用ArrayList实现栈

public class ArrayListDemo{

	/**
	 * @param args
	 */
	//用这三种方法实现一个栈
	
	 private static  ArrayList<Object> list=new ArrayList<Object>();
	 //判断占是否为空 
	 public static boolean isStackEmpty(){ 
		 return list.isEmpty()?true:false; 
		 }
	 //入栈 
	 public static  void push(Object obj){
		 list.add(obj);
		 } 
	 //出栈
	 public static void pop(){ 
		 Object obj=null;
		 if(!list.isEmpty()){
			 obj=list.get(list.size()-1); 
			 System.out.println(obj); 
			 list.remove(obj);
			 }else{ 
				 return;
				 } 
		 } 
	 //获取栈的元素个数
	 public int getLength(){
		 return list.size(); 
	 }
	public static void main(String[] args) {
		
		
		/*LinkedListDemo.push("a"); 
		ArrayListDemo.push(2);
		ArrayListDemo.push("123"); 
		ArrayListDemo.push("ahu"); 
		//System.out.println(myStack.getLength()); 
		while(!ArrayListDemo.isStackEmpty()){ 
			ArrayListDemo.pop();
			}
}