org.exolab.core.database.recman
Class PMDTreeMap

java.lang.Object
  org.exolab.core.foundation.PersistentObject
      org.exolab.core.database.recman.PMDTreeMap

All Implemented Interfaces:

java.lang.Cloneable, java.io.Externalizable, PersistentCapableIfc, java.io.Serializable, TreeMapIfc

public class PMDTreeMap

extends PersistentObject

implements TreeMapIfc, java.io.Externalizable

This is an implementation of the TreeMapIfc for the PMD datastore. The implementation currently uses java.util.TreeMap but this will be changed in a subsequent release to provide a more concurrent capable container and take advantages of this database's features.

Version:

$Revision: 1.3 $ $Date: 2001/06/12 07:11:35 $

Author:

Jim Alateras

See Also:

TreeMapIfc, PersistentObject, Serialized Form

Constructor Summary

PMDTreeMap()
Default constructor simply instantiates an instance of a TreeMap

PMDTreeMap(java.util.Comparator comparator)
Construct an instance of a TreeMap with the specified comparator.

Method Summary

void	clear() Removes all mappings from this TreeMap.
java.util.Comparator	comparator() Returns the comparator used to order this map or null if this map uses natural ordering
boolean	containsKey(java.lang.Object key) Test whether a particular key is mapped to an object in the container.
boolean	containsValue(java.lang.Object value) Returns true if this map maps one or more keys to the specified value.
java.util.Collection	elements() Return an enumeration of all the elements in the map
java.lang.Object	firstKey() Returns the first (lowest) key currently in this sorted map.It throws NoSuchElementException if the element does not exist.
java.lang.Object	get(java.lang.Object key) Returns the value associated with the specified key.
boolean	isEmpty() Test is the map is empty
java.util.Set	keySet() Returns a Set view of the keys contained in this map.
java.lang.Object	lastKey() Returns the last (highest) key currently in this sorted map.It throws NoSuchElementException if the element does not exist.
java.lang.Object	put(java.lang.Object key, java.lang.Object value) Associates the specified value with the specified key in this map.
void	readExternal(java.io.ObjectInput stream)
java.lang.Object	remove(java.lang.Object key) Removes the mapping for this key from this TreeMap if present.If the key cannot be compared to other values in the map then thorw the Class- castExcpetion.
int	size() Returns the number of key-value mappings in this map.
java.util.SortedMap	sortedMap() Returns the internal TreeMap
java.util.SortedMap	tailMap(java.lang.Object key) Returns a view of the portion of this map whose keys are greater than or equal to fromKey.
void	writeExternal(java.io.ObjectOutput stream)

Methods inherited from class org.exolab.core.foundation.PersistentObject

clone, equals, getId, getMinimumObjectSize, getObjectId, getObjectVersion, getVersion, setId, setMinimumObjectSize, setObjectId, setObjectVersion, setVersion

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.exolab.core.foundation.PersistentCapableIfc

getMinimumObjectSize, getObjectId, getObjectVersion, setMinimumObjectSize

Constructor Detail

PMDTreeMap

public PMDTreeMap()

Default constructor simply instantiates an instance of a TreeMap

PMDTreeMap

public PMDTreeMap(java.util.Comparator comparator)

Construct an instance of a TreeMap with the specified comparator. The comparator is used to sort the elements in the map. If a null comparator is specified then natural order pervails.

Parameters:

comparator - used for ordering

Method Detail

size

public int size()

Returns the number of key-value mappings in this map.

Specified by:

size in interface TreeMapIfc

Returns:

number of mappings in this map.

containsKey

public boolean containsKey(java.lang.Object key)

Test whether a particular key is mapped to an object in the container. If the key cannot be compared with the jeys in the map the ClassCast- Exception is thrown. If the key is null and the map uses natural ordering or its comparator does not tolerate null raise the NullPointer- Exception

Specified by:

containsKey in interface TreeMapIfc

Parameters:

key - key whose value to find

Returns:

boolean true if the key is mapped

Throws:

java.lang.ClassCastException

java.lang.NullPointerException

containsValue

public boolean containsValue(java.lang.Object value)

Returns true if this map maps one or more keys to the specified value. More formally, returns true if and only if this map contains at least one mapping to a value v such that (value==null ? v==null : value.equals(v)). This operation will probably require time linear in the Map size for most implementations of Map.

