org.freehep.record.source

Class AbstractRecordSource

java.lang.Object

org.freehep.record.source.AbstractRecordSource

All Implemented Interfaces:

RecordSource

Direct Known Subclasses:

TagListRecordSource

public abstract class AbstractRecordSource
extends Object
implements RecordSource

Adapter that simplifies implementing RecordSource. Provides implementations for all methods except RecordSource.getCurrentRecord().

As implemented, this source supports no positioning operations. All supportsXXX methods return false. All hasXXX methods forward the call to supportsXXX. All positioning methods throw UnsupportedOperationException. A typical subclass that supports a certain subset of access modes will only need to override methods corresponding to those modes. For example, a simple sequential access source with no rewind capability will override supportsNext(), hasNext(), next(), and possibly size() if the number of records in the source is known.

Version:

$Id$

Author:

Dmitry Onoprienko

Constructor Summary

Constructors

Constructor and Description
AbstractRecordSource()
AbstractRecordSource(String name)

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Close the record source and release any associated resources.
void	current() Reloads the current record.
long	getCurrentIndex() Returns the index of the current record.
RecordTag	getCurrentTag() Returns the tag of the current record.
long	getEstimatedSize() Returns the estimated number of records in this source.
String	getName() Returns the name of this source.
Class<?>	getRecordClass() Returns the Class object that is guaranteed to be a superclass of all records in this source.
List<RecordTag>	getTags() Returns a list of tags for events in this source.
boolean	hasCurrent() Returns true if this source can reload the current record.
boolean	hasIndex(long index) Returns true if this source has a record with the specified index.
boolean	hasNext() Returns true if this source can load the next record.
boolean	hasPrevious() Returns true if this source can load the previous record.
boolean	hasRewind() Returns true if this source in its current state can be rewound.
boolean	hasShift(long numberOfRecords) Returns true if this source can shift by numberOfRecords records.
boolean	hasTag(RecordTag tag) Returns true if this source has a record with the specified tag.
void	jump(long index) Loads the record specified by the index.
void	jump(RecordTag tag) Loads the record specified by the tag.
void	jump(String tagName) Loads the record specified by name.
void	next() Loads the next record.
RecordTag	parseTag(String s) Returns a tag corresponding to the specified string.
void	previous() Loads the previous record.
void	releaseRecord() Releases any resources associated with the current record.
void	rewind() Positions the cursor of this source before the first record.
void	setName(String name)
void	shift(long numberOfRecords) Loads the record specified by the offset with respect to the current cursor position.
long	size() Returns the number of records in this source.
boolean	supportsCurrent() Returns true if this source supports reloading current record.
boolean	supportsIndex() Returns true if this source supports selecting records by index.
boolean	supportsNext() Returns true if this source supports loading next record.
boolean	supportsPrevious() Returns true if this source supports loading previous record.
boolean	supportsRewind() Returns true if this source supports rewind operation.
boolean	supportsShift() Returns true if this source supports selecting records by offset with respect to the current record.
boolean	supportsTag() Returns true if this source supports selecting records by tag.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.freehep.record.source.RecordSource

getCurrentRecord

Constructor Detail

AbstractRecordSource

public AbstractRecordSource()

AbstractRecordSource

public AbstractRecordSource(String name)

Method Detail

setName

public void setName(String name)

getName

public String getName()

Returns the name of this source.

Specified by:

getName in interface RecordSource

getRecordClass

public Class<?> getRecordClass()

Returns the Class object that is guaranteed to be a superclass of all records in this source.

Implemented to return Object.class.

Specified by:

getRecordClass in interface RecordSource

size

public long size()

Returns the number of records in this source.

Implemented to throw UnsupportedOperationException.

Specified by:

size in interface RecordSource

getEstimatedSize

public long getEstimatedSize()

Returns the estimated number of records in this source.

Implemented to forward the call to size().

Specified by:

getEstimatedSize in interface RecordSource

getTags

public List<RecordTag> getTags()

Returns a list of tags for events in this source.

Implemented to throw UnsupportedOperationException.

Specified by:

getTags in interface RecordSource

getCurrentIndex

public long getCurrentIndex()

Returns the index of the current record.

Implemented to throw UnsupportedOperationException.

Specified by:

getCurrentIndex in interface RecordSource

getCurrentTag

public RecordTag getCurrentTag()

Returns the tag of the current record.

Implemented to throw UnsupportedOperationException.

Specified by:

getCurrentTag in interface RecordSource

releaseRecord

public void releaseRecord()

Releases any resources associated with the current record.

