Package org.apache.tomcat.dbcp.pool2

Interface PooledObject<T>

Type Parameters:

T - the type of object in the pool.

All Superinterfaces:

Comparable<PooledObject<T>>

All Known Implementing Classes:

DefaultPooledObject, PooledSoftReference

public interface PooledObject<T>
extends Comparable<PooledObject<T>>

Defines the wrapper that is used to track the additional information, such as state, for the pooled objects.

Implementations of this class are required to be thread-safe.

Since:

2.0

Method Summary

Modifier and Type	Method	Description
boolean	allocate()	Allocates the object.
int	compareTo(PooledObject<T> other)	Orders instances based on idle time - i.e. the length of time since the instance was returned to the pool.
boolean	deallocate()	Deallocates the object and sets it IDLE if it is currently ALLOCATED.
boolean	endEvictionTest(Deque<PooledObject<T>> idleQueue)	Notifies the object that the eviction test has ended.
boolean	equals(Object obj)
default Duration	getActiveDuration()	Gets the amount of time this object last spent in the active state (it may still be active in which case subsequent calls will return an increased value).
default Duration	getActiveTime()	Deprecated. Use getActiveDuration().
long	getActiveTimeMillis()	Deprecated. Use getActiveTime() which offers the best precision.
default long	getBorrowedCount()	Gets the number of times this object has been borrowed.
default Instant	getCreateInstant()	Gets the time (using the same basis as Instant.now()) that this object was created.
long	getCreateTime()	Deprecated. Use getCreateInstant() which offers the best precision.
default Duration	getFullDuration()	Gets the duration since this object was created (using Instant.now()).
default Duration	getIdleDuration()	Gets the amount of time that this object last spend in the idle state (it may still be idle in which case subsequent calls will return an increased value).
default Duration	getIdleTime()	Deprecated. Use getIdleDuration().
long	getIdleTimeMillis()	Deprecated. Use getIdleTime() which offers the best precision.
default Instant	getLastBorrowInstant()	Gets the time the wrapped object was last borrowed.
long	getLastBorrowTime()	Deprecated. Use getLastBorrowInstant() which offers the best precision.
default Instant	getLastReturnInstant()	Gets the time the wrapped object was last borrowed.
long	getLastReturnTime()	Deprecated. Use getLastReturnInstant() which offers the best precision.
default Instant	getLastUsedInstant()	Gets an estimate of the last time this object was used.
long	getLastUsedTime()	Deprecated. Use getLastUsedInstant() which offers the best precision.
T	getObject()	Gets the underlying object that is wrapped by this instance of PooledObject.
PooledObjectState	getState()	Gets the state of this object.
int	hashCode()
void	invalidate()	Sets the state to INVALID.
static boolean	isNull(PooledObject<?> pooledObject)	Tests whether the given PooledObject is null or contains a null.
void	markAbandoned()	Marks the pooled object as abandoned.
void	markReturning()	Marks the object as returning to the pool.
void	printStackTrace(PrintWriter writer)	Prints the stack trace of the code that borrowed this pooled object and the stack trace of the last code to use this object (if available) to the supplied writer.
void	setLogAbandoned(boolean logAbandoned)	Sets whether to use abandoned object tracking.
default void	setRequireFullStackTrace(boolean requireFullStackTrace)	Sets the stack trace generation strategy based on whether or not fully detailed stack traces are required.
boolean	startEvictionTest()	Attempts to place the pooled object in the PooledObjectState.EVICTION state.
String	toString()	Gets a String form of the wrapper for debug purposes.
void	use()	Records the current stack trace as the last time the object was used.

Method Details

isNull

static boolean isNull(PooledObject<?> pooledObject)

Tests whether the given PooledObject is null or contains a null.

Parameters:

pooledObject - the PooledObject to test.

Returns:

whether the given PooledObject is null or contains a null.

Since:

2.12.0

allocate

boolean allocate()

Allocates the object.

Returns:

true if the original state was IDLE

compareTo

int compareTo(PooledObject<T> other)

Orders instances based on idle time - i.e. the length of time since the instance was returned to the pool. Used by the GKOP idle object evictor.

Note: This class has a natural ordering that is inconsistent with equals if distinct objects have the same identity hash code.

Specified by:

compareTo in interface Comparable<T>

deallocate

boolean deallocate()

Deallocates the object and sets it IDLE if it is currently ALLOCATED.

Returns:

true if the state was ALLOCATED.

endEvictionTest

boolean endEvictionTest(Deque<PooledObject<T>> idleQueue)

Notifies the object that the eviction test has ended.

Parameters:

idleQueue - The queue of idle objects to which the object should be returned.

Returns:

Currently not used.

equals

boolean equals(Object obj)

Overrides:

equals in class Object

getActiveDuration

default Duration getActiveDuration()

Gets the amount of time this object last spent in the active state (it may still be active in which case subsequent calls will return an increased value).

Returns:

The duration last spent in the active state.

Since:

2.11.0

getActiveTime

@Deprecated
default Duration getActiveTime()

Deprecated.

Use getActiveDuration().

Gets the amount of time this object last spent in the active state (it may still be active in which case subsequent calls will return an increased value).

Returns:

The duration last spent in the active state.

Since:

2.10.0

getActiveTimeMillis

@Deprecated
long getActiveTimeMillis()

Deprecated.

