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.layout; 018 019 import java.io.IOException; 020 import java.io.InterruptedIOException; 021 import java.io.LineNumberReader; 022 import java.io.PrintWriter; 023 import java.io.StringReader; 024 import java.io.StringWriter; 025 import java.nio.charset.Charset; 026 import java.util.ArrayList; 027 import java.util.List; 028 import java.util.Map; 029 030 import org.apache.logging.log4j.core.config.plugins.Plugin; 031 import org.apache.logging.log4j.core.config.plugins.PluginAttr; 032 import org.apache.logging.log4j.core.config.plugins.PluginFactory; 033 import org.apache.logging.log4j.core.helpers.Transform; 034 import org.apache.logging.log4j.core.LogEvent; 035 import org.apache.logging.log4j.message.Message; 036 import org.apache.logging.log4j.message.MultiformatMessage; 037 038 039 /** 040 * The output of the XMLLayout consists of a series of log4j:event 041 * elements as defined in the <a href="log4j.dtd">log4j.dtd</a>. If configured to do so it will 042 * output a complete well-formed XML file. The output is designed to be 043 * included as an <em>external entity</em> in a separate file to form 044 * a correct XML file. 045 * <p/> 046 * <p>For example, if <code>abc</code> is the name of the file where 047 * the XMLLayout ouput goes, then a well-formed XML file would be: 048 * <p/> 049 * <pre> 050 * <?xml version="1.0" ?> 051 * 052 * <!DOCTYPE log4j:eventSet SYSTEM "log4j.dtd" [<!ENTITY data SYSTEM "abc">]> 053 * 054 * <log4j:eventSet version="1.2" xmlns:log4j="http://logging.apache.org/log4j/"> 055 * &data; 056 * </log4j:eventSet> 057 * </pre> 058 * <p/> 059 * <p>This approach enforces the independence of the XMLLayout and the 060 * appender where it is embedded. 061 * <p/> 062 * <p>The <code>version</code> attribute helps components to correctly 063 * intrepret output generated by XMLLayout. The value of this 064 * attribute should be "1.1" for output generated by log4j versions 065 * prior to log4j 1.2 (final release) and "1.2" for relase 1.2 and 066 * later. 067 * <p/> 068 * Appenders using this layout should have their encoding 069 * set to UTF-8 or UTF-16, otherwise events containing 070 * non ASCII characters could result in corrupted 071 * log files. 072 */ 073 @Plugin(name = "XMLLayout", type = "Core", elementType = "layout", printObject = true) 074 public class XMLLayout extends AbstractStringLayout { 075 076 private static final int DEFAULT_SIZE = 256; 077 078 private static final String[] FORMATS = new String[] {"xml"}; 079 080 private final boolean locationInfo; 081 private final boolean properties; 082 private final boolean complete; 083 084 protected XMLLayout(boolean locationInfo, boolean properties, boolean complete, Charset charset) { 085 super(charset); 086 this.locationInfo = locationInfo; 087 this.properties = properties; 088 this.complete = complete; 089 } 090 091 /** 092 * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the log4j.dtd. 093 * 094 * @param event The LogEvent. 095 * @return The XML representation of the LogEvent. 096 */ 097 public String toSerializable(final LogEvent event) { 098 StringBuilder buf = new StringBuilder(DEFAULT_SIZE); 099 100 // We yield to the \r\n heresy. 101 102 buf.append("<log4j:event logger=\""); 103 String name = event.getLoggerName(); 104 if (name.length() == 0) { 105 name = "root"; 106 } 107 buf.append(Transform.escapeTags(name)); 108 buf.append("\" timestamp=\""); 109 buf.append(event.getMillis()); 110 buf.append("\" level=\""); 111 buf.append(Transform.escapeTags(String.valueOf(event.getLevel()))); 112 buf.append("\" thread=\""); 113 buf.append(Transform.escapeTags(event.getThreadName())); 114 buf.append("\">\r\n"); 115 116 Message msg = event.getMessage(); 117 if (msg != null) { 118 boolean xmlSupported = false; 119 if (msg instanceof MultiformatMessage) { 120 String[] formats = ((MultiformatMessage) msg).getFormats(); 121 for (String format : formats) { 122 if (format.equalsIgnoreCase("XML")) { 123 xmlSupported = true; 124 } 125 } 126 } 127 if (xmlSupported) { 128 buf.append("<log4j:message>"); 129 buf.append(((MultiformatMessage) msg).getFormattedMessage(FORMATS)); 130 buf.append("</log4j:message>"); 131 } else { 132 buf.append("<log4j:message><![CDATA["); 133 // Append the rendered message. Also make sure to escape any 134 // existing CDATA sections. 