hotfix/source/openejb-core/src.original/main/java/org/apache/openejb/util/ArrayStack.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.openejb.util;

import java.util.ArrayList;
import java.util.EmptyStackException;

public final class ArrayStack extends ArrayList implements Stack {

    public void setSize(int newSize) {
        if (newSize == 0) clear();
        else {
            for (int i = size() - 1; i >= newSize; i--)
                remove(i);
        }
    }

    public Object push(Object item) {
        add(item);
        return item;
    }

    public Object pop() {
        Object obj;
        obj = peek();

        int len = size();
        remove(len - 1);

        return obj;
    }

    public Object peek() {
        int len = size();

        if (len == 0) throw new EmptyStackException();

        return get(len - 1);
    }
}