org.apache.logging.log4j.message

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:

ParameterizedMessage, Serialized Form

Constructor Summary

Constructors

Constructor and Description
ReusableParameterizedMessage() Creates a reusable message.

Method Summary

Modifier and Type	Method and Description
void	clear() Resets the object to a clean state.
<S> void	forEachParameter(ParameterConsumer<S> action, S state) Performs the given action for each parameter until all values have been processed or the action throws an exception.
void	formatTo(StringBuilder builder) Writes a text representation of this object into the specified StringBuilder, ideally without allocating temporary objects.
String	getFormat() Returns the message pattern.
String	getFormattedMessage() Returns the formatted message.
short	getParameterCount() Returns the number of parameters that was used to initialize this reusable message for the current content.
Object[]	getParameters() Returns the message parameters.
Throwable	getThrowable() Returns the Throwable that was given as the last argument, if any.
Message	memento() Returns an immutable snapshot of the current internal state of this reusable message.
Object[]	swapParameters(Object[] emptyReplacement) Returns the parameter array that was used to initialize this reusable message and replaces it with the specified array.
String	toString()

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

ReusableParameterizedMessage

public ReusableParameterizedMessage()

Creates a reusable message.

Method Detail

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:

ReusableMessage.getParameterCount()

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()

Resets the object to a clean state.