Constructor Detail

• BaseObjectPool

  public BaseObjectPool()

Method Detail

• borrowObject

  public abstract T borrowObject()
                          throws java.lang.Exception

  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 with PooledObjectFactory.activateObject(org.apache.tomcat.dbcp.pool2.PooledObject<T>) and then validated with PooledObjectFactory.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 behaviour of this method when the pool has been exhausted is not strictly specified (although it may be specified by implementations).

  Specified by:

  borrowObject in interface ObjectPool<T>

  Returns:

  an instance from this pool.

  Throws:

  java.lang.IllegalStateException - after close has been called on this pool.

  java.lang.Exception - when PooledObjectFactory.makeObject() throws an exception.

  java.util.NoSuchElementException - when the pool is exhausted and cannot or will not return another instance.

• returnObject

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

  Description copied from interface: ObjectPool
  Returns an instance to the pool. By contract, obj must have been obtained using ObjectPool.borrowObject() or a related method as defined in an implementation or sub-interface.

  Specified by:

  returnObject in interface ObjectPool<T>

  Parameters:

  obj - a borrowed instance to be returned.

  Throws:

  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

• invalidateObject

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

  Description copied from interface: ObjectPool
  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.

  Specified by:

  invalidateObject in interface ObjectPool<T>

  Parameters:

  obj - a borrowed instance to be disposed.

  Throws:

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

• getNumIdle

  public int getNumIdle()

  Not supported in this base implementation.

  Specified by:

  getNumIdle in interface ObjectPool<T>

  Returns:

  a negative value.

• getNumActive

  public int getNumActive()

  Not supported in this base implementation.

  Specified by:

  getNumActive in interface ObjectPool<T>

  Returns:

  a negative value.

• clear

  public void clear()
             throws java.lang.Exception,
                    java.lang.UnsupportedOperationException

  Not supported in this base implementation.

  Specified by:

  clear in interface ObjectPool<T>

  Throws:

  java.lang.UnsupportedOperationException - if the pool does not implement this method

  java.lang.Exception - if the pool cannot be cleared

• addObject

  public void addObject()
                 throws java.lang.Exception,
                        java.lang.UnsupportedOperationException

  Not supported in this base implementation. Subclasses should override this behavior.

  Specified by:

  addObject in interface ObjectPool<T>

  Throws:

  java.lang.UnsupportedOperationException - if the pool does not implement this method

  java.lang.Exception - when PooledObjectFactory.makeObject() fails.

  java.lang.IllegalStateException - after ObjectPool.close() has been called on this pool.

• close

  public void close()

  Closes this pool, and free any resources associated with it.

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

  Implementations should silently fail if not all resources can be freed.

  This affects the behavior of isClosed and assertOpen.

  Specified by:

  close in interface java.io.Closeable

  Specified by:

  close in interface java.lang.AutoCloseable

  Specified by:

  close in interface ObjectPool<T>

• 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 java.lang.IllegalStateException

  Throws an IllegalStateException when this pool has been closed.

  Throws:

  java.lang.IllegalStateException - when this pool has been closed.

  See Also:

  isClosed()

• toStringAppendFields

  protected void toStringAppendFields(java.lang.StringBuilder builder)

  Description copied from class: BaseObject
  Used by sub-classes to include the fields defined by the sub-class in the BaseObject.toString() output.

  Overrides:

  toStringAppendFields in class BaseObject

  Parameters:

  builder - Field names and values are appended to this object