedList(values)));
            System.out.println();
    
            System.out.println("test_ArrayList_add_random \t" + test_ArrayList_add_random(new ArrayList(values)));
            System.out.println("test_LinkedList_add_random \t" + test_LinkedList_add_random(new LinkedList(values)));
            System.out.println();
    
    
            //del
            System.out.println("test_ArrayList_del_first \t" + test_ArrayList_del_first(new ArrayList(values)));
            System.out.println("test_LinkedList_del_first \t" + test_LinkedList_del_first(new LinkedList(values)));
            System.out.println();
    
            System.out.println("test_ArrayList_del_last \t" + test_ArrayList_del_last(new ArrayList(values)));
            System.out.println("test_LinkedList_del_last \t" + test_LinkedList_del_last(new LinkedList(values)));
            System.out.println();
    
            System.out.println("test_ArrayList_del_random \t" + test_ArrayList_del_random(new ArrayList(values)));
            System.out.println("test_LinkedList_del_random \t" + test_LinkedList_del_random(new LinkedList(values)));
            System.out.println();
    
            //modifier
            System.out.println("test_ArrayList_set_random \t" + test_ArrayList_set_random(new ArrayList(values)));
            System.out.println("test_LinkedList_set_random \t" + test_LinkedList_set_random(new LinkedList(values)));
            System.out.println();
    
    
            //query
            System.out.println("test_ArrayList_get_first \t" + test_ArrayList_get_first(new ArrayList(values)));
            System.out.println("test_LinkedList_get_first \t" + test_LinkedList_get_first(new LinkedList(values)));
            System.out.println();
    
            System.out.println("test_ArrayList_get_last \t" + test_ArrayList_get_last(new ArrayList(values)));
            System.out.println("test_LinkedList_get_last \t" + test_LinkedList_get_last(new LinkedList(values)));
            System.out.println();
            System.out.println("test_ArrayList_get_random \t" + test_ArrayList_get_random(new ArrayList(values)));
            System.out.println("test_LinkedList_get_random \t" + test_LinkedList_get_random(new LinkedList(values)));
    
        }
    }

### 运行结果 ###

test_ArrayList_add_first    833
    test_LinkedList_add_first   8
    
    test_ArrayList_add_last     7
    test_LinkedList_add_last    10
    
    test_ArrayList_add_random   455
    test_LinkedList_add_random  7905
    
    test_ArrayList_del_first    223
    test_LinkedList_del_first   5
    
    test_ArrayList_del_last     3
    test_LinkedList_del_last    4
    
    test_ArrayList_del_random   69
    test_LinkedList_del_random  713
    
    test_ArrayList_set_random   4
    test_LinkedList_set_random  1303
    
    test_ArrayList_get_first    2
    test_LinkedList_get_first   2
    
    test_ArrayList_get_last     2
    test_LinkedList_get_last    3
    
    test_ArrayList_get_random   3
    test_LinkedList_get_random  1299
    
    Process finished with exit code 0

[20160523235117428]: /images/20220722/1ed7b1133a4541e9a9244086bc0a4bdf.png