java使用栈实现单词的逆序

/**
* 用栈实现单词逆序
* @author pipi
*
*/
public class MyStack {
private char[] elements;
private Integer index = -1; //指向第几个元素，代表栈顶元素，初始值为-1代表栈为空

public MyStack(Integer maxSize){
elements = new char[maxSize];
}

public void put(char element){
elements[++index] = element;
}

public char get(){
if(index != -1)
return elements[index--];
else
throw new RuntimeException("空栈");
}

public Integer size(){
return index + 1;
}

public static void main(String[] args) {
MyStack stack = new MyStack(100);
String a = "asdfghjkl";
for(int i = 0;i < a.length();i++)
stack.put(a.charAt(i));

Integer size = stack.size();

StringBuffer sb = new StringBuffer();
for(int
4000
i = 0;i < size;i++)
sb.append(stack.get());

System.out.println(sb.toString());
}
}