com.sun.xml.rpc.util.CachedStack Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
package com.sun.xml.rpc.util;
import java.util.ArrayList;
import java.util.List;
/**
* @author JAX-RPC Development Team
*/
public abstract class CachedStack {
protected List elements = new ArrayList();
protected int topOfStack = -1;
protected abstract Object createObject() throws Exception;
public void push() throws Exception {
++topOfStack;
if (elements.size() == topOfStack) {
elements.add(topOfStack, createObject());
}
}
public void pop() {
if (topOfStack < 0) {
throw new ArrayIndexOutOfBoundsException(topOfStack);
}
--topOfStack;
}
public Object peek() {
if (topOfStack == -1) {
return null;
}
return elements.get(topOfStack);
}
public int depth() {
return topOfStack + 1;
}
}