001 /* 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache license, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the license for the specific language governing permissions and 015 * limitations under the license. 016 */ 017 package org.apache.logging.log4j.core.appender; 018 019 import java.io.IOException; 020 import java.io.OutputStream; 021 022 /** 023 * Manage an OutputStream so that it can be shared by multiple Appenders and will 024 * allow appenders to reconfigure without requiring a new stream. 025 */ 026 public class OutputStreamManager extends AbstractManager { 027 028 private OutputStream os; 029 030 private byte[] footer = null; 031 032 protected OutputStreamManager(OutputStream os, String streamName) { 033 super(streamName); 034 this.os = os; 035 } 036 037 /** 038 * Create a Manager. 039 * 040 * @param name The name of the stream to manage. 041 * @param data The data to pass to the Manager. 042 * @param factory The factory to use to create the Manager. 043 * @return An OutputStreamManager. 044 */ 045 public static <T> OutputStreamManager getManager(String name, T data, 046 ManagerFactory<? extends OutputStreamManager, T> factory) { 047 return AbstractManager.getManager(name, factory, data); 048 } 049 050 /** 051 * Set the header to write when the stream is opened. 052 * @param header The header. 053 */ 054 public synchronized void setHeader(byte[] header) { 055 if (header != null) { 056 try { 057 this.os.write(header, 0, header.length); 058 } catch (IOException ioe) { 059 LOGGER.error("Unable to write header", ioe); 060 } 061 } 062 } 063 064 /** 065 * Set the footer to write when the stream is closed. 066 * @param footer The footer. 067 */ 068 public synchronized void setFooter(byte[] footer) { 069 if (footer != null) { 070 this.footer = footer; 071 } 072 } 073 074 /** 075 * Default hook to write footer during close. 076 */ 077 @Override 078 public void releaseSub() { 079 if (footer != null) { 080 write(footer); 081 } 082 close(); 083 } 084 085 /** 086 * Returns the status of the stream. 087 * @return true if the stream is open, false if it is not. 088 */ 089 public boolean isOpen() { 090 return getCount() > 0; 091 } 092 093 protected OutputStream getOutputStream() { 094 return os; 095 } 096 097 protected void setOutputStream(OutputStream os) { 098 this.os = os; 099 } 100 101 /** 102 * Some output streams synchronize writes while others do not. Synchronizing here insures that 103 * log events won't be intertwined. 104 * @param bytes The serialized Log event. 105 * @param offset The offset into the byte array. 106 * @param length The number of bytes to write. 107 * @throws AppenderRuntimeException if an error occurs. 108 */ 109 protected synchronized void write(byte[] bytes, int offset, int length) { 110 //System.out.println("write " + count); 111 try { 112 os.write(bytes, offset, length); 113 } catch (IOException ex) { 114 String msg = "Error writing to stream " + getName(); 115 throw new AppenderRuntimeException(msg, ex); 116 } 117 } 118 119 /** 120 * Some output streams synchronize writes while others do not. Synchronizing here insures that 121 * log events won't be intertwined. 122 * @param bytes The serialized Log event. 123 * @throws AppenderRuntimeException if an error occurs. 124 */ 125 protected void write(byte[] bytes) { 126 write(bytes, 0, bytes.length); 127 } 128 129 protected void close() { 130 if (os == System.out || os == System.err) { 131 return; 132 } 133 try { 134 os.close(); 135 } catch (IOException ex) { 136 LOGGER.error("Unable to close stream " + getName() + ". " + ex); 137 } 138 } 139 140 /** 141 * Flush any buffers. 142 */ 143 public void flush() { 144 try { 145 os.flush(); 146 } catch (IOException ex) { 147 String msg = "Error flushing stream " + getName(); 148 throw new AppenderRuntimeException(msg, ex); 149 } 150 } 151 }