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.logging.log4j.util;
19
20 import java.io.OutputStream;
21 import java.io.PrintWriter;
22 import java.io.Writer;
23 import java.util.Objects;
24
25 /**
26 * PrintWriter-based logging utility for classes too low level to use {@link org.apache.logging.log4j.status.StatusLogger}.
27 * Such classes cannot use StatusLogger as StatusLogger or {@link org.apache.logging.log4j.simple.SimpleLogger} depends
28 * on them for initialization. Other framework classes should stick to using StatusLogger.
29 *
30 * @since 2.6
31 */
32 final class LowLevelLogUtil {
33
34 private static PrintWriter writer = new PrintWriter(System.err, true);
35
36 /**
37 * Logs the given message.
38 *
39 * @param message the message to log
40 * @since 2.9.2
41 */
42 public static void log(final String message) {
43 if (message != null) {
44 writer.println(message);
45 }
46 }
47
48 public static void logException(final Throwable exception) {
49 if (exception != null) {
50 exception.printStackTrace(writer);
51 }
52 }
53
54 public static void logException(final String message, final Throwable exception) {
55 log(message);
56 logException(exception);
57 }
58
59 /**
60 * Sets the underlying OutputStream where exceptions are printed to.
61 *
62 * @param out the OutputStream to log to
63 */
64 public static void setOutputStream(final OutputStream out) {
65 LowLevelLogUtil.writer = new PrintWriter(Objects.requireNonNull(out), true);
66 }
67
68 /**
69 * Sets the underlying Writer where exceptions are printed to.
70 *
71 * @param writer the Writer to log to
72 */
73 public static void setWriter(final Writer writer) {
74 LowLevelLogUtil.writer = new PrintWriter(Objects.requireNonNull(writer), true);
75 }
76
77 private LowLevelLogUtil() {
78 }
79 }