net.sf.basedb.util.parser
Class ColFunction

java.lang.Object
  net.sf.basedb.util.parser.ColFunction

All Implemented Interfaces:

JepFunction, org.nfunk.jep.function.PostfixMathCommandI

public class ColFunction
extends Object
implements JepFunction

Adds a col() function to Jep. The col function is used with the FlatFileParser to get the value of a data column. The argument to the col function is either the column name or index (0-based). Use the FlatFileParser.getMapper(String) with an argument starting with an equal sign to create a mapper that uses Jep.

FlatFileParser ffp = ...
Mapper diameterMapper = ffp.getMapper("=col('Radius') * 2");
while (ffp.hasMoreData())
{
        Data data = ffp.nextData();
        float diameter = diameterMapper.getFloat(data);
}

Version:

2.0

Author:

nicklas

Last modified

$Date: 2008-09-11 22:08:14 +0200 (Thu, 11 Sep 2008) $

Field Summary

private Map<String,Integer>	columnHeaders
private FlatFileParser.Data	data
private boolean	ignoreNonExistingColumns
private NumberFormat	numberFormat
private ParsePosition	pos

Constructor Summary

ColFunction(List<String> columnHeaders, NumberFormat numberFormat)

ColFunction(Map<String,Integer> columnHeaders, NumberFormat numberFormat)

Method Summary

boolean	checkNumberOfParameters(int n)
private Integer	findColumn(String regex) Find column index by checking each column header against a regular expression.
String	getFunctionName() Get the name of this function.
int	getNumberOfParameters()
void	run(Stack stack)
void	setCurNumberOfParameters(int n)
void	setData(FlatFileParser.Data data)
void	setIgnoreNonExistingColumns(boolean ignoreNonExistingColumns) Set to TRUE to ignore non-existing columns.

Methods inherited from class java.lang.Object

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

Field Detail

columnHeaders

private final Map<String,Integer> columnHeaders

numberFormat

private final NumberFormat numberFormat

pos

private final ParsePosition pos

data

private FlatFileParser.Data data

ignoreNonExistingColumns

private boolean ignoreNonExistingColumns

Constructor Detail

ColFunction

public ColFunction(Map<String,Integer> columnHeaders,
                   NumberFormat numberFormat)

ColFunction

public ColFunction(List<String> columnHeaders,
                   NumberFormat numberFormat)

Method Detail

getFunctionName

public String getFunctionName()

Description copied from interface: JepFunction

Get the name of this function. It is used when registering the function with a JEP parser.

Specified by:

getFunctionName in interface JepFunction

Returns:

The string "col"

See Also:

JEP.addFunction(String, PostfixMathCommandI)

getNumberOfParameters

public int getNumberOfParameters()

Specified by:

getNumberOfParameters in interface org.nfunk.jep.function.PostfixMathCommandI

Returns:

Always 1

setCurNumberOfParameters

public void setCurNumberOfParameters(int n)

Specified by:

setCurNumberOfParameters in interface org.nfunk.jep.function.PostfixMathCommandI

checkNumberOfParameters

public boolean checkNumberOfParameters(int n)

Specified by:

checkNumberOfParameters in interface org.nfunk.jep.function.PostfixMathCommandI

run

public void run(Stack stack)
         throws ParseException

Specified by:

run in interface org.nfunk.jep.function.PostfixMathCommandI

Throws:

ParseException

setIgnoreNonExistingColumns

public void setIgnoreNonExistingColumns(boolean ignoreNonExistingColumns)

Set to TRUE to ignore non-existing columns. Set to FALSE to throw an exception (default).

Since:

2.6

setData

public void setData(FlatFileParser.Data data)

findColumn

private Integer findColumn(String regex)

Find column index by checking each column header against a regular expression. The first match found is returned. The map is updated with a new regex -> index entry.

Returns:

The column index or null if no column is found or if the string is not a valid regular expression