Specified by:

containsValue in interface TreeMapIfc

Parameters:

value - test for this value

Returns:

boolean true if object is present

get

public java.lang.Object get(java.lang.Object key)

Returns the value associated with the specified key. If the key cannot be compared with the keys then the ClassCastException. If the key is null and this map uses natural ordering or its comparator does not tol- erate null keys throw the NullPointerException

Specified by:

get in interface TreeMapIfc

Parameters:

key - key whose value to find

Returns:

boolean true if the key is mapped

Throws:

java.lang.ClassCastException

java.lang.NullPointerException

comparator

public java.util.Comparator comparator()

Returns the comparator used to order this map or null if this map uses natural ordering

Specified by:

comparator in interface TreeMapIfc

Returns:

Comparator

firstKey

public java.lang.Object firstKey()

Returns the first (lowest) key currently in this sorted map.It throws NoSuchElementException if the element does not exist.

Specified by:

firstKey in interface TreeMapIfc

Returns:

Object

Throws:

NoSuchElementException

lastKey

public java.lang.Object lastKey()

Returns the last (highest) key currently in this sorted map.It throws NoSuchElementException if the element does not exist.

Specified by:

lastKey in interface TreeMapIfc

Returns:

Object

Throws:

NoSuchElementException

put

public java.lang.Object put(java.lang.Object key,
                            java.lang.Object value)

Associates the specified value with the specified key in this map. If the map previously contained a mapping for this key, the old value is replaced.

If the key cannot be compared with other keys in the map it will throw the ClassCastException. Similarly, if the key is null and the map uses natural ordering or its comparator cannot tolerate null keys throw the NullPointerException

Specified by:

put in interface TreeMapIfc

Parameters:

key - key object

value - value object

Throws:

java.lang.ClassCastException

java.lang.NullPointerException

remove

public java.lang.Object remove(java.lang.Object key)

Removes the mapping for this key from this TreeMap if present.If the key cannot be compared to other values in the map then thorw the Class- castExcpetion. Similarly, ifthe key is null and the key uses natural order or its comparator does not tolerate null keys the NullPointer- Exception is raised.

Specified by:

remove in interface TreeMapIfc

Parameters:

key - key whose value to remove

Returns:

Object remove value

Throws:

ClassCastEzception

java.lang.NullPointerException

clear

public void clear()

Removes all mappings from this TreeMap.

Specified by:

clear in interface TreeMapIfc

keySet

public java.util.Set keySet()

Returns a Set view of the keys contained in this map. The set's iterator will return the keys in ascending order. The map is backed by this TreeMap instance, so changes to this map are reflected in the Set, and vice-versa. The Set supports element removal,

Specified by:

keySet in interface TreeMapIfc

Returns:

Set view of the keys contained in this TreeMap.

isEmpty

public boolean isEmpty()

Test is the map is empty

Specified by:

isEmpty in interface TreeMapIfc

Returns:

boolean true if the map is empty and false otherwise

elements

public java.util.Collection elements()

Return an enumeration of all the elements in the map

Specified by:

elements in interface TreeMapIfc

Returns:

Enumeration

tailMap

public java.util.SortedMap tailMap(java.lang.Object key)

Returns a view of the portion of this map whose keys are greater than or equal to fromKey.

Specified by:

tailMap in interface TreeMapIfc

Returns:

a view of the portion of this map whose keys are greater than or equal to fromKey.

sortedMap

public java.util.SortedMap sortedMap()

Returns the internal TreeMap

Specified by:

sortedMap in interface TreeMapIfc

Returns:

The internal TreeMap used.

writeExternal

public void writeExternal(java.io.ObjectOutput stream)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Overrides:

writeExternal in class PersistentObject

Throws:

java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput stream)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Overrides:

readExternal in class PersistentObject

Throws:

java.io.IOException

java.lang.ClassNotFoundException