Class BaseObjectPool<T>
- Type Parameters:
T
- Type of element pooled in this pool.
- All Implemented Interfaces:
Closeable
,AutoCloseable
,ObjectPool<T>
- Direct Known Subclasses:
SoftReferenceObjectPool
ObjectPool
.
Optional operations are implemented to either do nothing, return a value
indicating it is unsupported or throw UnsupportedOperationException
.
This class is intended to be thread-safe.
- Since:
- 2.0
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Constructor Summary
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Method Summary
Modifier and TypeMethodDescriptionvoid
Not supported in this base implementation.void
addObjects
(int count) CallsObjectPool.addObject()
count
number of times.protected final void
Throws anIllegalStateException
when this pool has been closed.abstract T
Obtains an instance from this pool.void
clear()
Not supported in this base implementation.void
close()
Closes this pool, and free any resources associated with it.int
Not supported in this base implementation.int
Not supported in this base implementation.abstract void
invalidateObject
(T obj) Invalidates an object from the pool.final boolean
isClosed()
Has this pool instance been closed.abstract void
returnObject
(T obj) Returns an instance to the pool.protected void
toStringAppendFields
(StringBuilder builder) Used by sub-classes to include the fields defined by the sub-class in theBaseObject.toString()
output.Methods inherited from class org.apache.tomcat.dbcp.pool2.BaseObject
toString
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.apache.tomcat.dbcp.pool2.ObjectPool
invalidateObject
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Constructor Details
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BaseObjectPool
public BaseObjectPool()
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Method Details
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borrowObject
Description copied from interface:ObjectPool
Obtains an instance from this pool.Instances returned from this method will have been either newly created with
PooledObjectFactory.makeObject()
or will be a previously idle object and have been activated withPooledObjectFactory.activateObject(org.apache.tomcat.dbcp.pool2.PooledObject<T>)
and then validated withPooledObjectFactory.validateObject(org.apache.tomcat.dbcp.pool2.PooledObject<T>)
.By contract, clients must return the borrowed instance using
ObjectPool.returnObject(T)
,ObjectPool.invalidateObject(T)
, or a related method as defined in an implementation or sub-interface.The behavior of this method when the pool has been exhausted is not strictly specified (although it may be specified by implementations).
- Specified by:
borrowObject
in interfaceObjectPool<T>
- Returns:
- an instance from this pool.
- Throws:
IllegalStateException
- afterclose
has been called on this pool.Exception
- whenPooledObjectFactory.makeObject()
throws an exception.NoSuchElementException
- when the pool is exhausted and cannot or will not return another instance.
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returnObject
Description copied from interface:ObjectPool
Returns an instance to the pool. By contract,obj
must have been obtained usingObjectPool.borrowObject()
or a related method as defined in an implementation or sub-interface.- Specified by:
returnObject
in interfaceObjectPool<T>
- Parameters:
obj
- aborrowed
instance to be returned.- Throws:
IllegalStateException
- if an attempt is made to return an object to the pool that is in any state other than allocated (i.e. borrowed). Attempting to return an object more than once or attempting to return an object that was never borrowed from the pool will trigger this exception.Exception
- if an instance cannot be returned to the pool
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invalidateObject
Description copied from interface:ObjectPool
Invalidates an object from the pool.By contract,
obj
must have been obtained usingObjectPool.borrowObject()
or a related method as defined in an implementation or sub-interface.This method should be used when an object that has been borrowed is determined (due to an exception or other problem) to be invalid.
- Specified by:
invalidateObject
in interfaceObjectPool<T>
- Parameters:
obj
- aborrowed
instance to be disposed.- Throws:
Exception
- if the instance cannot be invalidated
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getNumIdle
public int getNumIdle()Not supported in this base implementation.- Specified by:
getNumIdle
in interfaceObjectPool<T>
- Returns:
- a negative value.
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getNumActive
public int getNumActive()Not supported in this base implementation.- Specified by:
getNumActive
in interfaceObjectPool<T>
- Returns:
- a negative value.
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clear
Not supported in this base implementation.- Specified by:
clear
in interfaceObjectPool<T>
- Throws:
UnsupportedOperationException
- if the pool does not implement this methodException
- if the pool cannot be cleared
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addObject
Not supported in this base implementation. Subclasses should override this behavior.- Specified by:
addObject
in interfaceObjectPool<T>
- Throws:
UnsupportedOperationException
- if the pool does not implement this methodException
- whenPooledObjectFactory.makeObject()
fails.IllegalStateException
- afterObjectPool.close()
has been called on this pool.
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addObjects
CallsObjectPool.addObject()
count
number of times.- Specified by:
addObjects
in interfaceObjectPool<T>
- Parameters:
count
- the number of idle objects to add.- Throws:
Exception
- whenObjectPool.addObject()
fails.- Since:
- 2.8.0
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close
public void close()Closes this pool, and free any resources associated with it.Calling
ObjectPool.addObject()
orObjectPool.borrowObject()
after invoking this method on a pool will cause them to throw anIllegalStateException
.Implementations should silently fail if not all resources can be freed.
This affects the behavior of
isClosed
andassertOpen
.- Specified by:
close
in interfaceAutoCloseable
- Specified by:
close
in interfaceCloseable
- Specified by:
close
in interfaceObjectPool<T>
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isClosed
public final boolean isClosed()Has this pool instance been closed.- Returns:
true
when this pool has been closed.
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assertOpen
Throws anIllegalStateException
when this pool has been closed.- Throws:
IllegalStateException
- when this pool has been closed.- See Also:
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toStringAppendFields
Description copied from class:BaseObject
Used by sub-classes to include the fields defined by the sub-class in theBaseObject.toString()
output.- Overrides:
toStringAppendFields
in classBaseObject
- Parameters:
builder
- Field names and values are appended to this object
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