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.HashMap; 028 import java.util.List; 029 import java.util.Map; 030 031 import org.apache.logging.log4j.core.config.plugins.Plugin; 032 import org.apache.logging.log4j.core.config.plugins.PluginAttr; 033 import org.apache.logging.log4j.core.config.plugins.PluginFactory; 034 import org.apache.logging.log4j.core.helpers.Charsets; 035 import org.apache.logging.log4j.core.helpers.Transform; 036 import org.apache.logging.log4j.core.LogEvent; 037 import org.apache.logging.log4j.message.Message; 038 import org.apache.logging.log4j.message.MultiformatMessage; 039 040 041 /** 042 * The output of the XMLLayout consists of a series of log4j:event 043 * elements as defined in the <a href="log4j.dtd">log4j.dtd</a>. If configured to do so it will 044 * output a complete well-formed XML file. The output is designed to be 045 * included as an <em>external entity</em> in a separate file to form 046 * a correct XML file. 047 * <p/> 048 * <p>For example, if <code>abc</code> is the name of the file where 049 * the XMLLayout ouput goes, then a well-formed XML file would be: 050 * <p/> 051 * <pre> 052 * <?xml version="1.0" ?> 053 * 054 * <!DOCTYPE log4j:eventSet SYSTEM "log4j.dtd" [<!ENTITY data SYSTEM "abc">]> 055 * 056 * <log4j:eventSet version="1.2" xmlns:log4j="http://logging.apache.org/log4j/"> 057 * &data; 058 * </log4j:eventSet> 059 * </pre> 060 * <p/> 061 * <p>This approach enforces the independence of the XMLLayout and the 062 * appender where it is embedded. 063 * <p/> 064 * <p>The <code>version</code> attribute helps components to correctly 065 * interpret output generated by XMLLayout. The value of this 066 * attribute should be "1.1" for output generated by log4j versions 067 * prior to log4j 1.2 (final release) and "1.2" for release 1.2 and 068 * later. 069 * <p/> 070 * Appenders using this layout should have their encoding 071 * set to UTF-8 or UTF-16, otherwise events containing 072 * non ASCII characters could result in corrupted 073 * log files. 074 */ 075 @Plugin(name = "XMLLayout", type = "Core", elementType = "layout", printObject = true) 076 public class XMLLayout extends AbstractStringLayout { 077 078 private static final int DEFAULT_SIZE = 256; 079 080 private static final String[] FORMATS = new String[] {"xml"}; 081 082 private final boolean locationInfo; 083 private final boolean properties; 084 private final boolean complete; 085 086 protected XMLLayout(final boolean locationInfo, final boolean properties, final boolean complete, 087 final Charset charset) { 088 super(charset); 089 this.locationInfo = locationInfo; 090 this.properties = properties; 091 this.complete = complete; 092 } 093 094 /** 095 * Formats a {@link org.apache.logging.log4j.core.LogEvent} in conformance with the log4j.dtd. 096 * 097 * @param event The LogEvent. 098 * @return The XML representation of the LogEvent. 099 */ 100 public String toSerializable(final LogEvent event) { 101 final StringBuilder buf = new StringBuilder(DEFAULT_SIZE); 102 103 // We yield to the \r\n heresy. 104 105 buf.append("<log4j:event logger=\""); 106 String name = event.getLoggerName(); 107 if (name.length() == 0) { 108 name = "root"; 109 } 110 buf.append(Transform.escapeTags(name)); 111 buf.append("\" timestamp=\""); 112 buf.append(event.getMillis()); 113 buf.append("\" level=\""); 114 buf.append(Transform.escapeTags(String.valueOf(event.getLevel()))); 115 buf.append("\" thread=\""); 116 buf.append(Transform.escapeTags(event.getThreadName())); 117 buf.append("\">\r\n"); 118 119 final Message msg = event.getMessage(); 120 if (msg != null) { 121 boolean xmlSupported = false; 122 if (msg instanceof MultiformatMessage) { 123 final String[] formats = ((MultiformatMessage) msg).getFormats(); 124 for (final String format : formats) { 125 if (format.equalsIgnoreCase("XML")) { 126 xmlSupported = true; 127 } 128 } 129 } 130 if (xmlSupported) { 131 buf.append("<log4j:message>"); 132 buf.append(((MultiformatMessage) msg).getFormattedMessage(FORMATS)); 133 buf.append("</log4j:message>"); 134 } else { 135 buf.append("<log4j:message><![CDATA["); 136 // Append the rendered message. Also make sure to escape any 137 // existing CDATA sections. 