スタック(1)----スタックの実装(LinkedList実装)

第4の実装スタックを補完する方法、LinkedList実装:
 

package com.matt.stack;

import java.util.*;

public class MyStack<AnyType> {
	private LinkedList<AnyType> list = new LinkedList<AnyType>();
	private int top;
	
	

	public MyStack() {
		clear();
	}

	public void clear() {
		top = -1;
		list.clear();	
	}

	public AnyType push(AnyType value){
		list.add(value);
		top++;
		return value;
	}
	
	
	public AnyType pop(){
		if(top<0) throw new NoSuchElementException();
		AnyType last = list.getLast();
		list.remove(top);
		top --;
		return last;
	}
	
	public AnyType peek(){
		return list.getLast();
	}
	
	public String toString(){
		String toStr = "[";
		for(int i=0;i<=top;i++){
			if(i==top) toStr += list.get(i) + "]";
			else toStr += list.get(i) + ",";
		}
		
		return toStr;
		
	}
	
	/**
	 * @param args
	 */
	public static void main(String[] args) {
		MyStack<Integer> stack = new MyStack<Integer>();
		//stack.peek();
		stack.push(1);
		stack.push(2);
		stack.push(3);
		System.out.println(stack);
		stack.pop();
		stack.pop();
		stack.pop();
		System.out.println(stack);
		
	}

}