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 }