package java_base; import java.util.concurrent.locks.ReentrantLock; public class MyLockStack { private char[] ca = new char[10]; private int point = 0; private final ReentrantLock lock = new ReentrantLock(); public int getPoint() { return point; } public char pop() { lock.lock(); char ch = '0'; try { if(this.getPoint() > 0) { point --; ch = ca[point]; } } catch (Exception e) { // TODO: handle exception }finally { lock.unlock(); return ch; } } public void push(char c) { lock.lock(); try { if(this.getPoint() < ca.length) { ca[point] = c; point ++; } } catch (Exception e) { // TODO: handle exception }finally { lock.unlock(); } } public static void main(String[] args) { // TODO Auto-generated method stub MyLockStack stack = new MyLockStack(); stack.push('A'); stack.push('B'); stack.push('C'); System.out.println(stack.pop()); System.out.println(stack.pop()); System.out.println(stack.pop()); } }