com.partnersoft.io
Class RandomAccessDataRecordSource

java.lang.Object
  com.partnersoft.io.AbstractIterableInput<Naming<java.lang.Object>>
      com.partnersoft.io.DataRecordSource
          com.partnersoft.io.RandomAccessDataRecordSource

All Implemented Interfaces:

Coggable, IterableInput<Naming<java.lang.Object>>, java.lang.Iterable<Naming<java.lang.Object>>

public abstract class RandomAccessDataRecordSource
extends DataRecordSource

Superclass for DataRecordSources whose records can also be retrieved via a numeric index.

Provides a basic implementation of fetchImp() that keeps track of a recordCount and currentRecordNumber; it simply iterates through the numbers 0 <= currentRecordNumber < recordCount. You should set recordCount on open. Copyright 2008 Partner Software, Inc.

Version:

$Id$

Author:

Paul Reavis

Nested Class Summary

Nested classes/interfaces inherited from interface com.partnersoft.io.IterableInput

IterableInput.Status

Field Summary

int	currentRecordNumber
int	recordCount

Fields inherited from class com.partnersoft.io.DataRecordSource

currentValues, fieldNames, verbose

Constructor Summary

RandomAccessDataRecordSource()

Method Summary

protected boolean	fetchImp() Subclass implementation of guts of fetch() method.
Naming<java.lang.Object>	fetchRecordAt(int recordNumber) Return the record at the given number.
abstract java.lang.Object[]	fetchValuesAt(int recordNumber) Return the values for the record at the given number.
int	getRecordCount()

Methods inherited from class com.partnersoft.io.DataRecordSource

copy, fetch, getCurrentValues, getFetched, getFieldNames, isVerbose, setVerbose, toCog

Methods inherited from class com.partnersoft.io.AbstractIterableInput

close, closeImp, getException, getStatus, isFetchValid, iterator, open, openImp

Methods inherited from class java.lang.Object

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

Field Detail

currentRecordNumber

public int currentRecordNumber

recordCount

public int recordCount

Constructor Detail

RandomAccessDataRecordSource

public RandomAccessDataRecordSource()

Method Detail

fetchValuesAt

public abstract java.lang.Object[] fetchValuesAt(int recordNumber)

Return the values for the record at the given number. Returns null if the fetch fails for any reason.

Subclasses must implement this to take care of the actual fetching.

Parameters:

recordNumber - number of the record desired, starting with zero.

Returns:

values for the record at recordNumber

fetchRecordAt

public Naming<java.lang.Object> fetchRecordAt(int recordNumber)

Return the record at the given number. Returns null if the fetch fails for any reason.

Parameters:

recordNumber - number of the record desired, starting with zero.

Returns:

record at recordNumber

fetchImp

protected boolean fetchImp()
                    throws java.lang.Exception

Description copied from class: AbstractIterableInput

Subclass implementation of guts of fetch() method.

Subclasses must implement this to do the actual work required by fetch(). Feel free to throw exceptions; these are caught inside the fetch() itself and applied to the exception variable. Thus, you can focus on the actual task instead of paperwork.

Specified by:

fetchImp in class AbstractIterableInput<Naming<java.lang.Object>>

Returns:

true if fetch successful

Throws:

java.lang.Exception

getRecordCount

public int getRecordCount()