1.1Linkedlist的方法

1.2构造方法

1.2.1特点

(1)有序，可重复

(2)底层使用双链表存储，所以查找慢（LinkedList不能随机访问，从开头或结尾遍历列表），添加和删除快（找到指定位置或者找到指定元素后，添加和删除操作快）

(3)LinkedList是非线程安全的

1.3案例：

package List;

public class BookEntity {
    private String name;
    private double price;

    public BookEntity() {
    }

    public BookEntity(String name, double price) {
        super();
        this.name = name;
        this.price = price;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public double getPrice() {
        return price;
    }

    public void setPrice(double price) {
        this.price = price;
    }

    @Override
    public String toString() {
        return "List.BookEntity [name=" + name + ", price=" + price + "]";
    }
}

package List;


import java.util.LinkedList;
import java.util.List;

class LinkListTest {
    public static void main(String[] args) {
        LinkedList<BookEntity> linkedList=new LinkedList<>();

        BookEntity be1= new BookEntity("三国演义",20);
        BookEntity be2= new BookEntity("西游记",30);
        BookEntity be3= new BookEntity("红楼梦",40);
        BookEntity be4= be3;

        linkedList.add(be1);
        linkedList.add(be2);
        linkedList.add(be3);
        linkedList.add(be4);
        System.out.println("linkedList的数量为"+linkedList.size());
        for (BookEntity be:linkedList){
            System.out.println(be);
        }

        System.out.println("==========linkedList.get(1)=======");
        System.out.println(linkedList.get(1));

        BookEntity be5=new BookEntity("水浒传",45);
        BookEntity be6=new BookEntity("聊斋",35);
        System.out.println("==========addFirst==addLast=============");
        linkedList.addFirst(be5);
        linkedList.addLast(be6);

        for (BookEntity be:linkedList){
            System.out.println(be);
        }
//查找头尾
        System.out.println("======getFirst=======getLast============");
        System.out.println(linkedList.getFirst());
        System.out.println(linkedList.getLast());

        //删除头尾
        System.out.println("======removeFirst()====removeLast()========");
        System.out.println(linkedList.removeFirst());
        System.out.println(linkedList.removeLast());
        System.out.println("---------------------");
        for (BookEntity be:linkedList){
            System.out.println(be);
        }
    }
}