135 Transform.appendEscapingCDATA(buf, event.getMessage().getFormattedMessage()); 136 buf.append("]]></log4j:message>\r\n"); 137 } 138 } 139 140 if (event.getContextStack().getDepth() > 0) { 141 buf.append("<log4j:NDC><![CDATA["); 142 Transform.appendEscapingCDATA(buf, event.getContextStack().toString()); 143 buf.append("]]></log4j:NDC>\r\n"); 144 } 145 146 Throwable throwable = event.getThrown(); 147 if (throwable != null) { 148 List<String> s = getThrowableString(throwable); 149 buf.append("<log4j:throwable><![CDATA["); 150 for (String str : s) { 151 Transform.appendEscapingCDATA(buf, str); 152 buf.append("\r\n"); 153 } 154 buf.append("]]></log4j:throwable>\r\n"); 155 } 156 157 if (locationInfo) { 158 StackTraceElement element = event.getSource(); 159 buf.append("<log4j:locationInfo class=\""); 160 buf.append(Transform.escapeTags(element.getClassName())); 161 buf.append("\" method=\""); 162 buf.append(Transform.escapeTags(element.getMethodName())); 163 buf.append("\" file=\""); 164 buf.append(Transform.escapeTags(element.getFileName())); 165 buf.append("\" line=\""); 166 buf.append(element.getLineNumber()); 167 buf.append("\"/>\r\n"); 168 } 169 170 if (properties && event.getContextMap().size() > 0) { 171 buf.append("<log4j:properties>\r\n"); 172 for (Map.Entry<String, String> entry : event.getContextMap().entrySet()) { 173 buf.append("<log4j:data name=\""); 174 buf.append(Transform.escapeTags(entry.getKey())); 175 buf.append("\" value=\""); 176 buf.append(Transform.escapeTags(String.valueOf(entry.getValue()))); 177 buf.append("\"/>\r\n"); 178 } 179 buf.append("</log4j:properties>\r\n"); 180 } 181 182 buf.append("</log4j:event>\r\n\r\n"); 183 184 return buf.toString(); 185 } 186 187 /** 188 * Returns appropriate XML headers. 189 * @return a byte array containing the header. 190 */ 191 @Override 192 public byte[] getHeader() { 193 if (!complete) { 194 return null; 195 } 196 StringBuilder sbuf = new StringBuilder(); 197 sbuf.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n"); 198 sbuf.append("<log4j:eventSet xmlns:log4j=\"http://logging.apache.org/log4j/\">\r\n"); 199 return sbuf.toString().getBytes(getCharset()); 200 } 201 202 203 /** 204 * Returns appropriate XML headers. 205 * @return a byte array containing the footer. 206 */ 207 @Override 208 public byte[] getFooter() { 209 if (!complete) { 210 return null; 211 } 212 StringBuilder sbuf = new StringBuilder(); 213 sbuf.append("</log4j:eventSet>\r\n"); 214 return sbuf.toString().getBytes(getCharset()); 215 } 216 217 List<String> getThrowableString(Throwable throwable) { 218 StringWriter sw = new StringWriter(); 219 PrintWriter pw = new PrintWriter(sw); 220 try { 221 throwable.printStackTrace(pw); 222 } catch (RuntimeException ex) { 223 // Ignore any exceptions. 224 } 225 pw.flush(); 226 LineNumberReader reader = new LineNumberReader(new StringReader(sw.toString())); 227 ArrayList<String> lines = new ArrayList<String>(); 228 try { 229 String line = reader.readLine(); 230 while (line != null) { 231 lines.add(line); 232 line = reader.readLine(); 233 } 234 } catch (IOException ex) { 235 if (ex instanceof InterruptedIOException) { 236 Thread.currentThread().interrupt(); 237 } 238 lines.add(ex.toString()); 239 } 240 return lines; 241 } 242 243 /** 244 * Create an XML Layout. 245 * @param locationInfo If "true" include the location information in the generated XML. 246 * @param properties If "true" include the thread context in the generated XML. 247 * @param complete If "true" include the XML header. 248 * @param charset The character set to use. 249 * @return An XML Layout. 250 */ 251 @PluginFactory 252 public static XMLLayout createLayout(@PluginAttr("locationInfo") String locationInfo, 253 @PluginAttr("properties") String properties, 254 @PluginAttr("complete") String complete, 255 @PluginAttr("charset") String charset) { 256 Charset c = Charset.isSupported("UTF-8") ? Charset.forName("UTF-8") : Charset.defaultCharset(); 257 if (charset != null) { 258 if (Charset.isSupported(charset)) { 259 c = Charset.forName(charset); 260 } else { 261 LOGGER.error("Charset " + charset + " is not supported for layout, using " + c.displayName()); 262 } 263 } 264 boolean info = locationInfo == null ? false : Boolean.valueOf(locationInfo); 265 boolean props = properties == null ? false : Boolean.valueOf(properties); 266 boolean comp = complete == null ? false : Boolean.valueOf(complete); 267 return new XMLLayout(info, props, comp, c); 268 } 269 }