Java链表之基础应用

class Book{ //创建book 类
	private String title;
	private double price;
	public Book(String title, double price){
		this.title = title;
		this.price = price;
	}
	public String getInfo(){
		return "图书名称：" + this.title + "，图书价格：" + this.price;
	}
	public boolean compare(Book book){ //比较方法
		if(this == book){
			return true;
		}
		if(book == null){
			return false;
		}
		if(this.title.equals(book.title) && this.price == book.price){
			return true;
		}
		return false;
	}
}
class Link{
	private class Node{
		private Book data;
		private Node next;
		public Node(Book data){
			this.data = data;
		}
		public void addNode(Node newNode){ //增加方法
			if(this.next == null){
				this.next  = newNode;
			}else{
				this.next.addNode(newNode);
			}
		}	
		public boolean containsNode(Book data){ //根据内容查询数据
			if(data.compare(this.data)){
				return  true; //后面不再查询
			}
			else{
				if(this.next != null){//有后续节点，继续查询
					return this.next.containsNode(data);
				}// 没有后续节点 ， 返回false
				else{
					return false;
				}
			}
		}
		public Book getNode(int index){//查询指定索引内容
			if(Link.this.foot++ == index){  //不相等自动进行下一个
				return this.data;
			}else{
				return this.next.getNode(index);
			}
		}
		public void setNode(int index,Book data){ // 修改指定索引的内容
			if(Link.this.foot++ == index){
				this.data = data;
			}else{
				this.next.setNode(index, data);
			}
		}
		public void removeNode(Node previous,Book data){ //处理非根节点的删除
			if(data.compare(this.data)){	//当前节点就是要删除的节点
				previous.next = this.next; //上一个节点直接指向下一个节点
			}else{
				this.next.removeNode(previous.next, data);
			}
		}
		public Book [] toArrayNode(){//转化为对象数组进行输出
			Link.this.retArray[Link.this.foot ++] = this.data;
			if(this.next != null){
				this.next.toArrayNode();
			}
			return null;
		}
	}
	//===============以上为内部类============
	private Node root;
	private int foot = 0; // 索引
	private int count = 0;//保存元素个数
	private Book[] retArray;
	public void add(Book data){ //数据增加
		if(data == null) //为空不保存
			return ;
		Node newNode = new Node(data);
		if(this.root == null){
			this.root = newNode;
		}else{
			this.root.addNode(newNode); //增加判断转到Node()类
		}
		this.count++;
	}
	public int size(){ //取得保存的数据量
		return this.count;
	}
	public boolean isEmpty(){ //判断链表是否为空
		return this.count==0;
	} 
	public boolean contains(Book data){ //查询
		//没有查询结果或者根节点没数据
		if(data == null || this.root == null)
			return false;
		return this.root.containsNode(data);
	}
	public Book get(int index){ //查询指定索引的内容
		this.foot = 0;
		if(index > count)
			return null;//没有数据
		else
			return this.root.getNode(index);
	}
	public void set(int index,Book data){ //修改指定索引内容
		this.foot = 0;
		if(index > this.count)
			return ; //结束
		else
			this.root.setNode(index,data);
	}
	public void remove(Book data){  // 删除指定内容的节点
		if(this.contains(data)){	//contains保证数据存在
			if(data.compare(this.root.data)){	//删除的为根节点
				this.root = this.root.next;
			}else{ //不是根节点,从第二个节点开始
				this.root.next.removeNode(this.root, data);
			}
			this.count --;  //删除后个数-1
		}
	}
	public Book [] toArray(){  //转化为对象数组进行输出(重要)
		if(this.root == null){
			return null;
		}else{
			this.foot = 0;
			this.retArray  = new Book[this.count]; //开辟内存
			this.root.toArrayNode();
		}
		return this.retArray;
	}
}
public class Demo1 {
	public static void main(String[] args) {
		
		//测试
		Link link = new Link();
		link.add(new Book("Java开发",78.5));
		link.add(new Book("Web前端",59.5));
		link.add(new Book("JSP开发",85));
		System.out.println("共保存书籍" + link.size()); //共保存书籍
		System.out.println(link.contains(new Book("Web前端",59.5))); //查询书籍
		link.remove(new Book("JSP开发",85)); //删除书籍
		System.out.println("共保存书籍" + link.size()); //共保存书籍
		Book [] books = link.toArray(); //转化到对象数组进行输出
		for(int i = 0 ;i < books.length; i++)
			System.out.println(books[i].getInfo());
	}
}