org.osgl.util

Class BigLines

java.lang.Object

org.osgl.util.BigLines

All Implemented Interfaces:

Iterable<String>

public class BigLines
extends Object
implements Iterable<String>

A help class provide utilities that read through text file with big number of lines.

It supports:

1. preview the first line
2. get line numbers
3. skip lines
4. fetch certain number of lines

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	BigLines.LineReader

Constructor Summary

Constructors

Constructor and Description
BigLines(File file)

Method Summary

Modifier and Type	Method and Description
void	accept(BigLines.LineReader lineReader)
List<String>	cherrypick(int[] index)
String	fetch(int lineNumber) Returns the line specified by lineNumber.
List<String>	fetch(int offset, int limit) Returns a number of lines specified by start position offset and limit.
List<String>	fetchAround(int lineNumber, int before, int after)
String	firstLine()
String	getName()
boolean	isEmpty()
Iterator<String>	iterator()
int	lines()
static void	main(String[] args)
List<String>	preview() Returns first 5 lines including header line.
List<String>	preview(int limit) Returns first limit lines including header line.
List<String>	preview(int limit, boolean noHeaderLine) Returns first limit lines.
List<String>	sampling(int number)
void	setIterateFirstLine(boolean flag)

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Constructor Detail

BigLines

public BigLines(File file)

Method Detail

getName

public String getName()

isEmpty

public boolean isEmpty()

firstLine

public String firstLine()

lines

public int lines()

setIterateFirstLine

public void setIterateFirstLine(boolean flag)

preview

public List<String> preview()

Returns first 5 lines including header line.

preview

public List<String> preview(int limit)

Returns first limit lines including header line.

Parameters:

limit - the number of lines to be returned

Returns:

the first limit lines

preview

public List<String> preview(int limit,
                            boolean noHeaderLine)

Returns first limit lines.

Parameters:

limit - the number of lines to be returned

noHeaderLine - if false then header line will be excluded in the return list

Returns:

the first limit lines.

fetch

public String fetch(int lineNumber)

Returns the line specified by lineNumber.

Note the lineNumber starts with 0.

Parameters:

lineNumber - specify the line to be returned.

Returns:

the line as described above.

fetch

public List<String> fetch(int offset,
                          int limit)

Returns a number of lines specified by start position offset and limit.

Parameters:

offset - the start line number (0 based)

limit - the number of lines to be returned.

Returns:

a number of lines as specified.

fetchAround

public List<String> fetchAround(int lineNumber,
                                int before,
                                int after)

cherrypick

public List<String> cherrypick(int[] index)

sampling

public List<String> sampling(int number)

accept

public void accept(BigLines.LineReader lineReader)

iterator

public Iterator<String> iterator()

Specified by:

iterator in interface Iterable<String>

main

public static void main(String[] args)