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.io.output;
18
19 import java.io.Writer;
20
21 /**
22 * Proxy writer that prevents the underlying writer from being closed.
23 * <p>
24 * This class is typically used in cases where a writer needs to be passed to a
25 * component that wants to explicitly close the writer even if other components
26 * would still use the writer for output.
27 * </p>
28 *
29 * @since 2.7
30 */
31 public class CloseShieldWriter extends ProxyWriter {
32
33 /**
34 * Constructs a proxy that shields the given writer from being closed.
35 *
36 * @param writer the writer to wrap
37 * @return the created proxy
38 * @since 2.9.0
39 */
40 public static CloseShieldWriter wrap(final Writer writer) {
41 return new CloseShieldWriter(writer);
42 }
43
44 /**
45 * Constructs a proxy that shields the given writer from being closed.
46 *
47 * @param writer underlying writer
48 * @deprecated Using this constructor prevents IDEs from warning if the
49 * underlying writer is never closed. Use {@link #wrap(Writer)}
50 * instead.
51 */
52 @Deprecated
53 public CloseShieldWriter(final Writer writer) {
54 super(writer);
55 }
56
57 /**
58 * Replaces the underlying writer with a {@link ClosedWriter} sentinel. The
59 * original writer will remain open, but this proxy will appear closed.
60 */
61 @Override
62 public void close() {
63 out = ClosedWriter.INSTANCE;
64 }
65
66 }