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XMLLayout.javaAPI DocApache log4j 1.2.157137Sat Aug 25 00:09:42 BST 2007org.apache.log4j.xml

XMLLayout

public class XMLLayout extends Layout
The output of the XMLLayout consists of a series of log4j:event elements as defined in the log4j.dtd. It does not output a complete well-formed XML file. The output is designed to be included as an external entity in a separate file to form a correct XML file.

For example, if abc is the name of the file where the XMLLayout ouput goes, then a well-formed XML file would be: 

<?xml version="1.0" ?>

<!DOCTYPE log4j:eventSet SYSTEM "log4j.dtd" [<!ENTITY data SYSTEM "abc">]>

<log4j:eventSet version="1.2" xmlns:log4j="http://jakarta.apache.org/log4j/">
  &data;
</log4j:eventSet>

This approach enforces the independence of the XMLLayout and the appender where it is embedded.

The version 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. 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

Fields Summary
private final int
DEFAULT_SIZE
private final int
UPPER_LIMIT
private StringBuffer
buf
private boolean
locationInfo
private boolean
properties
Constructors Summary
Methods Summary
public voidactivateOptions()
No options to activate.
public java.lang.Stringformat(org.apache.log4j.spi.LoggingEvent event)
Formats a {@link org.apache.log4j.spi.LoggingEvent} in conformance with the log4j.dtd.


    // 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();
public booleangetLocationInfo()
Returns the current value of the LocationInfo option.

    return locationInfo;
public booleangetProperties()
Gets whether MDC key-value pairs should be output.

return
true if MDC key-value pairs are output.

      return properties;
public booleanignoresThrowable()
The XMLLayout prints and does not ignore exceptions. Hence the return value false.

    return false;
public voidsetLocationInfo(boolean flag)
The LocationInfo 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.

If you are embedding this layout within an {@link org.apache.log4j.net.SMTPAppender} then make sure to set the LocationInfo option of that appender as well.

 
                                                                                
      
    locationInfo = flag;
public voidsetProperties(boolean flag)
Sets whether MDC key-value pairs should be output, default false.

param
flag new value.

      properties = flag;