Mega Code Archive
Simple scanner that allows to navigate over the characters of a string
<![CDATA[
/*
* SSHTools - Java SSH2 API
*
* Copyright (C) 2002-2003 Lee David Painter and Contributors.
*
* Contributions made by:
*
* Brett Smith
* Richard Pernavas
* Erwin Bolwidt
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
//
// CONTENT : CLASS StringScanner
// AUTHOR : Manfred Duchrow
// VERSION : 1.1 - 29/09/2002
// HISTORY :
// 11/07/2001 duma CREATED
// 29/09/2002 duma added -> endReached(), endNotReached()
//
// Copyright (c) 2001-2002, by Manfred Duchrow. All rights reserved.
//package com.sshtools.daemon.util;
// IMPORTS
/**
* Simple scanner that allows to navigate over the characters of a string.
*
* @author Manfred Duchrow
* @version 1.1
*/
public class StringScanner {
// CONSTANTS
/** */
public static final char END_REACHED = (char) -1;
// INSTANCE VARIABLES
/** */
protected int length = 0;
/** */
protected int position = 0;
/** */
protected int pos_marker = 0;
/** */
protected char[] buffer = null;
// -------------------------------------------------------------------------
// CONSTRUCTORS
/**
* Initialize the new instance with the string that should be scanned.
*
* @param stringToScan
*/
public StringScanner(String stringToScan) {
super();
length = stringToScan.length();
buffer = new char[length];
stringToScan.getChars(0, length, buffer, 0);
}
// StringScanner()
// PUBLIC CLASS METHODS
/**
* Returns true, if the given character indicates that the end of the
* scanned string is reached.
*
* @param character
*
* @return
*/
public boolean endReached(char character) {
return (character == END_REACHED);
}
// endReached()
// -------------------------------------------------------------------------
/**
* Returns true, if the given character does <b>not</b> indicate that the
* end of the scanned string si reached.
*
* @param character
*
* @return
*/
public boolean endNotReached(char character) {
return (!endReached(character));
}
// endNotReached()
// PUBLIC INSTANCE METHODS
/**
* Returns the string the scanner was initialized with
*
* @return
*/
public String toString() {
return new String(buffer);
}
// toString()
// -------------------------------------------------------------------------
/**
* Moves the position pointer count characters. positive values move
* forwards, negative backwards. The position never becomes negative !
*
* @param count
*/
public void skip(int count) {
position += count;
if (position < 0) {
position = 0;
}
}
// skip()
// -------------------------------------------------------------------------
/**
* Returns the character at the current position without changing the
* position, that is subsequent calls to this method return always the
* same character.
*
* @return
*/
public char peek() {
return ((position < length()) ? buffer[position] : END_REACHED);
}
// skip()
// -------------------------------------------------------------------------
/**
* Returns the character at the current position and increments the
* position afterwards by 1.
*
* @return
*/
public char nextChar() {
char next = this.peek();
if (endNotReached(next)) {
this.skip(1);
}
return next;
}
// nextChar()
// -------------------------------------------------------------------------
/**
* Returns true, if the scanner has reached the end and a further
* invocation of nextChar() would return the END_REACHED character.
*
* @return
*/
public boolean atEnd() {
return (endReached(this.peek()));
}
// atEnd()
// -------------------------------------------------------------------------
/**
* Returns true, if the scanner has not yet reached the end.
*
* @return
*/
public boolean hasNext() {
return !this.atEnd();
}
// hasNext()
// -------------------------------------------------------------------------
/**
* Returns the next character that is no whitespace and leaves the position
* pointer one character after the returned one.
*
* @return
*/
public char nextNoneWhitespaceChar() {
char next = this.nextChar();
while ((endNotReached(next)) && (Character.isWhitespace(next))) {
next = this.nextChar();
}
return next;
}
// nextNoneWhitespaceChar()
// -------------------------------------------------------------------------
/**
* Returns the current position in the string
*
* @return
*/
public int getPosition() {
return position;
}
// getPosition()
// -------------------------------------------------------------------------
/**
* Remembers the current position for later use with restorePosition()
*/
public void markPosition() {
pos_marker = position;
}
// markPosition()
// -------------------------------------------------------------------------
/**
* Restores the position to the value of the latest markPosition() call
*/
public void restorePosition() {
this.setPosition(pos_marker);
}
// restorePosition()
/**
*
*
* @return
*/
protected int length() {
return length;
}
// length()
// -------------------------------------------------------------------------
protected void setPosition(int pos) {
if ((pos >= 0) && (pos <= this.length())) {
position = pos;
}
}
// setPosition()
// -------------------------------------------------------------------------
}
// class StringScanner
]]>