Implemented to do nothing.

Specified by:

releaseRecord in interface RecordSource

supportsCurrent

public boolean supportsCurrent()

Returns true if this source supports reloading current record.

Specified by:

supportsCurrent in interface RecordSource

supportsNext

public boolean supportsNext()

Returns true if this source supports loading next record.

Specified by:

supportsNext in interface RecordSource

supportsPrevious

public boolean supportsPrevious()

Returns true if this source supports loading previous record.

Specified by:

supportsPrevious in interface RecordSource

supportsIndex

public boolean supportsIndex()

Returns true if this source supports selecting records by index.

Specified by:

supportsIndex in interface RecordSource

supportsTag

public boolean supportsTag()

Returns true if this source supports selecting records by tag.

Specified by:

supportsTag in interface RecordSource

supportsShift

public boolean supportsShift()

Returns true if this source supports selecting records by offset with respect to the current record.

Specified by:

supportsShift in interface RecordSource

hasCurrent

public boolean hasCurrent()

Returns true if this source can reload the current record.

Specified by:

hasCurrent in interface RecordSource

hasNext

public boolean hasNext()

Returns true if this source can load the next record.

Specified by:

hasNext in interface RecordSource

hasPrevious

public boolean hasPrevious()

Returns true if this source can load the previous record.

Specified by:

hasPrevious in interface RecordSource

hasIndex

public boolean hasIndex(long index)

Returns true if this source has a record with the specified index.

Specified by:

hasIndex in interface RecordSource

hasTag

public boolean hasTag(RecordTag tag)

Returns true if this source has a record with the specified tag.

Specified by:

hasTag in interface RecordSource

hasShift

public boolean hasShift(long numberOfRecords)

Returns true if this source can shift by numberOfRecords records.

Specified by:

hasShift in interface RecordSource

current

public void current()
             throws IOException,
                    NoSuchRecordException

Reloads the current record.

Specified by:

current in interface RecordSource

Throws:

IOException - if reloading of the current record fails.

NoSuchRecordException - if there is no current record.

next

public void next()
          throws IOException,
                 NoSuchRecordException

Loads the next record.

Specified by:

next in interface RecordSource

Throws:

IOException - if loading of the next record fails.

NoSuchRecordException - if there is no next record.

previous

public void previous()
              throws IOException,
                     NoSuchRecordException

Loads the previous record.

Specified by:

previous in interface RecordSource

Throws:

IOException - if loading of the previous record fails.

NoSuchRecordException - if there is no previous record.

jump

public void jump(long index)
          throws IOException,
                 NoSuchRecordException

Loads the record specified by the index.

Specified by:

jump in interface RecordSource

Throws:

IOException - if loading of the requested record fails.

NoSuchRecordException - if this source does not have a record with the specified index.

jump

public void jump(RecordTag tag)
          throws IOException,
                 NoSuchRecordException

Loads the record specified by the tag.

Specified by:

jump in interface RecordSource

Throws:

IOException - if loading of the requested record fails.

NoSuchRecordException - if this source does not have a record with the specified tag.

shift

public void shift(long numberOfRecords)
           throws IOException,
                  NoSuchRecordException

Loads the record specified by the offset with respect to the current cursor position.

Specified by:

shift in interface RecordSource

Throws:

IOException - if loading of the requested record fails.

NoSuchRecordException - if this source does not have a record with the specified offset.

jump

public void jump(String tagName)
          throws IOException,
                 NoSuchRecordException

Loads the record specified by name. The specified name is converted to a record tag by calling parseTag(String).

Throws:

IOException

NoSuchRecordException

supportsRewind

public boolean supportsRewind()

Returns true if this source supports rewind operation.

Specified by:

supportsRewind in interface RecordSource

hasRewind

public boolean hasRewind()

Returns true if this source in its current state can be rewound.

Specified by:

hasRewind in interface RecordSource

rewind

public void rewind()
            throws IOException

Positions the cursor of this source before the first record.

Specified by:

rewind in interface RecordSource

Throws:

IOException - if rewinding fails for any reason.

close

public void close()
           throws IOException

Close the record source and release any associated resources.

Implemented to do nothing.

Specified by:

close in interface RecordSource

Throws:

IOException - if closing fails.

parseTag

public RecordTag parseTag(String s)

Returns a tag corresponding to the specified string.

Implemented to return an instance of DefaultRecordTag with the specified name.

Specified by:

parseTag in interface RecordSource