Use getActiveTime() which offers the best precision.

Gets the amount of time in milliseconds this object last spent in the active state (it may still be active in which case subsequent calls will return an increased value).

Returns:

The time in milliseconds last spent in the active state.

getBorrowedCount

default long getBorrowedCount()

Gets the number of times this object has been borrowed.

Returns:

-1 by default for implementations prior to release 2.7.0.

Since:

2.7.0

getCreateInstant

default Instant getCreateInstant()

Gets the time (using the same basis as Instant.now()) that this object was created.

Returns:

The creation time for the wrapped object.

Since:

2.11.0

getCreateTime

@Deprecated
long getCreateTime()

Deprecated.

Use getCreateInstant() which offers the best precision.

Gets the time (using the same basis as Clock.instant()) that this object was created.

Returns:

The creation time for the wrapped object.

getFullDuration

default Duration getFullDuration()

Gets the duration since this object was created (using Instant.now()).

Returns:

The duration since this object was created.

Since:

2.12.0

getIdleDuration

default Duration getIdleDuration()

Gets the amount of time that this object last spend in the idle state (it may still be idle in which case subsequent calls will return an increased value).

Returns:

The amount of time in last spent in the idle state.

Since:

2.11.0

getIdleTime

@Deprecated
default Duration getIdleTime()

Deprecated.

Use getIdleDuration().

Gets the amount of time that this object last spend in the idle state (it may still be idle in which case subsequent calls will return an increased value).

Returns:

The amount of time in last spent in the idle state.

Since:

2.10.0

getIdleTimeMillis

@Deprecated
long getIdleTimeMillis()

Deprecated.

Use getIdleTime() which offers the best precision.

Gets the amount of time in milliseconds that this object last spend in the idle state (it may still be idle in which case subsequent calls will return an increased value).

Returns:

The time in milliseconds last spent in the idle state.

getLastBorrowInstant

default Instant getLastBorrowInstant()

Gets the time the wrapped object was last borrowed.

Returns:

The time the object was last borrowed.

Since:

2.11.0

getLastBorrowTime

@Deprecated
long getLastBorrowTime()

Deprecated.

Use getLastBorrowInstant() which offers the best precision.

Gets the time the wrapped object was last borrowed.

Returns:

The time the object was last borrowed.

getLastReturnInstant

default Instant getLastReturnInstant()

Gets the time the wrapped object was last borrowed.

Returns:

The time the object was last borrowed.

Since:

2.11.0

getLastReturnTime

@Deprecated
long getLastReturnTime()

Deprecated.

Use getLastReturnInstant() which offers the best precision.

Gets the time the wrapped object was last returned.

Returns:

The time the object was last returned.

getLastUsedInstant

default Instant getLastUsedInstant()

Gets an estimate of the last time this object was used. If the class of the pooled object implements TrackedUse, what is returned is the maximum of TrackedUse.getLastUsedInstant() and getLastBorrowTime(); otherwise this method gives the same value as getLastBorrowTime().

Returns:

the last time this object was used

Since:

2.11.0

getLastUsedTime

@Deprecated
long getLastUsedTime()

Deprecated.

Use getLastUsedInstant() which offers the best precision.

Gets an estimate of the last time this object was used. If the class of the pooled object implements TrackedUse, what is returned is the maximum of TrackedUse.getLastUsedInstant() and getLastBorrowTime(); otherwise this method gives the same value as getLastBorrowTime().

Returns:

the last time this object was used.

getObject

T getObject()

Gets the underlying object that is wrapped by this instance of PooledObject.

Returns:

The wrapped object.

getState

PooledObjectState getState()

Gets the state of this object.

Returns:

state

hashCode

int hashCode()

Overrides:

hashCode in class Object

invalidate

void invalidate()

Sets the state to INVALID.

markAbandoned

void markAbandoned()

Marks the pooled object as abandoned.

markReturning

void markReturning()

Marks the object as returning to the pool.

printStackTrace

void printStackTrace(PrintWriter writer)

Prints the stack trace of the code that borrowed this pooled object and the stack trace of the last code to use this object (if available) to the supplied writer.

Parameters:

writer - The destination for the debug output.

setLogAbandoned

void setLogAbandoned(boolean logAbandoned)

Sets whether to use abandoned object tracking. If this is true the implementation will need to record the stack trace of the last caller to borrow this object.

Parameters:

logAbandoned - The new configuration setting for abandoned object tracking.

setRequireFullStackTrace

default void setRequireFullStackTrace(boolean requireFullStackTrace)

Sets the stack trace generation strategy based on whether or not fully detailed stack traces are required. When set to false, abandoned logs may only include caller class information rather than method names, line numbers, and other normal metadata available in a full stack trace.

Parameters:

requireFullStackTrace - the new configuration setting for abandoned object logging.

Since:

2.7.0

startEvictionTest

boolean startEvictionTest()

Attempts to place the pooled object in the PooledObjectState.EVICTION state.

Returns:

true if the object was placed in the PooledObjectState.EVICTION state otherwise false.

toString

String toString()

Gets a String form of the wrapper for debug purposes. The format is not fixed and may change at any time.

Overrides:

toString in class Object

use

void use()

Records the current stack trace as the last time the object was used.