org.marc4j

Class MarcCombiningReader

java.lang.Object

org.marc4j.MarcCombiningReader

All Implemented Interfaces:

MarcReader

public class MarcCombiningReader
extends Object
implements MarcReader

Binary MARC records have a maximum size of 99999 bytes. In the data dumps from the Sirsi/Dynix Virgo system if a record with all of its holdings information attached would be greater that that size, the records is written out multiple times with each subsequent record containing a subset of the total holdings information. This class reads ahead to determine when the next record in a MaARC file is actually a continuation of the same record. When this occurs, the holdings information in the next record is appended to/merged with the in-memory MARC record representation already read.

Author:

rh9ec

Constructor Summary

Constructors

Constructor and Description
MarcCombiningReader(MarcReader reader, ErrorHandler currentErrors, ErrorHandler nextErrors, String idsToMerge, String leftControlField, String rightControlField) Constructor for a "combining" Marc reader, that looks ahead at the Marc file to determine when the next record is a continuation of the currently read record.
MarcCombiningReader(MarcReader reader, String idsToMerge, String leftControlField, String rightControlField) Constructor for a "combining" Marc reader, that looks ahead at the Marc file to determine when the next record is a continuation of the currently read record.

Method Summary

Methods

Modifier and Type	Method and Description
static Record	combineRecords(Record currentRecord, Record nextRecord, String idsToMerge) Combines fields (identified by the idsToMerge) from the second Record into the first.
static Record	combineRecords(Record currentRecord, Record nextRecord, String idsToMerge, String fieldInsertBefore) Combines fields (identified by the idsToMerge from the second Record into the first (before the supplied field).
boolean	hasNext() Returns true if there is a next record; else false.
Record	next() Returns the next Record record if there is one and null if there isn't.

Methods inherited from class java.lang.Object

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

Constructor Detail

MarcCombiningReader

public MarcCombiningReader(MarcReader reader,
                   String idsToMerge,
                   String leftControlField,
                   String rightControlField)

Constructor for a "combining" Marc reader, that looks ahead at the Marc file to determine when the next record is a continuation of the currently read record.

Parameters:

reader - - The Lower level MarcReader that returns Marc4J Record objects that are read from a Marc file.

idsToMerge - - string representing a regular expression matching those fields to be merged for continuation records.

leftControlField - - string representing a control field in the current record to use for matching purposes (null to default to 001).

rightControlField - - string representing a control field in the next record to use for matching purposes (null to default to 001).

MarcCombiningReader

public MarcCombiningReader(MarcReader reader,
                   ErrorHandler currentErrors,
                   ErrorHandler nextErrors,
                   String idsToMerge,
                   String leftControlField,
                   String rightControlField)

Constructor for a "combining" Marc reader, that looks ahead at the Marc file to determine when the next record is a continuation of the currently read record. Because this reader needs to have two records in memory to determine when the subsequent record is a continuation, if Error Handling is being performed, this constructor needs to be used, so that the errors from the "next" record are not appended to the results for the "current" record. Call this constructor in the following way: ErrorHandler errors2 = errors; errors = new ErrorHandler(); reader = new MarcCombiningReader(reader, errors, errors2, combineConsecutiveRecordsFields);

Parameters:

reader - - The Lower level MarcReader that returns Marc4J Record objects that are read from a Marc file.

currentErrors - - ErrorHandler Object to use for attaching errors to a record.

nextErrors - - ErrorHandler Object that was passed into the lower level MarcReader

idsToMerge - - string representing a regular expression matching those fields to be merged for continuation records.

leftControlField - - string representing a control field in the current record to use for matching purposes (null to default to 001).

rightControlField - - string representing a control field in the next record to use for matching purposes (null to default to 001).

Method Detail

hasNext

public boolean hasNext()

Returns true if there is a next record; else false.

Specified by:

hasNext in interface MarcReader

next

public Record next()

Returns the next Record record if there is one and null if there isn't.

Specified by:

next in interface MarcReader

Returns:

Record - the record object

combineRecords

public static Record combineRecords(Record currentRecord,
                    Record nextRecord,
                    String idsToMerge)

Combines fields (identified by the idsToMerge) from the second Record into the first.

Parameters:

currentRecord -

nextRecord -

idsToMerge -

Returns:

combineRecords

public static Record combineRecords(Record currentRecord,
                    Record nextRecord,
                    String idsToMerge,
                    String fieldInsertBefore)

Combines fields (identified by the idsToMerge from the second Record into the first (before the supplied field).

Parameters:

currentRecord -

nextRecord -

idsToMerge -

fieldInsertBefore -

Returns: