/*
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* CDDL HEADER START
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*
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* The contents of this file are subject to the terms of the
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* Common Development and Distribution License, Version 1.0 only
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* (the "License"). You may not use this file except in compliance
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* with the License.
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*
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* You can obtain a copy of the license at
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* trunk/opendj3/legal-notices/CDDLv1_0.txt
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* or http://forgerock.org/license/CDDLv1.0.html.
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* See the License for the specific language governing permissions
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* and limitations under the License.
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*
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* When distributing Covered Code, include this CDDL HEADER in each
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* file and include the License file at
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* trunk/opendj3/legal-notices/CDDLv1_0.txt. If applicable,
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* add the following below this CDDL HEADER, with the fields enclosed
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* by brackets "[]" replaced with your own identifying information:
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* Portions Copyright [yyyy] [name of copyright owner]
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*
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* CDDL HEADER END
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*
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*
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* Copyright 2009-2010 Sun Microsystems, Inc.
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* Portions copyright 2012 ForgeRock AS.
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*/
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package com.forgerock.opendj.util;
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/**
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* A sub-string reader.
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*/
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public class SubstringReader
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{
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// The source string.
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private final String source;
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// The current position.
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private int pos;
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// The marked position.
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private int mark;
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// The length of the source.
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private final int length;
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/**
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* Creates an instance of SubstringReader.
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*
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* @param s
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* the source of the reader.
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*/
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public SubstringReader(final String s)
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{
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Validator.ensureNotNull(s);
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source = s;
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length = s.length();
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pos = 0;
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mark = 0;
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}
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/**
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* Returns the source string.
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*
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* @return source string.
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*/
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public String getString()
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{
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return source;
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}
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/**
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* Marks the present position in the stream. Subsequent calls to reset() will
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* reposition the stream to this point.
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*/
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public void mark()
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{
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mark = pos;
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}
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/**
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* Returns the current position of the reader.
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*
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* @return current position of the reader.
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*/
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public int pos()
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{
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return pos;
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}
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/**
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* Attempts to read a character from the current position. The caller must
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* ensure that the source string has the data available from the current
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* position.
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*
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* @return The character at the current position.
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* @throws StringIndexOutOfBoundsException If there is no more data
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* available to read.
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*/
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public char read()
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{
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if (pos >= length)
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{
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throw new StringIndexOutOfBoundsException();
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}
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return source.charAt(pos++);
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}
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/**
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* Attempts to read a substring of the specified length from the current
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* position. The caller must ensure that the requested length is within the
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* bounds i.e. the requested length from the current position should not
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* exceed the length of the source string.
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*
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* @param length
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* The number of characters to read.
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* @return The substring.
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* @throws StringIndexOutOfBoundsException If the length exceeds the
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* allowed length.
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*/
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public String read(final int length)
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{
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if (length > this.length || pos + length > this.length)
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{
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throw new StringIndexOutOfBoundsException();
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}
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final String substring = source.substring(pos, pos + length);
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pos += length;
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return substring;
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}
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/**
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* Returns the remaining length of the available data.
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*
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* @return remaining length.
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*/
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public int remaining()
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{
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return length - pos;
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}
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/**
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* Resets the stream to the most recent mark, or to the beginning of the
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* string if it has never been marked.
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*/
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public void reset()
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{
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pos = mark;
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}
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/**
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* Skips the whitespace characters and advances the reader to the next non
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* whitespace character.
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*
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* @return number of whitespace characters skipped.
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*/
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public int skipWhitespaces()
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{
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int skipped = 0;
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while (pos < length && source.charAt(pos) == ' ')
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{
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skipped++;
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pos++;
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}
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return skipped;
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}
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}
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