Package org.apache.commons.pool

Class BaseKeyedObjectPool<K,​V>

  • Type Parameters:
    K - the type of keys in this pool
    V - the type of objects held in this pool
    All Implemented Interfaces:
    KeyedObjectPool<K,​V>
    Direct Known Subclasses:
    GenericKeyedObjectPool, StackKeyedObjectPool
    public abstract class BaseKeyedObjectPool<K,​V>
extends java.lang.Object
implements KeyedObjectPool<K,​V>
    A simple base implementation of KeyedObjectPool. Optional operations are implemented to either do nothing, return a value indicating it is unsupported or throw UnsupportedOperationException.
    Since:
    Pool 1.0
    Version:
    $Revision: 1222396 $ $Date: 2011-12-22 14:02:25 -0500 (Thu, 22 Dec 2011) $

    • Field Summary

      Fields 
      Modifier and Type Field Description
      private boolean closed
      Whether or not the pool is close

    • Method Summary

      All Methods Instance Methods Abstract Methods Concrete Methods Deprecated Methods 
      Modifier and Type Method Description
      void addObject​(K key)
      Not supported in this base implementation.
      protected void assertOpen()
      Throws an IllegalStateException when this pool has been closed.
      abstract V borrowObject​(K key)
      Obtains an instance from this pool for the specified key.
      void clear()
      Not supported in this base implementation.
      void clear​(K key)
      Not supported in this base implementation.
      void close()
      Close this pool.
      int getNumActive()
      Not supported in this base implementation.
      int getNumActive​(K key)
      Not supported in this base implementation.
      int getNumIdle()
      Not supported in this base implementation.
      int getNumIdle​(K key)
      Not supported in this base implementation.
      abstract void invalidateObject​(K key, V obj)
      Invalidates an object from the pool.
      protected boolean isClosed()
      Has this pool instance been closed.
      abstract void returnObject​(K key, V obj)
      Return an instance to the pool.
      void setFactory​(KeyedPoolableObjectFactory<K,​V> 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

    • Field Detail

      • closed

        private volatile boolean closed
        Whether or not the pool is close

    • Constructor Detail

      • BaseKeyedObjectPool

        public BaseKeyedObjectPool()

    • Method Detail

      • borrowObject

        public abstract V borrowObject​(K key)
                        throws java.lang.Exception
        Obtains an instance from this pool for the specified key.

        Instances returned from this method will have been either newly created with makeObject or will be a previously idle object and have been activated with activateObject and then validated with validateObject.

        By contract, clients must return the borrowed object using returnObject, invalidateObject, or a related method as defined in an implementation or sub-interface, using a key that is equivalent to the one used to borrow the instance in the first place.

        The behaviour of this method when the pool has been exhausted is not strictly specified (although it may be specified by implementations). Older versions of this method would return null to indicate exhaustion, newer versions are encouraged to throw a NoSuchElementException.

        Specified by:
        borrowObject in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key used to obtain the object
        Returns:
        an instance from this pool.
        Throws:
        java.lang.IllegalStateException - after close has been called on this pool
        java.lang.Exception - when 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​(K key,
                                  V obj)
                           throws java.lang.Exception
        Return an instance to the pool. By contract, obj must have been obtained using borrowObject or a related method as defined in an implementation or sub-interface using a key that is equivalent to the one used to borrow the instance in the first place.
        Specified by:
        returnObject in interface KeyedObjectPool<K,​V>
        Parameters:
        key - the key used to obtain the object
        obj - a borrowed instance to be returned.
        Throws:
        java.lang.Exception

      • invalidateObject

        public abstract void invalidateObject​(K key,
                                      V obj)
                               throws java.lang.Exception

        Invalidates an object from the pool.

        By contract, obj must have been obtained using borrowObject using a key that is equivalent to the one used to borrow the Object in the first place.

        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 KeyedObjectPool<K,​V>
        Parameters:
        key - the key used to obtain the object
        obj - a borrowed instance to be returned.
        Throws:
        java.lang.Exception

      • addObject

        public void addObject​(K key)
               throws java.lang.Exception,
                      java.lang.UnsupportedOperationException
        Not supported in this base implementation. Always throws an UnsupportedOperationException, subclasses should override this behavior.
        Specified by:
        addObject in interface KeyedObjectPool<K,​V>
        Parameters:
        key - ignored
        Throws:
        java.lang.UnsupportedOperationException
        java.lang.Exception - when KeyedPoolableObjectFactory.makeObject(K) fails.
        java.lang.IllegalStateException - after KeyedObjectPool.close() has been called on this pool.

      • getNumIdle

        public int getNumIdle​(K key)
               throws java.lang.UnsupportedOperationException
        Not supported in this base implementation.
        Specified by:
        getNumIdle in interface KeyedObjectPool<K,​V>
        Parameters:
        key - ignored
        Returns:
        a negative value.
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation

      • getNumActive

        public int getNumActive​(K key)
                 throws java.lang.UnsupportedOperationException
        Not supported in this base implementation.
        Specified by:
        getNumActive in interface KeyedObjectPool<K,​V>
        Parameters:
        key - ignored
        Returns:
        a negative value.
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation

      • getNumIdle

        public int getNumIdle()
               throws java.lang.UnsupportedOperationException
        Not supported in this base implementation.
        Specified by:
        getNumIdle in interface KeyedObjectPool<K,​V>
        Returns:
        a negative value.
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation

      • getNumActive

        public int getNumActive()
                 throws java.lang.UnsupportedOperationException
        Not supported in this base implementation.
        Specified by:
        getNumActive in interface KeyedObjectPool<K,​V>
        Returns:
        a negative value.
        Throws:
        java.lang.UnsupportedOperationException - deprecated: when this implementation doesn't support the operation

      • clear

        public void clear()
           throws java.lang.Exception,
                  java.lang.UnsupportedOperationException
        Not supported in this base implementation.
        Specified by:
        clear in interface KeyedObjectPool<K,​V>
        Throws:
        java.lang.UnsupportedOperationException
        java.lang.Exception

      • clear

        public void clear​(K key)
           throws java.lang.Exception,
                  java.lang.UnsupportedOperationException
        Not supported in this base implementation.
        Specified by:
        clear in interface KeyedObjectPool<K,​V>
        Parameters:
        key - ignored
        Throws:
        java.lang.UnsupportedOperationException
        java.lang.Exception

      • close

        public void close()
           throws java.lang.Exception
        Close this pool. This affects the behavior of isClosed and assertOpen.
        Specified by:
        close in interface KeyedObjectPool<K,​V>
        Throws:
        java.lang.Exception

      • setFactory

        @Deprecated
public void setFactory​(KeyedPoolableObjectFactory<K,​V> factory)
                throws java.lang.IllegalStateException,
                       java.lang.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 KeyedObjectPool<K,​V>
        Parameters:
        factory - the new KeyedPoolableObjectFactory
        Throws:
        java.lang.IllegalStateException - when the factory cannot be set at this time
        java.lang.UnsupportedOperationException - when this implementation doesn't support the operation

      • isClosed

        protected final boolean isClosed()
        Has this pool instance been closed.
        Returns:
        true when this pool has been closed.
        Since:
        Pool 1.4

      • 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.
        Since:
        Pool 1.4
        See Also:
        isClosed()