com.ibm.able.beans
Class AbleDataSet

java.lang.Object
  com.ibm.able.beans.AbleDataSet

All Implemented Interfaces:

AbleImportData, java.io.Serializable

public class AbleDataSet

extends java.lang.Object

implements AbleImportData, java.io.Serializable

This class describes and reads a text file. It uses an external data set called a definition file *.dfn which describes the field name, type (continuous/discrete/categorical), and usage (input/output/ignore). It reads a block of records specified by bufferSize into a textData vector where each element consists of an array of String objects.

See Also:

Serialized Form

Field Summary

protected boolean	allNumericData A boolean indicating whether all fields in the data source are continuous.
protected int	bufferSize An integer specifying the number of records to read from the database table and insert into the textData Vector.
protected java.lang.String	delimiter The delimiter is the character from the DelimiterChars Vector used to separate fields for this text file.
protected java.util.Vector	fieldList A Vector of AbleField elements in order of definition; ie, Vector index equals column number.
protected java.lang.String	fileName The path and file name to the definition and data files to be read.
protected java.io.BufferedReader	in The BufferedReader used to read the file.
static int	MAX_BUFFER_SIZE The maximum number of records which may be read.
protected long	numRecords A long calculated to be the number of records in the database table.
protected boolean	ready A boolean indicating whether the file is ready for processing.
protected java.util.Vector	textData A Vector of String arrays containing records from the file.

Constructor Summary

AbleDataSet(java.lang.String fileName)
Construct an AbleDataSet object for a given file.

Method Summary

void	close() Close the BufferedReader on the data file (if open).
protected AbleField	createAbleField(AbleFieldDefinition definition) Construct a corresponding AbleField from an AbleFieldDefinition.
void	displayVariables() Display the fieldList and its values.
int	getBufferSize() Return the number of records to place in the textData Vector each time a record block is read with readNextRecordBlock.
java.lang.String	getDelimiter()
java.util.Vector	getFieldList() Return a Vector of AbleField objects where each object describes a data column.
int	getNumFieldsPerRec() Return the number of fields in each record.
long	getNumRecords() Return the number of records in this database table.
java.util.Vector	getTextData() Returns a Vector of String[] objects representing all loaded text data.
boolean	isAllNumericData() Returns true if all fields are "continuous", false if any are "discrete" or "categorical"; that is, symbols.
boolean	isReady() Return a boolean indicating whether or not the file is ready for processing.
void	loadDataFile() Load the entire data file from a text file into a vector of String arrays.
void	open() Open the data set definition named fileName.
void	readNextRecordBlock() Read the next n records from a file into a vector of String arrays.
void	reopen() Reopen (recreate) the BufferedReader on the text file.
void	setBufferSize(int size) Set the number of records to place in the textData Vector each time a record block is read with readNextRecordBlock.
void	setDelimiter(java.lang.String delimiter)
void	setFieldList(java.util.Vector fieldList) Set a Vector of AbleField objects where each object describes a data column.

Methods inherited from class java.lang.Object

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

Field Detail

MAX_BUFFER_SIZE

public static final int MAX_BUFFER_SIZE

The maximum number of records which may be read.

See Also:

Constant Field Values

fileName

protected java.lang.String fileName

The path and file name to the definition and data files to be read.

in

protected transient java.io.BufferedReader in

The BufferedReader used to read the file.

allNumericData

protected boolean allNumericData

A boolean indicating whether all fields in the data source are continuous.

textData

protected java.util.Vector textData

A Vector of String arrays containing records from the file. The Vector contains all records if bufferSize is 0.

fieldList

protected java.util.Vector fieldList

A Vector of AbleField elements in order of definition; ie, Vector index equals column number.

bufferSize

protected int bufferSize

An integer specifying the number of records to read from the database table and insert into the textData Vector. A value of 0 means all records are to be read.

numRecords

protected long numRecords

A long calculated to be the number of records in the database table.

delimiter

protected java.lang.String delimiter

The delimiter is the character from the DelimiterChars Vector used to separate fields for this text file. Default is blank white space (" ").

ready

protected boolean ready

A boolean indicating whether the file is ready for processing.

Constructor Detail

AbleDataSet

public AbleDataSet(java.lang.String fileName)

Construct an AbleDataSet object for a given file.

Parameters:

fileName - A String containing the path and name for the definition and data file to read.

Method Detail

isReady

public boolean isReady()

Return a boolean indicating whether or not the file is ready for processing.

Specified by:

isReady in interface AbleImportData

displayVariables

public void displayVariables()

Display the fieldList and its values.

createAbleField

protected AbleField createAbleField(AbleFieldDefinition definition)
                             throws AbleException

Construct a corresponding AbleField from an AbleFieldDefinition. Categorical, continuous, and discrete are supported.

Parameters:

definition - An AbleFieldDefinition.

Returns:

A corresponding AbleField object.

Throws:

An - exception if the AbleFieldDefinition provided is unsupported.

AbleException

getNumFieldsPerRec

public int getNumFieldsPerRec()

Return the number of fields in each record.

Specified by:

getNumFieldsPerRec in interface AbleImportData

open

public void open()
          throws AbleException

Open the data set definition named fileName. Create a BufferedReader over the specified text file, read the *.dfn file and create the fieldList if needed for this data set. Read each record in the data file, and populate the textData Vector with as many records as specified by the bufferSize.

Specified by:

open in interface AbleImportData

Throws:

AbleException

reopen

public void reopen()
            throws AbleException

Reopen (recreate) the BufferedReader on the text file. This should only be called directly when the file has changed. It does not reload the data definition.

Throws:

AbleException

close

public void close()

Close the BufferedReader on the data file (if open).

Specified by:

close in interface AbleImportData

loadDataFile

public void loadDataFile()
                  throws AbleException

Load the entire data file from a text file into a vector of String arrays. Assumes the data file definition (variables) has already been loaded.

Throws:

AbleException

readNextRecordBlock

public void readNextRecordBlock()
                         throws AbleException

Read the next n records from a file into a vector of String arrays. Assumes that the fieldList and textData Vectors have already been created, and the file opened. When the last record in the file is found, wrap back to the first record and continue populating elements of the textData Vector until its size reaches the bufferSize.

Specified by:

readNextRecordBlock in interface AbleImportData

Throws:

AbleException

getTextData

public java.util.Vector getTextData()

Returns a Vector of String[] objects representing all loaded text data. Note: This represents the original data as read from the file.

Specified by:

getTextData in interface AbleImportData

isAllNumericData

public boolean isAllNumericData()

Returns true if all fields are "continuous", false if any are "discrete" or "categorical"; that is, symbols.

Specified by:

isAllNumericData in interface AbleImportData

setBufferSize

public void setBufferSize(int size)

Set the number of records to place in the textData Vector each time a record block is read with readNextRecordBlock.

Specified by:

setBufferSize in interface AbleImportData

getBufferSize

public int getBufferSize()

Return the number of records to place in the textData Vector each time a record block is read with readNextRecordBlock.

Specified by:

getBufferSize in interface AbleImportData

getFieldList

public java.util.Vector getFieldList()

Return a Vector of AbleField objects where each object describes a data column.

Specified by:

getFieldList in interface AbleImportData

setFieldList

public void setFieldList(java.util.Vector fieldList)

Set a Vector of AbleField objects where each object describes a data column.

Specified by:

setFieldList in interface AbleImportData

getNumRecords

public long getNumRecords()

Return the number of records in this database table.

Specified by:

getNumRecords in interface AbleImportData

getDelimiter

public java.lang.String getDelimiter()

setDelimiter

public void setDelimiter(java.lang.String delimiter)