org.apache.logging.log4j.message

Class ReusableSimpleMessage

java.lang.Object

org.apache.logging.log4j.message.ReusableSimpleMessage

All Implemented Interfaces:

Serializable, CharSequence, Message, ParameterVisitable, ReusableMessage, StringBuilderFormattable

public class ReusableSimpleMessage
extends Object
implements ReusableMessage, CharSequence, ParameterVisitable

Mutable Message wrapper around a String message.

Since:

2.6

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ReusableSimpleMessage()

Method Summary

Modifier and Type	Method and Description
char	charAt(int index)
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 buffer) Writes a text representation of this object into the specified StringBuilder, ideally without allocating temporary objects.
String	getFormat() Gets the format portion of the Message.
String	getFormattedMessage() Gets the Message formatted as a String.
short	getParameterCount() This message does not have any parameters so this method always returns zero.
Object[]	getParameters() Gets parameter values, if any.
Throwable	getThrowable() Gets the throwable, if any.
int	length()
Message	memento() Returns an immutable snapshot of the current internal state of this reusable message.
void	set(CharSequence charSequence)
void	set(String message)
CharSequence	subSequence(int start, int end)
Object[]	swapParameters(Object[] emptyReplacement) This message does not have any parameters, so this method returns the specified array.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.CharSequence

chars, codePoints, toString

Constructor Detail

ReusableSimpleMessage

public ReusableSimpleMessage()

Method Detail

set

public void set(String message)

set

public void set(CharSequence charSequence)

getFormattedMessage

public String getFormattedMessage()

Description copied from interface: Message

Gets the Message formatted as a String. Each Message implementation determines the appropriate way to format the data encapsulated in the Message. Messages that provide more than one way of formatting the Message will implement MultiformatMessage.

When configured to log asynchronously, this method is called before the Message is queued, unless this message implements ReusableMessage or is annotated with AsynchronouslyFormattable. This gives the Message implementation class a chance to create a formatted message String with the current value of any mutable objects. The intention is that the Message implementation caches this formatted message and returns it on subsequent calls. (See LOG4J2-763.)

When logging synchronously, this method will not be called for Messages that implement the StringBuilderFormattable interface: instead, the formatTo(StringBuilder) method will be called so the Message can format its contents without creating intermediate String objects.

Specified by:

getFormattedMessage in interface Message

Returns:

The message String.

getFormat

public String getFormat()

Description copied from interface: Message

Gets the format portion of the Message.

Specified by:

getFormat in interface Message

Returns:

The message format. Some implementations, such as ParameterizedMessage, will use this as the message "pattern". Other Messages may simply return an empty String. TODO Do all messages have a format? What syntax? Using a Formatter object could be cleaner. (RG) In SimpleMessage the format is identical to the formatted message. In ParameterizedMessage and StructuredDataMessage it is not. It is up to the Message implementer to determine what this method will return. A Formatter is inappropriate as this is very specific to the Message implementation so it isn't clear to me how having a Formatter separate from the Message would be cleaner.

getParameters

public Object[] getParameters()

Description copied from interface: Message

Gets parameter values, if any.

Specified by:

getParameters in interface Message

Returns:

An array of parameter values or null.

getThrowable

public Throwable getThrowable()

Description copied from interface: Message

Gets the throwable, if any.

Specified by:

getThrowable in interface Message

Returns:

the throwable or null.

formatTo

public void formatTo(StringBuilder buffer)

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:

buffer - the StringBuilder to write into

swapParameters

public Object[] swapParameters(Object[] emptyReplacement)

This message does not have any parameters, so this method returns the specified array.

Specified by:

swapParameters in interface ReusableMessage

Parameters:

emptyReplacement - the parameter array to return

Returns:

the specified array

See Also:

ReusableMessage.getParameterCount()

getParameterCount

public short getParameterCount()

This message does not have any parameters so this method always returns zero.

Specified by:

getParameterCount in interface ReusableMessage

Returns:

0 (zero)

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

length

public int length()

Specified by:

length in interface CharSequence

charAt

public char charAt(int index)

Specified by:

charAt in interface CharSequence

subSequence

public CharSequence subSequence(int start,
                                int end)

Specified by:

subSequence in interface CharSequence

clear

public void clear()

Resets the object to a clean state.