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