XMLLayout.java
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
// Contributors: Mathias Bogaert
package org.apache.log4j.xml;
import org.apache.log4j.Layout;
import org.apache.log4j.helpers.Transform;
import org.apache.log4j.spi.LocationInfo;
import org.apache.log4j.spi.LoggingEvent;
import java.util.Set;
import java.util.Arrays;
/**
* The output of the XMLLayout consists of a series of log4j:event elements as defined in the <a
* href="log4j.dtd">log4j.dtd</a>. It does not output a complete well-formed XML file. The output is designed to be
* included as an
* <em>external entity</em> in a separate file to form a correct XML file.
*
* <p>
* For example, if <code>abc</code> is the name of the file where the XMLLayout ouput goes, then a well-formed XML file
* would be:
*
* <pre>
* <?xml version="1.0" ?>
*
* <!DOCTYPE log4j:eventSet PUBLIC "-//APACHE//DTD LOG4J 1.2//EN" "log4j.dtd" [<!ENTITY data SYSTEM "abc">]>
*
* <log4j:eventSet version="1.2" xmlns:log4j="http://jakarta.apache.org/log4j/">
* &data;
* </log4j:eventSet>
* </pre>
*
* <p>
* This approach enforces the independence of the XMLLayout and the appender where it is embedded.
*
* <p>
* The <code>version</code> attribute helps components to correctly intrepret output generated by XMLLayout. The value
* of this attribute should be "1.1" for output generated by log4j versions prior to log4j 1.2 (final release) and "1.2"
* for relase 1.2 and later.
* <p>
* Appenders using this layout should have their encoding set to UTF-8 or UTF-16, otherwise events containing non ASCII
* characters could result in corrupted log files.
*
* @author Ceki Gülcü
* @since 0.9.0
*/
public class XMLLayout extends Layout {
private final int DEFAULT_SIZE = 256;
private final int UPPER_LIMIT = 2048;
private StringBuffer buf = new StringBuffer(DEFAULT_SIZE);
private boolean locationInfo = false;
private boolean properties = false;
/**
* The <b>LocationInfo</b> option takes a boolean value. By default, it is set to false which means there will be no
* location information output by this layout. If the the option is set to true, then the file name and line number
* of the statement at the origin of the log statement will be output.
*
* <p>
* If you are embedding this layout within an {@link org.apache.log4j.net.SMTPAppender} then make sure to set the
* <b>LocationInfo</b> option of that appender as well.
*/
public void setLocationInfo(boolean flag) {
locationInfo = flag;
}
/**
* Returns the current value of the <b>LocationInfo</b> option.
*/
public boolean getLocationInfo() {
return locationInfo;
}
/**
* Sets whether MDC key-value pairs should be output, default false.
*
* @param flag new value.
* @since 1.2.15
*/
public void setProperties(final boolean flag) {
properties = flag;
}
/**
* Gets whether MDC key-value pairs should be output.
*
* @return true if MDC key-value pairs are output.
* @since 1.2.15
*/
public boolean getProperties() {
return properties;
}
/**
* No options to activate.
*/
public void activateOptions() {
}
/**
* Formats a {@link org.apache.log4j.spi.LoggingEvent} in conformance with the log4j.dtd.
*/
public String format(final LoggingEvent event) {
// Reset working buffer. If the buffer is too large, then we need a new
// one in order to avoid the penalty of creating a large array.
if (buf.capacity() > UPPER_LIMIT) {
buf = new StringBuffer(DEFAULT_SIZE);
} else {
buf.setLength(0);
}
// We yield to the \r\n heresy.
buf.append("<log4j:event logger=\"");
buf.append(Transform.escapeTags(event.getLoggerName()));
buf.append("\" timestamp=\"");
buf.append(event.timeStamp);
buf.append("\" level=\"");
buf.append(Transform.escapeTags(String.valueOf(event.getLevel())));
buf.append("\" thread=\"");
buf.append(Transform.escapeTags(event.getThreadName()));
buf.append("\">\r\n");
buf.append("<log4j:message><![CDATA[");
// Append the rendered message. Also make sure to escape any
// existing CDATA sections.
Transform.appendEscapingCDATA(buf, event.getRenderedMessage());
buf.append("]]></log4j:message>\r\n");
String ndc = event.getNDC();
if (ndc != null) {
buf.append("<log4j:NDC><![CDATA[");
Transform.appendEscapingCDATA(buf, ndc);
buf.append("]]></log4j:NDC>\r\n");
}
String[] s = event.getThrowableStrRep();
if (s != null) {
buf.append("<log4j:throwable><![CDATA[");
for (int i = 0; i < s.length; i++) {
Transform.appendEscapingCDATA(buf, s[i]);
buf.append("\r\n");
}
buf.append("]]></log4j:throwable>\r\n");
}
if (locationInfo) {
LocationInfo locationInfo = event.getLocationInformation();
buf.append("<log4j:locationInfo class=\"");
buf.append(Transform.escapeTags(locationInfo.getClassName()));
buf.append("\" method=\"");
buf.append(Transform.escapeTags(locationInfo.getMethodName()));
buf.append("\" file=\"");
buf.append(Transform.escapeTags(locationInfo.getFileName()));
buf.append("\" line=\"");
buf.append(locationInfo.getLineNumber());
buf.append("\"/>\r\n");
}
if (properties) {
Set keySet = event.getPropertyKeySet();
if (keySet.size() > 0) {
buf.append("<log4j:properties>\r\n");
Object[] keys = keySet.toArray();
Arrays.sort(keys);
for (int i = 0; i < keys.length; i++) {
String key = keys[i].toString();
Object val = event.getMDC(key);
if (val != null) {
buf.append("<log4j:data name=\"");
buf.append(Transform.escapeTags(key));
buf.append("\" value=\"");
buf.append(Transform.escapeTags(String.valueOf(val)));
buf.append("\"/>\r\n");
}
}
buf.append("</log4j:properties>\r\n");
}
}
buf.append("</log4j:event>\r\n\r\n");
return buf.toString();
}
/**
* The XMLLayout prints and does not ignore exceptions. Hence the return value
* <code>false</code>.
*/
public boolean ignoresThrowable() {
return false;
}
}