org.apache.commons.pool2.impl

类 SoftReferenceObjectPool<T>

java.lang.Object

org.apache.commons.pool2.BaseObject

org.apache.commons.pool2.BaseObjectPool<T>

org.apache.commons.pool2.impl.SoftReferenceObjectPool<T>

类型参数:

T - Type of element pooled in this pool.

所有已实现的接口:

java.io.Closeable, java.lang.AutoCloseable, ObjectPool<T>

public class SoftReferenceObjectPool<T>
extends BaseObjectPool<T>

A SoftReference based ObjectPool.

This class is intended to be thread-safe.

从以下版本开始:

2.0

构造器概要

构造器

构造器和说明
SoftReferenceObjectPool(PooledObjectFactory<T> factory) Create a SoftReferenceObjectPool with the specified factory.

方法概要

限定符和类型	方法和说明
void	addObject() Creates an object, and places it into the pool. addObject() is useful for "pre-loading" a pool with idle objects.
T	borrowObject() Borrows an object from the pool.
void	clear() Clears any objects sitting idle in the pool.
void	close() Closes this pool, and frees any resources associated with it.
PooledObjectFactory<T>	getFactory() Gets the PooledObjectFactory used by this pool to create and manage object instances.
int	getNumActive() Gets the number of instances currently borrowed from this pool.
int	getNumIdle() Gets an approximation not less than the of the number of idle instances in the pool.
void	invalidateObject(T obj) Invalidates an object from the pool.
void	returnObject(T obj) Returns an instance to the pool after successful validation and passivation.

从类继承的方法 org.apache.commons.pool2.BaseObjectPool

isClosed

从类继承的方法 org.apache.commons.pool2.BaseObject

toString

从类继承的方法 java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

从接口继承的方法 org.apache.commons.pool2.ObjectPool

addObjects, invalidateObject

构造器详细资料

SoftReferenceObjectPool

public SoftReferenceObjectPool(PooledObjectFactory<T> factory)

Create a SoftReferenceObjectPool with the specified factory.

参数:

factory - object factory to use.

方法详细资料

addObject

public void addObject()
               throws java.lang.Exception

Creates an object, and places it into the pool. addObject() is useful for "pre-loading" a pool with idle objects.

Before being added to the pool, the newly created instance is validated and passivated. If validation fails, the new instance is destroyed. Exceptions generated by the factory makeObject or passivate are propagated to the caller. Exceptions destroying instances are silently swallowed.

指定者:

addObject 在接口中 ObjectPool<T>

覆盖:

addObject 在类中 BaseObjectPool<T>

抛出:

java.lang.IllegalStateException - if invoked on a closed pool

java.lang.Exception - when the factory has a problem creating or passivating an object.

borrowObject

public T borrowObject()
               throws java.lang.Exception

Borrows an object from the pool. If there are no idle instances available in the pool, the configured factory's PooledObjectFactory.makeObject() method is invoked to create a new instance.

All instances are activated and validated before being returned by this method. If validation fails or an exception occurs activating or validating an idle instance, the failing instance is destroyed and another instance is retrieved from the pool, validated and activated. This process continues until either the pool is empty or an instance passes validation. If the pool is empty on activation or it does not contain any valid instances, the factory's makeObject method is used to create a new instance. If the created instance either raises an exception on activation or fails validation, NoSuchElementException is thrown. Exceptions thrown by MakeObject are propagated to the caller; but other than ThreadDeath or VirtualMachineError, exceptions generated by activation, validation or destroy methods are swallowed silently.

指定者:

borrowObject 在接口中 ObjectPool<T>

指定者:

borrowObject 在类中 BaseObjectPool<T>

返回:

a valid, activated object instance

抛出:

java.util.NoSuchElementException - if a valid object cannot be provided

java.lang.IllegalStateException - if invoked on a closed pool

java.lang.Exception - if an exception occurs creating a new instance

clear

public void clear()

Clears any objects sitting idle in the pool.

指定者:

clear 在接口中 ObjectPool<T>

覆盖:

clear 在类中 BaseObjectPool<T>

close

public void close()

Closes this pool, and frees any resources associated with it. Invokes clear() to destroy and remove instances in the pool.

Calling addObject() or borrowObject() after invoking this method on a pool will cause them to throw an IllegalStateException.

指定者:

close 在接口中 java.io.Closeable

指定者:

close 在接口中 java.lang.AutoCloseable

指定者:

close 在接口中 ObjectPool<T>

覆盖:

close 在类中 BaseObjectPool<T>

getFactory

public PooledObjectFactory<T> getFactory()

Gets the PooledObjectFactory used by this pool to create and manage object instances.

返回:

the factory

getNumActive

public int getNumActive()

Gets the number of instances currently borrowed from this pool.

指定者:

getNumActive 在接口中 ObjectPool<T>

覆盖:

getNumActive 在类中 BaseObjectPool<T>

返回:

the number of instances currently borrowed from this pool

getNumIdle

public int getNumIdle()

Gets an approximation not less than the of the number of idle instances in the pool.

指定者:

getNumIdle 在接口中 ObjectPool<T>

覆盖:

getNumIdle 在类中 BaseObjectPool<T>

返回:

estimated number of idle instances in the pool

invalidateObject

public void invalidateObject(T obj)
                      throws java.lang.Exception

Invalidates an object from the pool.

By contract, obj must have been obtained using ObjectPool.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.

指定者:

invalidateObject 在接口中 ObjectPool<T>

指定者:

invalidateObject 在类中 BaseObjectPool<T>

参数:

obj - a borrowed instance to be disposed.

抛出:

java.lang.Exception - if the instance cannot be invalidated

returnObject

public void returnObject(T obj)
                  throws java.lang.Exception

Returns an instance to the pool after successful validation and passivation. The returning instance is destroyed if any of the following are true:

• the pool is closed
• validation fails
• passivation throws an exception

Exceptions passivating or destroying instances are silently swallowed. Exceptions validating instances are propagated to the client.

指定者:

returnObject 在接口中 ObjectPool<T>

指定者:

returnObject 在类中 BaseObjectPool<T>

参数:

obj - instance to return to the pool

抛出:

java.lang.IllegalArgumentException - if obj is not currently part of this pool

java.lang.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.

java.lang.Exception - if an instance cannot be returned to the pool