org.apache.logging.log4j.message
Interfaces 
LoggerNameAwareMessage
Message
MessageFactory
MultiformatMessage
TimestampMessage
Classes 
AbstractMessageFactory
FormattedMessage
FormattedMessageFactory
LocalizedMessage
LocalizedMessageFactory
MapMessage
MessageFormatMessage
MessageFormatMessageFactory
ObjectMessage
ParameterizedMessage
ParameterizedMessageFactory
SimpleMessage
StringFormattedMessage
StringFormatterMessageFactory
StructuredDataId
StructuredDataMessage
ThreadDumpMessage
Enums 
MapMessage.MapFormat
StructuredDataMessage.Format