Package org.apache.logging.log4j.core.layout

Class AbstractLayout<T extends Serializable>

java.lang.Object
org.apache.logging.log4j.core.layout.AbstractLayout<T>
Type Parameters:
T - The Class that the Layout will format the LogEvent into.
All Implemented Interfaces:
Layout<T>, Encoder<LogEvent>
Direct Known Subclasses:
AbstractStringLayout, MessageLayout, SerializedLayout
public abstract class AbstractLayout<T extends Serializable> extends Object implements Layout<T>
Abstract base class for Layouts.

  • Field Details

    • LOGGER

      protected static final Logger LOGGER
      Allow subclasses access to the status logger without creating another instance.

    • configuration

      protected final Configuration configuration
      The current Configuration.

    • eventCount

      protected long eventCount
      The number of events successfully processed by this layout.

  • Constructor Details

    • AbstractLayout

      @Deprecated public AbstractLayout(byte[] header, byte[] footer)
      Deprecated.
      Use AbstractLayout(Configuration, byte[], byte[])
      Constructs a layout with an optional header and footer.
      Parameters:
      header - The header to include when the stream is opened. May be null.
      footer - The footer to add when the stream is closed. May be null.

    • AbstractLayout

      public AbstractLayout(Configuration configuration, byte[] header, byte[] footer)
      Constructs a layout with an optional header and footer.
      Parameters:
      configuration - The configuration. May be null.
      header - The header to include when the stream is opened. May be null.
      footer - The footer to add when the stream is closed. May be null.

  • Method Details

    • getConfiguration

      public Configuration getConfiguration()

    • getContentFormat

      public Map<String,String> getContentFormat()
      Description copied from interface: Layout
      Returns a description of the content format.
      Specified by:
      getContentFormat in interface Layout<T extends Serializable>
      Returns:
      a Map of key/value pairs describing the Layout-specific content format, or an empty Map if no content format descriptors are specified.

    • getFooter

      public byte[] getFooter()
      Returns the footer, if one is available.
      Specified by:
      getFooter in interface Layout<T extends Serializable>
      Returns:
      A byte array containing the footer.

    • getHeader

      public byte[] getHeader()
      Returns the header, if one is available.
      Specified by:
      getHeader in interface Layout<T extends Serializable>
      Returns:
      A byte array containing the header.

    • markEvent

      protected void markEvent()

    • encode

      public void encode(LogEvent event, ByteBufferDestination destination)
      Encodes the specified source LogEvent to some binary representation and writes the result to the specified destination.

      The default implementation of this method delegates to the Layout.toByteArray(LogEvent) method which allocates temporary objects.

      Subclasses can override this method to provide a garbage-free implementation. For text-based layouts, AbstractStringLayout provides various convenience methods to help with this: 

       @Plugin(name = "MyLayout", category = Node.CATEGORY, elementType = Layout.ELEMENT_TYPE, printObject = true)
 public final class MyLayout extends AbstractStringLayout {
     @Override
     public void encode(LogEvent event, ByteBufferDestination destination) {
         StringBuilder text = getStringBuilder();
         convertLogEventToText(event, text);
         getStringBuilderEncoder().encode(text, destination);
     }

     private void convertLogEventToText(LogEvent event, StringBuilder destination) {
         ... // append a text representation of the log event to the StringBuilder
     }
 }
      Specified by:
      encode in interface Encoder<T extends Serializable>
      Parameters:
      event - the LogEvent to encode.
      destination - holds the ByteBuffer to write into.
      See Also: