Package org.apache.commons.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 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.