BaseObjectPool (Apache Tomcat 7.0.109 API Documentation)

java.lang.Object
- org.apache.tomcat.dbcp.pool.BaseObjectPool<T>

Type Parameters:
T - the type of objects held in this pool

All Implemented Interfaces:

ObjectPool<T>

Direct Known Subclasses:

GenericObjectPool, SoftReferenceObjectPool, StackObjectPool
```
public abstract class BaseObjectPool<T>
extends Object
implements ObjectPool<T>
```
A simple base implementation of ObjectPool. Optional operations are implemented to either do nothing, return a value indicating it is unsupported or throw UnsupportedOperationException.

Since:

Pool 1.0

Author:

Rodney Waldhoff, Sandy McArthur

Constructor Summary

Constructors
Constructor and Description

BaseObjectPool()

Constructors
Constructor and Description
`BaseObjectPool()`

Method Summary

Methods
Modifier and Type	Method and Description
`void`	`addObject()` Not supported in this base implementation.
`protected void`	`assertOpen()` Throws an `IllegalStateException` when this pool has been closed.
`abstract T`	`borrowObject()` Obtains an instance from the pool.
`void`	`clear()` Not supported in this base implementation.
`void`	`close()` Close this pool.
`int`	`getNumActive()` Not supported in this base implementation.
`int`	`getNumIdle()` Not supported in this base implementation.
`abstract void`	`invalidateObject(T obj)` Invalidates an object from the pool.
`boolean`	`isClosed()` Has this pool instance been closed.
`abstract void`	`returnObject(T obj)` Returns an instance to the pool.
`void`	`setFactory(PoolableObjectFactory<T> factory)` Deprecated. to be removed in pool 2.0

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - BaseObjectPool
```
public BaseObjectPool()
```
- Method Detail
  - borrowObject
```
public abstract T borrowObject()
                        throws Exception
```
    Obtains an instance from the pool.
    
    Specified by:
    
    borrowObject in interface ObjectPool<T>
    
    Returns:
    an instance from the pool
    
    Throws:
    
    Exception - if an instance cannot be obtained from the pool
  - returnObject
```
public abstract void returnObject(T obj)
                           throws Exception
```
    Returns an instance to the pool.
    
    Specified by:
    
    returnObject in interface ObjectPool<T>
    
    Parameters:
    obj - instance to return to the pool
    
    Throws:
    
    Exception
  - invalidateObject
```
public abstract void invalidateObject(T obj)
                               throws Exception
```
    Invalidates an object from the pool.
    
    By contract, obj must have been obtained using borrowObject.
    
    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 interface ObjectPool<T>
    
    Parameters:
    obj - a borrowed instance to be disposed.
    
    Throws:
    
    Exception
  - getNumIdle
```
public int getNumIdle()
               throws UnsupportedOperationException
```
    Not supported in this base implementation.
    
    Specified by:
    
    getNumIdle in interface ObjectPool<T>
    
    Returns:
    a negative value.
    
    Throws:
    
    UnsupportedOperationException
  - getNumActive
```
public int getNumActive()
                 throws UnsupportedOperationException
```
    Not supported in this base implementation.
    
    Specified by:
    
    getNumActive in interface ObjectPool<T>
    
    Returns:
    a negative value.
    
    Throws:
    
    UnsupportedOperationException
  - clear
```
public void clear()
           throws Exception,
                  UnsupportedOperationException
```
    Not supported in this base implementation.
    
    Specified by:
    
    clear in interface ObjectPool<T>
    
    Throws:
    
    UnsupportedOperationException
    
    Exception
  - addObject
```
public void addObject()
               throws Exception,
                      UnsupportedOperationException
```
    Not supported in this base implementation. Always throws an UnsupportedOperationException, subclasses should override this behavior.
    
    Specified by:
    
    addObject in interface ObjectPool<T>
    
    Throws:
    
    UnsupportedOperationException
    
    Exception - when PoolableObjectFactory.makeObject() fails.
    
    IllegalStateException - after ObjectPool.close() has been called on this pool.
  - close
```
public void close()
           throws Exception
```
    Close this pool. This affects the behavior of isClosed and assertOpen.
    
    Specified by:
    
    close in interface ObjectPool<T>
    
    Throws:
    
    Exception - deprecated: implementations should silently fail if not all resources can be freed.
  - setFactory
```
@Deprecated
public void setFactory(PoolableObjectFactory<T> factory)
                throws IllegalStateException,
                       UnsupportedOperationException
```
    Deprecated. to be removed in pool 2.0
    
    Not supported in this base implementation. Always throws an UnsupportedOperationException, subclasses should override this behavior.
    
    Specified by:
    
    setFactory in interface ObjectPool<T>
    
    Parameters:
    factory - the PoolableObjectFactory
    
    Throws:
    
    UnsupportedOperationException
    
    IllegalStateException
  - isClosed
```
public final boolean isClosed()
```
    Has this pool instance been closed.
    
    Returns:
    true when this pool has been closed.
  - assertOpen
```
protected final void assertOpen()
                         throws IllegalStateException
```
    Throws an IllegalStateException when this pool has been closed.
    
    Throws:
    
    IllegalStateException - when this pool has been closed.
    See Also:
    isClosed()

Class BaseObjectPool<T>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

BaseObjectPool

Method Detail

borrowObject

returnObject

invalidateObject

getNumIdle

getNumActive

clear

addObject

close

setFactory

isClosed

assertOpen