138 Transform.appendEscapingCDATA(buf, event.getMessage().getFormattedMessage()); 139 buf.append("]]></log4j:message>\r\n"); 140 } 141 } 142 143 if (event.getContextStack().getDepth() > 0) { 144 buf.append("<log4j:NDC><![CDATA["); 145 Transform.appendEscapingCDATA(buf, event.getContextStack().toString()); 146 buf.append("]]></log4j:NDC>\r\n"); 147 } 148 149 final Throwable throwable = event.getThrown(); 150 if (throwable != null) { 151 final List<String> s = getThrowableString(throwable); 152 buf.append("<log4j:throwable><![CDATA["); 153 for (final String str : s) { 154 Transform.appendEscapingCDATA(buf, str); 155 buf.append("\r\n"); 156 } 157 buf.append("]]></log4j:throwable>\r\n"); 158 } 159 160 if (locationInfo) { 161 final StackTraceElement element = event.getSource(); 162 buf.append("<log4j:locationInfo class=\""); 163 buf.append(Transform.escapeTags(element.getClassName())); 164 buf.append("\" method=\""); 165 buf.append(Transform.escapeTags(element.getMethodName())); 166 buf.append("\" file=\""); 167 buf.append(Transform.escapeTags(element.getFileName())); 168 buf.append("\" line=\""); 169 buf.append(element.getLineNumber()); 170 buf.append("\"/>\r\n"); 171 } 172 173 if (properties && event.getContextMap().size() > 0) { 174 buf.append("<log4j:properties>\r\n"); 175 for (final Map.Entry<String, String> entry : event.getContextMap().entrySet()) { 176 buf.append("<log4j:data name=\""); 177 buf.append(Transform.escapeTags(entry.getKey())); 178 buf.append("\" value=\""); 179 buf.append(Transform.escapeTags(String.valueOf(entry.getValue()))); 180 buf.append("\"/>\r\n"); 181 } 182 buf.append("</log4j:properties>\r\n"); 183 } 184 185 buf.append("</log4j:event>\r\n\r\n"); 186 187 return buf.toString(); 188 } 189 190 /** 191 * Returns appropriate XML headers. 192 * @return a byte array containing the header. 193 */ 194 @Override 195 public byte[] getHeader() { 196 if (!complete) { 197 return null; 198 } 199 final StringBuilder sbuf = new StringBuilder(); 200 sbuf.append("<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n"); 201 sbuf.append("<log4j:eventSet xmlns:log4j=\"http://logging.apache.org/log4j/\">\r\n"); 202 return sbuf.toString().getBytes(getCharset()); 203 } 204 205 206 /** 207 * Returns appropriate XML headers. 208 * @return a byte array containing the footer. 209 */ 210 @Override 211 public byte[] getFooter() { 212 if (!complete) { 213 return null; 214 } 215 final StringBuilder sbuf = new StringBuilder(); 216 sbuf.append("</log4j:eventSet>\r\n"); 217 return sbuf.toString().getBytes(getCharset()); 218 } 219 220 /** 221 * XMLLayout's content format is specified by:<p/> 222 * Key: "dtd" Value: "log4j.dtd"<p/> 223 * Key: "version" Value: "1.2" 224 * @return Map of content format keys supporting XMLLayout 225 */ 226 public Map<String, String> getContentFormat() { 227 Map<String, String> result = new HashMap<String, String>(); 228 result.put("dtd", "log4j.dtd"); 229 result.put("version", "1.2"); 230 return result; 231 } 232 233 @Override 234 /** 235 * @return The content type. 236 */ 237 public String getContentType() { 238 return "text/xml"; 239 } 240 241 List<String> getThrowableString(final Throwable throwable) { 242 final StringWriter sw = new StringWriter(); 243 final PrintWriter pw = new PrintWriter(sw); 244 try { 245 throwable.printStackTrace(pw); 246 } catch (final RuntimeException ex) { 247 // Ignore any exceptions. 248 } 249 pw.flush(); 250 final LineNumberReader reader = new LineNumberReader(new StringReader(sw.toString())); 251 final ArrayList<String> lines = new ArrayList<String>(); 252 try { 253 String line = reader.readLine(); 254 while (line != null) { 255 lines.add(line); 256 line = reader.readLine(); 257 } 258 } catch (final IOException ex) { 259 if (ex instanceof InterruptedIOException) { 260 Thread.currentThread().interrupt(); 261 } 262 lines.add(ex.toString()); 263 } 264 return lines; 265 } 266 267 /** 268 * Create an XML Layout. 269 * @param locationInfo If "true" include the location information in the generated XML. 270 * @param properties If "true" include the thread context in the generated XML. 271 * @param complete If "true" include the XML header. 272 * @param charsetName The character set to use. 273 * @return An XML Layout. 274 */ 275 @PluginFactory 276 public static XMLLayout createLayout(@PluginAttr("locationInfo") final String locationInfo, 277 @PluginAttr("properties") final String properties, 278 @PluginAttr("complete") final String complete, 279 @PluginAttr("charset") final String charsetName) { 280 final Charset charset = Charsets.getSupportedCharset(charsetName); 281 final boolean info = locationInfo == null ? false : Boolean.valueOf(locationInfo); 282 final boolean props = properties == null ? false : Boolean.valueOf(properties); 283 final boolean comp = complete == null ? false : Boolean.valueOf(complete); 284 return new XMLLayout(info, props, comp, charset); 285 } 286 }