java定义栈

public interface StackInterface {
 public boolean isEmpty();
 public boolean isFull();
 public boolean push(Object object);
 public Object pop();
 public Object peek(); //获取栈顶元素
 }

 

public class JavaStack implements StackInterface {
	
	public Object[] table;
	public int top;
	
	/**不带参数的构造器，构造10个储存单元*/
	public JavaStack(){
		table = new Object[10];
		top = -1;
	}
	public JavaStack(int stackNum){
		table = new Object[stackNum];
		top = -1;
		
	}

	@Override
	public boolean isEmpty() {
		return (top == -1);
	}

	@Override
	public boolean isFull() {
		return (top >= table.length -1);
	}

	@Override
	public boolean push(Object object ) {
		if(!isFull()){
			
			table[++top] = new Object();
			table[top] = object;
			return true;
		}
		System.out.println("栈满，无法执行入栈操作！");
		return false;
	}

	@Override
	public Object pop() {
		Object object = null;
		if(!isEmpty()){
			object = table[top];
			table[top] = null;
			top--;
			
		}
		return object;
	}

	@Override
	public Object peek() {
		if(!isEmpty()){
			return table[top];
			
		}
		return null;
	}


}