1 /*
2 * Licensed to the Apache Software Foundation (ASF) under one or more
3 * contributor license agreements. See the NOTICE file distributed with
4 * this work for additional information regarding copyright ownership.
5 * The ASF licenses this file to You under the Apache License, Version 2.0
6 * (the "License"); you may not use this file except in compliance with
7 * the License. You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17 package org.apache.commons.vfs2.provider;
18
19 import java.util.ArrayList;
20 import java.util.stream.Stream;
21
22 import org.apache.commons.vfs2.FileSystemException;
23
24 /**
25 * A {@link VfsComponent} that contains a set of sub-components.
26 */
27 public abstract class AbstractVfsContainer extends AbstractVfsComponent {
28
29 /**
30 * The components contained by this component.
31 */
32 private final ArrayList<Object> components = new ArrayList<>(); // @GuardedBy("self")
33
34 /**
35 * Adds a sub-component to this component.
36 * <p>
37 * If the sub-component implements {@link VfsComponent}, it is initialized. All sub-components are closed when this
38 * component is closed.
39 * </p>
40 *
41 * @param component the component to add.
42 * @throws FileSystemException if any error occurs.
43 */
44 protected void addComponent(final Object component) throws FileSystemException {
45 synchronized (components) {
46 if (!components.contains(component)) {
47 // Initialize
48 if (component instanceof VfsComponent) {
49 final VfsComponent../org/apache/commons/vfs2/provider/VfsComponent.html#VfsComponent">VfsComponent vfsComponent = (VfsComponent) component;
50 vfsComponent.setLogger(getLogger());
51 vfsComponent.setContext(getContext());
52 vfsComponent.init();
53 }
54
55 // Keep track of component, to close it later
56 components.add(component);
57 }
58 } // synchronized
59 }
60
61 /**
62 * Removes a sub-component from this component.
63 *
64 * @param component the component to remove.
65 */
66 protected void removeComponent(final Object component) {
67 synchronized (components) {
68 // multiple instances should not happen
69 components.remove(component);
70 }
71 }
72
73 /**
74 * Closes the sub-components of this component.
75 */
76 @Override
77 public void close() {
78 final Object[] toclose;
79 synchronized (components) {
80 toclose = components.toArray();
81 components.clear();
82 }
83
84 // Close all components
85 Stream.of(toclose).filter(component -> component instanceof VfsComponent)
86 .forEach(component -> ((VfsComponent) component).close());
87 }
88 }