org.deri.tarql

Class CSVParser

java.lang.Object

org.deri.tarql.CSVParser

All Implemented Interfaces:

com.hp.hpl.jena.util.iterator.ClosableIterator<com.hp.hpl.jena.sparql.engine.binding.Binding>, java.util.Iterator<com.hp.hpl.jena.sparql.engine.binding.Binding>

public class CSVParser
extends java.lang.Object
implements com.hp.hpl.jena.util.iterator.ClosableIterator<com.hp.hpl.jena.sparql.engine.binding.Binding>

Parses a CSV file presented as a Reader, and delivers results as an iterator of Bindings. Also provides access to the variable names (which may come from row 1 or could be auto-generated).

Adds a ROWNUM column with the number of the row.

Field Summary

Fields

Modifier and Type	Field and Description
private static java.lang.String	alphabet
private com.hp.hpl.jena.sparql.engine.binding.Binding	binding
private au.com.bytecode.opencsv.CSVReader	csv
private char	delimiter
private java.lang.Character	escape
private char	quote
private java.io.Reader	reader
private int	rownum
private org.apache.commons.validator.routines.UrlValidator	urlValidator
private java.util.List<com.hp.hpl.jena.sparql.core.Var>	vars
private boolean	varsFromHeader

Constructor Summary

Constructors

Constructor and Description
CSVParser(java.io.Reader reader, boolean varsFromHeader, java.lang.Character delimiter, java.lang.Character quote, java.lang.Character escape) Class constructor.

Method Summary

Methods

Modifier and Type	Method and Description
void	close()
private java.lang.String	formatColumnName(java.lang.String s) Format column names with the following rules.
static java.lang.String	getColumnName(int i) Get a default column name for a column index.
private com.hp.hpl.jena.sparql.core.Var	getVar(int column) Get variable in the CSV at a given column.
java.util.List<com.hp.hpl.jena.sparql.core.Var>	getVars() Get all variables from the CSV file.
boolean	hasNext()
private void	init() Init method setting up the CSV source and reading the variables from it.
private boolean	isEmpty(java.lang.String[] row) Check if the CSV row is empty.
private boolean	isUnboundValue(java.lang.String value) Checks whether a string taken from a CSV cell is considered an unbound SPARQL value.
private boolean	isURL(java.lang.String s) Check if a string is a valid URL.
com.hp.hpl.jena.sparql.engine.binding.Binding	next()
void	remove()
private java.lang.String	sanitizeString(java.lang.String s) Remove/replace weird characters known to cause problems in RDF toolkits.
private java.lang.String	sanitizeUrl(java.lang.String s) Remove '<' and '>' symbols from a URL if present.
private com.hp.hpl.jena.sparql.engine.binding.Binding	toBinding(java.lang.String[] row) Get a Binding object representing a CSV row.
private com.hp.hpl.jena.sparql.core.Var	toVar(java.lang.String s) Get a Var object from a column name.

Methods inherited from class java.lang.Object

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

Field Detail

alphabet

private static final java.lang.String alphabet

See Also:

Constant Field Values

reader

private final java.io.Reader reader

varsFromHeader

private final boolean varsFromHeader

delimiter

private final char delimiter

quote

private final char quote

escape

private final java.lang.Character escape

vars

private final java.util.List<com.hp.hpl.jena.sparql.core.Var> vars

rownum

private int rownum

urlValidator

private org.apache.commons.validator.routines.UrlValidator urlValidator

binding

private com.hp.hpl.jena.sparql.engine.binding.Binding binding

csv

private au.com.bytecode.opencsv.CSVReader csv

Constructor Detail

CSVParser

public CSVParser(java.io.Reader reader,
         boolean varsFromHeader,
         java.lang.Character delimiter,
         java.lang.Character quote,
         java.lang.Character escape)
          throws java.io.IOException

Class constructor.

Parameters:

reader - Reader over the contents of a CSV file

varsFromHeader - If true, use values of first row as column names

delimiter - The delimiter character to use for separating entries (e.g., ',' or ';' or '\t'), or null for default

quote - The quote character used to quote values (typically double or single quote), or null for default

escape - The escape character for quotes and delimiters, or null for none

Throws:

java.io.IOException

Method Detail

init

private void init()
           throws java.io.IOException

Init method setting up the CSV source and reading the variables from it.

Throws:

java.io.IOException

toBinding

private com.hp.hpl.jena.sparql.engine.binding.Binding toBinding(java.lang.String[] row)

Get a Binding object representing a CSV row.

Parameters:

row - CSV row.

Returns:

Binding representation of row.

getVars

public java.util.List<com.hp.hpl.jena.sparql.core.Var> getVars()

Get all variables from the CSV file.

Returns:

List of variables.

getVar

private com.hp.hpl.jena.sparql.core.Var getVar(int column)

Get variable in the CSV at a given column.

Parameters:

column - Column index.

Returns:

Variable represented in the column.

toVar

private com.hp.hpl.jena.sparql.core.Var toVar(java.lang.String s)

Get a Var object from a column name.

Parameters:

s - Input column name.

Returns:

Var representation of the column name.

getColumnName

public static java.lang.String getColumnName(int i)

Get a default column name for a column index.

Parameters:

i - Column index.

Returns:

Column name at index i.

isEmpty

private boolean isEmpty(java.lang.String[] row)

Check if the CSV row is empty.

Parameters:

row - CSV row.

Returns:

true if row is empty; false otherwise.

isUnboundValue

private boolean isUnboundValue(java.lang.String value)

Checks whether a string taken from a CSV cell is considered an unbound SPARQL value.

Parameters:

value - CSV cell value.

Returns:

true if value is empty or null; false otherwise.

sanitizeString

private java.lang.String sanitizeString(java.lang.String s)

Remove/replace weird characters known to cause problems in RDF toolkits.

Parameters:

s - Input String.

Returns:

Clean String s.

sanitizeUrl

private java.lang.String sanitizeUrl(java.lang.String s)

Remove '<' and '>' symbols from a URL if present.

Parameters:

s - Input URL.

Returns:

Clean URL.

formatColumnName

private java.lang.String formatColumnName(java.lang.String s)

Format column names with the following rules.

• replace whitespaces by '_'
• replace dash by '_'
• replace '?' by '_'
• remove last dot
• replace dots by '_'

Parameters:

s - Input column name.

Returns:

Formatted column name.

isURL

private boolean isURL(java.lang.String s)

Check if a string is a valid URL.

Parameters:

s - Input String.

Returns:

true if `s` is a URL; false otherwise.

hasNext

public boolean hasNext()

Specified by:

hasNext in interface java.util.Iterator<com.hp.hpl.jena.sparql.engine.binding.Binding>

next

public com.hp.hpl.jena.sparql.engine.binding.Binding next()

Specified by:

next in interface java.util.Iterator<com.hp.hpl.jena.sparql.engine.binding.Binding>

remove

public void remove()

Specified by:

remove in interface java.util.Iterator<com.hp.hpl.jena.sparql.engine.binding.Binding>

close

public void close()

Specified by:

close in interface com.hp.hpl.jena.util.iterator.ClosableIterator<com.hp.hpl.jena.sparql.engine.binding.Binding>