PooledObject (Apache Tomcat 9.0.0.M9 API Documentation)

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

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and 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)` Called to inform the object that the eviction test has ended.
`boolean`	`equals(Object obj)`
`long`	`getActiveTimeMillis()` Obtain the time in milliseconds that this object last spent in the the active state (it may still be active in which case subsequent calls will return an increased value).
`long`	`getCreateTime()` Obtain the time (using the same basis as `System.currentTimeMillis()`) that this object was created.
`long`	`getIdleTimeMillis()` Obtain the time in milliseconds that this object last spend in the the idle state (it may still be idle in which case subsequent calls will return an increased value).
`long`	`getLastBorrowTime()` Obtain the time the wrapped object was last borrowed.
`long`	`getLastReturnTime()` Obtain the time the wrapped object was last returned.
`long`	`getLastUsedTime()` Return an estimate of the last time this object was used.
`T`	`getObject()` Obtain the underlying object that is wrapped by this instance of `PooledObject`.
`PooledObjectState`	`getState()` Returns the state of this object.
`int`	`hashCode()`
`void`	`invalidate()` Sets the state to `INVALID`
`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)` Is abandoned object tracking being used?
`boolean`	`startEvictionTest()` Attempt to place the pooled object in the `PooledObjectState.EVICTION` state.
`String`	`toString()` Provides a String form of the wrapper for debug purposes.
`void`	`use()` Record the current stack trace as the last time the object was used.

- Method Detail
  - getObject
```
T getObject()
```
    Obtain the underlying object that is wrapped by this instance of PooledObject.
    
    Returns:
    
    The wrapped object
  - getCreateTime
```
long getCreateTime()
```
    Obtain the time (using the same basis as System.currentTimeMillis()) that this object was created.
    
    Returns:
    
    The creation time for the wrapped object
  - getActiveTimeMillis
```
long getActiveTimeMillis()
```
    Obtain the time in milliseconds that this object last spent in the 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
  - getIdleTimeMillis
```
long getIdleTimeMillis()
```
    Obtain the time in milliseconds that this object last spend in the 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
  - getLastBorrowTime
```
long getLastBorrowTime()
```
    Obtain the time the wrapped object was last borrowed.
    
    Returns:
    
    The time the object was last borrowed
  - getLastReturnTime
```
long getLastReturnTime()
```
    Obtain the time the wrapped object was last returned.
    
    Returns:
    
    The time the object was last returned
  - getLastUsedTime
```
long getLastUsedTime()
```
    Return 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.getLastUsed() and getLastBorrowTime(); otherwise this method gives the same value as getLastBorrowTime().
    
    Returns:
    
    the last time this object was used
  - 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<PooledObject<T>>
  - equals
```
boolean equals(Object obj)
```
    Overrides:
    
    equals in class Object
  - hashCode
```
int hashCode()
```
    Overrides:
    
    hashCode in class Object
  - toString
```
String toString()
```
    Provides 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
  - startEvictionTest
```
boolean startEvictionTest()
```
    Attempt to place the pooled object in the PooledObjectState.EVICTION state.
    
    Returns:
    
    true if the object was placed in the PooledObjectState.EVICTION state otherwise false
  - endEvictionTest
```
boolean endEvictionTest(Deque<PooledObject<T>> idleQueue)
```
    Called to inform 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
  - allocate
```
boolean allocate()
```
    Allocates the object.
    
    Returns:
    
    true if the original state was IDLE
  - deallocate
```
boolean deallocate()
```
    Deallocates the object and sets it IDLE if it is currently ALLOCATED.
    
    Returns:
    
    true if the state was ALLOCATED
  - invalidate
```
void invalidate()
```
    Sets the state to INVALID
  - setLogAbandoned
```
void setLogAbandoned(boolean logAbandoned)
```
    Is abandoned object tracking being used? 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
  - use
```
void use()
```
    Record the current stack trace as the last time the object was used.
  - 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
  - getState
```
PooledObjectState getState()
```
    Returns the state of this object.
    
    Returns:
    
    state
  - markAbandoned
```
void markAbandoned()
```
    Marks the pooled object as abandoned.
  - markReturning
```
void markReturning()
```
    Marks the object as returning to the pool.

Interface PooledObject<T>

Method Summary

Method Detail

getObject

getCreateTime

getActiveTimeMillis

getIdleTimeMillis

getLastBorrowTime

getLastReturnTime

getLastUsedTime

compareTo

equals

hashCode

toString

startEvictionTest

endEvictionTest

allocate

deallocate

invalidate

setLogAbandoned

use

printStackTrace

getState

markAbandoned

markReturning