Class ReusableParameterizedMessage

java.lang.Object
org.apache.logging.log4j.message.ReusableParameterizedMessage
All Implemented Interfaces:
Serializable, Message, ParameterVisitable, ReusableMessage, StringBuilderFormattable

public class ReusableParameterizedMessage extends Object implements ReusableMessage, ParameterVisitable
Reusable parameterized message. This message is mutable and is not safe to be accessed or modified by multiple threads concurrently.
Since:
2.6
See Also:
  • Constructor Details

    • ReusableParameterizedMessage

      public ReusableParameterizedMessage()
      Creates a reusable message.
  • Method Details

    • swapParameters

      public Object[] swapParameters(Object[] emptyReplacement)
      Description copied from interface: ReusableMessage
      Returns the parameter array that was used to initialize this reusable message and replaces it with the specified array. The returned parameter array will no longer be modified by this reusable message. The specified array is now "owned" by this reusable message and can be modified if necessary for the next log event.

      ReusableMessages that have no parameters return the specified array.

      This method is used by asynchronous loggers to pass the parameter array to a background thread without allocating new objects. The actual number of parameters in the returned array can be determined with ReusableMessage.getParameterCount().

      Specified by:
      swapParameters in interface ReusableMessage
      Parameters:
      emptyReplacement - the parameter array that can be used for subsequent uses of this reusable message. This replacement array must have at least 10 elements (the number of varargs supported by the Logger API).
      Returns:
      the parameter array for the current message content. This may be a vararg array of any length, or it may be a reusable array of 10 elements used to hold the unrolled vararg parameters.
      See Also:
    • getParameterCount

      public short getParameterCount()
      Description copied from interface: ReusableMessage
      Returns the number of parameters that was used to initialize this reusable message for the current content.

      The parameter array returned by ReusableMessage.swapParameters(Object[]) may be larger than the actual number of parameters. Callers should use this method to determine how many elements the array contains.

      Specified by:
      getParameterCount in interface ReusableMessage
      Returns:
      the current number of parameters
    • forEachParameter

      public <S> void forEachParameter(ParameterConsumer<S> action, S state)
      Description copied from interface: ParameterVisitable
      Performs the given action for each parameter until all values have been processed or the action throws an exception.

      The second parameter lets callers pass in a stateful object to be modified with the key-value pairs, so the TriConsumer implementation itself can be stateless and potentially reusable.

      Specified by:
      forEachParameter in interface ParameterVisitable
      Type Parameters:
      S - type of the third parameter
      Parameters:
      action - The action to be performed for each key-value pair in this collection
      state - the object to be passed as the third parameter to each invocation on the specified ParameterConsumer.
    • memento

      public Message memento()
      Description copied from interface: ReusableMessage
      Returns an immutable snapshot of the current internal state of this reusable message. The returned snapshot will not be affected by subsequent modifications of this reusable message.
      Specified by:
      memento in interface ReusableMessage
      Returns:
      an immutable snapshot of this message
    • getFormat

      public String getFormat()
      Returns the message pattern.
      Specified by:
      getFormat in interface Message
      Returns:
      the message pattern.
    • getParameters

      public Object[] getParameters()
      Returns the message parameters.
      Specified by:
      getParameters in interface Message
      Returns:
      the message parameters.
    • getThrowable

      public Throwable getThrowable()
      Returns the Throwable that was given as the last argument, if any. It will not survive serialization. The Throwable exists as part of the message primarily so that it can be extracted from the end of the list of parameters and then be added to the LogEvent. As such, the Throwable in the event should not be used once the LogEvent has been constructed.
      Specified by:
      getThrowable in interface Message
      Returns:
      the Throwable, if any.
    • getFormattedMessage

      public String getFormattedMessage()
      Returns the formatted message.
      Specified by:
      getFormattedMessage in interface Message
      Returns:
      the formatted message.
    • formatTo

      public void formatTo(StringBuilder builder)
      Description copied from interface: StringBuilderFormattable
      Writes a text representation of this object into the specified StringBuilder, ideally without allocating temporary objects.
      Specified by:
      formatTo in interface StringBuilderFormattable
      Parameters:
      builder - the StringBuilder to write into
    • toString

      public String toString()
      Overrides:
      toString in class Object
    • clear

      public void clear()