org.ws4d.java.structures

Class LockedStructure

java.lang.Object

org.ws4d.java.structures.DataStructure

org.ws4d.java.structures.LockedStructure

All Implemented Interfaces:

Lockable

public class LockedStructure
extends DataStructure
implements Lockable

Class encapsulates data structure, method invocations are synchronized by a Lockable object.

Constructor Summary

Constructors

Constructor and Description
LockedStructure(DataStructure data) Constructor.
LockedStructure(DataStructure data, Lockable lock) Constructor.

Method Summary

Modifier and Type	Method and Description
boolean	add(java.lang.Object obj) Adds a new object to this data structure.
boolean	addAll(DataStructure data) Adds all objects contained within data to this instance.
void	clear() Clears this data structure by removing all content from it.
boolean	contains(java.lang.Object obj) Checks whether obj (or another instance equal to obj in terms of java.lang.Object.equals(Object) ) is already present within this data structure instance and returns true only if this is the case.
boolean	containsAll(DataStructure data) Checks whether all items within data are present within this data structure instance and returns true only if this is the case.
boolean	equals(java.lang.Object o)
void	exclusiveLock() Acquires an exclusive lock.
int	hashCode()
boolean	isEmpty() Checks whether this instance is empty or not.
Iterator	iterator() Manual synchronization of iterator necessary.
boolean	releaseExclusiveLock() Releases an exclusive lock of the current thread.
void	releaseSharedLock() Releases a shared lock of the current thread.
boolean	remove(java.lang.Object obj) Removes obj from this data structure.
void	sharedLock() Acquires a shared lock.
int	size() Returns the current size of the data structure.
java.lang.Object[]	toArray() Returns an array containing all items stored within this data structure.
java.lang.Object[]	toArray(java.lang.Object[] object) Stores all contained items into the passed-in array objects.
java.lang.String	toString()
boolean	tryExclusiveLock() Try to get an exclusive lock immediately.
boolean	trySharedLock() Tries to get a shared lock immediately.

Methods inherited from class org.ws4d.java.structures.DataStructure

getClassShortName

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Constructor Detail

LockedStructure

public LockedStructure(DataStructure data,
                       Lockable lock)

Constructor.

Parameters:

data - data structure which will be encapsulated by this.

lock - Lock for access synchronization.

LockedStructure

public LockedStructure(DataStructure data)

Constructor.

Parameters:

data - data structure which will be encapsulated by this.

Method Detail

sharedLock

public void sharedLock()

Description copied from interface: Lockable

Acquires a shared lock. If the lock cannot be allocated immediately, the thread is blocked until allocation is possible.

Specified by:

sharedLock in interface Lockable

exclusiveLock

public void exclusiveLock()

Description copied from interface: Lockable

Acquires an exclusive lock. If the lock cannot be allocated immediately, the thread is blocked until allocation is possible.

Specified by:

exclusiveLock in interface Lockable

releaseSharedLock

public void releaseSharedLock()

Description copied from interface: Lockable

Releases a shared lock of the current thread.

Specified by:

releaseSharedLock in interface Lockable

releaseExclusiveLock

public boolean releaseExclusiveLock()

Description copied from interface: Lockable

Releases an exclusive lock of the current thread.

Specified by:

releaseExclusiveLock in interface Lockable

Returns:

true = if last exclusive lock of this thread is released.

tryExclusiveLock

public boolean tryExclusiveLock()

Description copied from interface: Lockable

Try to get an exclusive lock immediately.

Specified by:

tryExclusiveLock in interface Lockable

Returns:

true if the lock has been allocated, false otherwise

trySharedLock

public boolean trySharedLock()

Description copied from interface: Lockable

Tries to get a shared lock immediately.

Specified by:

trySharedLock in interface Lockable

Returns:

true if the lock has been allocated, false otherwise

iterator

public Iterator iterator()

Manual synchronization of iterator necessary.

Specified by:

iterator in class DataStructure

Returns:

an iterator over all stored objects

size

public int size()

Description copied from class: DataStructure

Returns the current size of the data structure.

Specified by:

size in class DataStructure

Returns:

the size of this data structure

contains

public boolean contains(java.lang.Object obj)

Description copied from class: DataStructure

Checks whether obj (or another instance equal to obj in terms of java.lang.Object.equals(Object) ) is already present within this data structure instance and returns true only if this is the case.

Overrides:

contains in class DataStructure

Parameters:

obj - the object to check the presence of

Returns:

true if obj is contained by this instance, false if not

remove

public boolean remove(java.lang.Object obj)

Description copied from class: DataStructure

Removes obj from this data structure. Returns true if obj was actually present and thus it was really removed (i.e. this instance was modified by the method call).

Overrides:

remove in class DataStructure

Parameters:

obj - the object to remove

Returns:

true only if obj was actually removed

clear

public void clear()

Description copied from class: DataStructure

Clears this data structure by removing all content from it.

Overrides:

clear in class DataStructure

add

public boolean add(java.lang.Object obj)

Description copied from class: DataStructure

Adds a new object to this data structure.

Overrides:

add in class DataStructure

Parameters:

obj - the object to add

Returns:

true if the object was actually added, false in any other case (e.g. adding an object to a set which already contains the same object in terms of java.lang.Object.equals(Object))

addAll

public boolean addAll(DataStructure data)

Description copied from class: DataStructure

Adds all objects contained within data to this instance.

Overrides:

addAll in class DataStructure

Parameters:

data - the objects to add

Returns:

true if at least one object from data was actually added, i.e. a modification was made to this instance, false in any other case (e.g. adding objects to a set which already contains them in terms of java.lang.Object.equals(Object))

containsAll

public boolean containsAll(DataStructure data)

Description copied from class: DataStructure

Checks whether all items within data are present within this data structure instance and returns true only if this is the case.

Overrides:

containsAll in class DataStructure

Parameters:

data - the items to check the presence of

Returns:

true if all objects within data are contained by this instance, false if at least one of them is not

isEmpty

public boolean isEmpty()

Description copied from class: DataStructure

Checks whether this instance is empty or not.

Overrides:

isEmpty in class DataStructure

Returns:

true if this data structure is empty, false otherwise

toArray

public java.lang.Object[] toArray()

Description copied from class: DataStructure

Returns an array containing all items stored within this data structure. The array will be of length DataStructure.size(), i.e. for an empty data structure an array of length zero is returned (rather than null).

Overrides:

toArray in class DataStructure

Returns:

an array of all objects contained within this data structure instance; this method never returns null

toArray

public java.lang.Object[] toArray(java.lang.Object[] object)

Description copied from class: DataStructure

Stores all contained items into the passed-in array objects. Returns the same array.

The array is expected not to be null and to be of exactly DataStructure.size() length. Otherwise, either a java.lang.NullPointerException or an java.lang.IllegalArgumentException will be thrown.

Overrides:

toArray in class DataStructure

Parameters:

object - the array to store this data structure's content to

Returns:

the same array as the one passed in (objects), however after having been filled with all objects contained within this data structure instance

hashCode

public int hashCode()

Overrides:

hashCode in class DataStructure

equals

public boolean equals(java.lang.Object o)

Overrides:

equals in class java.lang.Object

toString

public java.lang.String toString()

Overrides:

toString in class DataStructure