数据结构栈，利用栈实现字符串逆序输出

package none002;
import java.util.*;
import java.io.*;
//数据结构栈，利用栈实现字符串逆序输出
public class ReverseApp {

/**
* @param args
*/
public static void main(String[] args) throws IOException{
// TODO Auto-generated method stub

InputStreamReader isr=new InputStreamReader(System.in);
BufferedReader br=new BufferedReader(isr);
Stack  sx=new Stack(20);

System.out.println("please input words or sentence you want to reverse:");
String s=br.readLine();
for(int i=0;i<s.length();i++){
sx.push(s.charAt(i));
}
System.out.println("The result is that:");
while(!sx.isEmpty()){
System.out.print(sx.pop());
}
}

}
class Stack{
int items;
char[] arrayStack;
int s;
Stack(int  max){
s=max;
arrayStack=new char[s];
items=-1;
}
public void push(char value){
if(items==s-1) System.out.println("栈已经等于最大值了。");
else arrayStack[++items]=value;
}
public char pop(){
return arrayStack[items--];
}
public boolean isEmpty(){
return items==-1;
}
public char peek(){
if(items==-1) return 0;
else return arrayStack[items];
}
public boolean isFull(){
return items==s-1;
}
}