用java代码编写堆栈

public class Stack {
    int[] data;
    int maxSize;
    int top;

    public Stack(int maxSize) {
       this.maxSize = maxSize;
       data = new int[maxSize];
       top = -1;
    }

    /**

     * 依次加入数据
     * @param data 要加入的数据
     * @return 添加是否成功
     */
    public boolean push(int data) {
       if(top+1== maxSize) {
           System.out.println("栈已满!");
           return false;
       }
       this.data[++top] = data;
       return true;
    }
 
    /**
       * 从栈中取出数据
     * @return 取出的数据
     */
    public int pop() throws Exception{
       if(top==-1) {
           throw new Exception("栈已空!");
       }
       return this.data[top--];
    }

     public static void main(String[] args) throws Exception {
       Stack stack=new Stack(1000);
       stack.push(1);
       stack.push(2);
       stack.push(3);
       stack.push(4);
       stack.push(5);
       while(stack.top>=0)
       {
           System.out.println(stack.pop());
       }     
    }
}