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
18 package org.apache.log4j.helpers;
19
20 import org.apache.log4j.spi.ErrorCode;
21 import org.apache.log4j.spi.ErrorHandler;
22
23 import java.io.FilterWriter;
24 import java.io.Writer;
25
26
27 /**
28 * QuietWriter does not throw exceptions when things go
29 * wrong. Instead, it delegates error handling to its {@link ErrorHandler}.
30 */
31 public class QuietWriter extends FilterWriter {
32
33 protected ErrorHandler errorHandler;
34
35 public QuietWriter(Writer writer, ErrorHandler errorHandler) {
36 super(writer);
37 setErrorHandler(errorHandler);
38 }
39
40 public void write(String string) {
41 if (string != null) {
42 try {
43 out.write(string);
44 } catch (Exception e) {
45 errorHandler.error("Failed to write [" + string + "].", e,
46 ErrorCode.WRITE_FAILURE);
47 }
48 }
49 }
50
51 public void flush() {
52 try {
53 out.flush();
54 } catch (Exception e) {
55 errorHandler.error("Failed to flush writer,", e,
56 ErrorCode.FLUSH_FAILURE);
57 }
58 }
59
60
61 public void setErrorHandler(ErrorHandler eh) {
62 if (eh == null) {
63 // This is a programming error on the part of the enclosing appender.
64 throw new IllegalArgumentException("Attempted to set null ErrorHandler.");
65 } else {
66 this.errorHandler = eh;
67 }
68 }
69 }