LinkedList的使用

import java.util.Iterator;
import java.util.LinkedList;
import java.util.ListIterator;

public  class Demo01 {
    public static void main(String[] args) {
        /* LinkedList的使用
           存储结构：双向链表
           
           LinkedList源码分析：
           int size;  集合的大小
           Node first;  链表的头节点
           Node last;  链表的尾节点
           
           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++;
    }
             
           private static class Node<E> {
        E item;  当前的数据
        Node<E> next;
        Node<E> prev;

        Node(Node<E> prev, E element, Node<E> next) {
            this.item = element;
            this.next = next;
            this.prev = prev;
        }
    }
         */

        //创建集合
        LinkedList linkedList = new LinkedList<>();

        //1.添加元素
        Student s1 = new Student("张三", 16);
        Student s2 = new Student("李四", 16);
        Student s3 = new Student("王五", 16);
        linkedList.add(s1);
        linkedList.add(s2);
        linkedList.add(s3);
        System.out.println("元素个数："+linkedList.size());//元素个数：3
        System.out.println(linkedList);//[Student{name='张三', age=16}, Student{name='李四', age=16}, Student{name='王五', age=16}]

        //2.删除元素
        linkedList.remove(s1);
        System.out.println("元素个数："+linkedList.size());//元素个数：2
        System.out.println(linkedList);//Student{name='李四', age=16}, Student{name='王五', age=16}]

        //3.遍历元素
          //1.for遍历
        for (int i = 0; i <linkedList.size() ; i++) {
            System.out.println(linkedList.get(i));
        }

          //2.增强for遍历
        for (Object o:
             linkedList) {
            Student s = (Student)o;
            System.out.println(s);
        }

          //3.使用迭代器
        Iterator iterator = linkedList.iterator();
        while (iterator.hasNext()){
            System.out.println(iterator.next());
        }

          //4.使用ListIterator迭代器
        ListIterator listIterator = linkedList.listIterator();
        while (listIterator.hasNext()){
            System.out.println(listIterator.next());
        }

        //4.判断
        System.out.println(linkedList.contains(s2));//true
        System.out.println(linkedList.isEmpty());//false

        //5.获取位置
        System.out.println(linkedList.indexOf(s3));//0
    }
}

public class Student {
    private String name;
    private int age;

    public Student() {

    }

    public Student(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public String getName() {
        return name;
    }

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

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    @Override
    public String toString() {
        return "Student{" +
                "name='" + name + '\'' +
                ", age=" + age +
                '}';
    }

    @Override
    public boolean equals(Object obj) {
        //1.判断是否为空
        if(obj==null){
            return false;
        }
        //2.判断是否为同一个对象
        if(obj==this){
            return  true;
        }
        //判断是否可转为Student类型
        if(obj instanceof Student){
            Student s=(Student) obj;//强转
            if(this.name.equals(s.getName())&&this.age==s.getAge()){
                return true;
            }
        }
        return false;
    }
}