1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * https://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing,
13 * software distributed under the License is distributed on an
14 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15 * KIND, either express or implied. See the License for the
16 * specific language governing permissions and limitations
17 * under the License.
18 */
19 package org.apache.bcel.util;
20
21 import java.util.Stack;
22
23 import org.apache.bcel.classfile.JavaClass;
24
25 /**
26 * Utility class implementing a (typesafe) stack of JavaClass objects.
27 *
28 * @see Stack
29 */
30 public class ClassStack {
31
32 private final Stack<JavaClass> stack = new Stack<>();
33
34 /**
35 * Constructs a new ClassStack.
36 */
37 public ClassStack() {
38 }
39
40 /**
41 * Checks if the stack is empty.
42 *
43 * @return true if the stack is empty.
44 */
45 public boolean empty() {
46 return stack.empty();
47 }
48
49 /**
50 * Pops a JavaClass from the stack.
51 *
52 * @return the JavaClass from the top of the stack.
53 */
54 public JavaClass pop() {
55 return stack.pop();
56 }
57
58 /**
59 * Pushes a JavaClass onto the stack.
60 *
61 * @param clazz the JavaClass to push.
62 */
63 public void push(final JavaClass clazz) {
64 stack.push(clazz);
65 }
66
67 /**
68 * Gets the top JavaClass from the stack without removing it.
69 *
70 * @return the JavaClass at the top of the stack.
71 */
72 public JavaClass top() {
73 return stack.peek();
74 }
75 }