net.sf.statcvs.util
Class LookaheadReader

java.lang.Object
  net.sf.statcvs.util.LookaheadReader

public class LookaheadReader
extends java.lang.Object

Wraps a Reader for line-by-line access. This works like Iterator: hasNextLine() returns true if another line can be read; nextLine reads the next line and returns it. Additionally, getCurrentLine() can be used to access multiple times the line returned by nextLine().

At construction time, getCurrentLine() is undefined. nextLine() must be called once to read the first line.

Version:

$Id: LookaheadReader.java,v 1.4 2008/04/02 11:22:15 benoitx Exp $

Author:

Richard Cyganiak (richard@cyganiak.de)

Constructor Summary

LookaheadReader(java.io.Reader reader)
Creates a LookaheadReader from a source reader.

Method Summary

java.lang.String	getCurrentLine() Returns the current line without reading a line from the source reader.
int	getLineNumber() Returns the number of the line that would be returned by getCurrentLine(), or 0 before the first call to nextLine.
boolean	hasNextLine() Checks if more lines are available for reading.
java.lang.String	nextLine() Reads and returns a line from the source reader.

Methods inherited from class java.lang.Object

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

Constructor Detail

LookaheadReader

public LookaheadReader(java.io.Reader reader)

Creates a LookaheadReader from a source reader.

Parameters:

reader - a reader whose contents will be returned by the LookaheadReader

Method Detail

getCurrentLine

public java.lang.String getCurrentLine()

Returns the current line without reading a line from the source reader. Will throw an exception if nextLine was not called before.

Returns:

The line returned by the previous call to nextLine()

Throws:

java.util.NoSuchElementException - if nextLine was not yet called

nextLine

public java.lang.String nextLine()
                          throws java.io.IOException

Reads and returns a line from the source reader. The result of this call will be the new current line. Will throw an exception if trying to read from after the end of the source reader.

Returns:

The next line of the source reader

Throws:

java.io.IOException - on error while reading the source reader

java.util.NoSuchElementException - if hasNextLine() is false

hasNextLine

public boolean hasNextLine()
                    throws java.io.IOException

Checks if more lines are available for reading.

Returns:

true if at least one more line can be read

Throws:

java.io.IOException - on error while reading the source reader

getLineNumber

public int getLineNumber()

Returns the number of the line that would be returned by getCurrentLine(), or 0 before the first call to nextLine. The first line has line number 1.

Returns:

the current line number