com.partnersoft.formats.text

Class LineTextDataRecordSource

java.lang.Object

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

com.partnersoft.io.DataRecordSource

com.partnersoft.formats.text.LineTextDataRecordSource

All Implemented Interfaces:

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

Direct Known Subclasses:

CsvDataRecordSource

public abstract class LineTextDataRecordSource
extends DataRecordSource

An abstract DataRecordSource for data formatted as a text file with line feeds and/or carriage returns separating the data records. Examples include fixed-width text formats, comma-separated, tab-separated, etc.

Subclasses must provide the code for parsing field values from each line. This is done by implementing the parseLine(String) method.

This class takes care of opening and closing the file, tracking line numbers, etc.

Copyright 2006-2007 Partner Software, Inc.

Author:

Paul Reavis

Nested Class Summary

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

IterableInput.Status

Field Summary

Fields

Modifier and Type	Field and Description
java.lang.String	currentLine
int	currentLineNumber

Fields inherited from class com.partnersoft.io.DataRecordSource

currentValues, fieldNames, verbose

Constructor Summary

Constructors

Constructor and Description
LineTextDataRecordSource()
LineTextDataRecordSource(Cog state)
LineTextDataRecordSource(VfsFile file)
LineTextDataRecordSource(VfsFile file, java.util.List<java.lang.String> fieldNames)
LineTextDataRecordSource(VfsFile file, java.lang.String... fieldNames)

Method Summary

Methods

Modifier and Type	Method and Description
void	closeImp() Subclass implementation of guts of close() method.
boolean	fetchImp() Subclass implementation of guts of fetch() method.
VfsFile	getFile()
void	open() Initialize the input, opening the underlying file or other resource.
void	openImp() Subclass implementation of guts of open() method.
abstract boolean	parseLine(java.lang.String line) Subclasses must implement this.
protected java.lang.String	readLine() Reads a line and returns the result.

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, getException, getStatus, isFetchValid, iterator

Methods inherited from class java.lang.Object

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

Field Detail

currentLineNumber

public transient int currentLineNumber

currentLine

public transient java.lang.String currentLine

Constructor Detail

LineTextDataRecordSource

public LineTextDataRecordSource()

LineTextDataRecordSource

public LineTextDataRecordSource(VfsFile file)

LineTextDataRecordSource

public LineTextDataRecordSource(VfsFile file,
                        java.util.List<java.lang.String> fieldNames)

LineTextDataRecordSource

public LineTextDataRecordSource(VfsFile file,
                        java.lang.String... fieldNames)

LineTextDataRecordSource

public LineTextDataRecordSource(Cog state)

Method Detail

open

public void open()

Description copied from interface: IterableInput

Initialize the input, opening the underlying file or other resource. Note that this does not start the actual fetch, and getFetched() will throw IllegalStateException until you do a fetch().

This method can only be called if the current status is CLOSED. Calling it in any other state will result in an IllegalStateException.

If the input is opened successfully, the status is changed to OPENED.

If an exception occurs during the open, the exception is made available via getException(), and the status is changed to END_OF_INPUT. This means close() should still be called.

Specified by:

open in interface IterableInput<Naming<java.lang.Object>>

Overrides:

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

openImp

public void openImp()
             throws java.lang.Exception

Description copied from class: AbstractIterableInput

Subclass implementation of guts of open() method.

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

Specified by:

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

Throws:

java.lang.Exception

fetchImp

public 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

closeImp

public void closeImp()
              throws java.lang.Exception

Description copied from class: AbstractIterableInput

Subclass implementation of guts of close() method.

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

Specified by:

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

Throws:

java.lang.Exception

parseLine

public abstract boolean parseLine(java.lang.String line)
                           throws java.lang.Exception

Subclasses must implement this. It should read the input string, representing a single line of input, set the currentValues array in DataRecordSource, and return true if successful.

Parameters:

line -

Returns:

Throws:

java.lang.Exception

getFile

public VfsFile getFile()

readLine

protected java.lang.String readLine()
                             throws java.lang.Exception

Reads a line and returns the result. Also increments currentLineNumber and sets currentLine to the same value as returned. This consumes the line; calling it multiple times gets you each line in the file in turn. Interleaving this with calls to an iterator will cause gaps. Use with caution.

Throws:

java.lang.Exception