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iText, a free Java-PDF library
/*
* $Id: PRTokeniser.java 2517 2006-12-28 19:41:02Z psoares33 $
*
* Copyright 2001, 2002 by Paulo Soares.
*
* The contents of this file are subject to the Mozilla Public License Version 1.1
* (the "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the License.
*
* The Original Code is 'iText, a free JAVA-PDF library'.
*
* The Initial Developer of the Original Code is Bruno Lowagie. Portions created by
* the Initial Developer are Copyright (C) 1999, 2000, 2001, 2002 by Bruno Lowagie.
* All Rights Reserved.
* Co-Developer of the code is Paulo Soares. Portions created by the Co-Developer
* are Copyright (C) 2000, 2001, 2002 by Paulo Soares. All Rights Reserved.
*
* Contributor(s): all the names of the contributors are added in the source code
* where applicable.
*
* Alternatively, the contents of this file may be used under the terms of the
* LGPL license (the "GNU LIBRARY GENERAL PUBLIC LICENSE"), in which case the
* provisions of LGPL are applicable instead of those above. If you wish to
* allow use of your version of this file only under the terms of the LGPL
* License and not to allow others to use your version of this file under
* the MPL, indicate your decision by deleting the provisions above and
* replace them with the notice and other provisions required by the LGPL.
* If you do not delete the provisions above, a recipient may use your version
* of this file under either the MPL or the GNU LIBRARY GENERAL PUBLIC LICENSE.
*
* This library is free software; you can redistribute it and/or modify it
* under the terms of the MPL as stated above or under the terms of the GNU
* Library General Public License as published by the Free Software Foundation;
* either version 2 of the License, or any later version.
*
* This library 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 Library general Public License for more
* details.
*
* If you didn't download this code from the following link, you should check if
* you aren't using an obsolete version:
* http://www.lowagie.com/iText/
*/
package com.lowagie.text.pdf;
import java.io.IOException;
/**
*
* @author Paulo Soares ([email protected])
*/
public class PRTokeniser {
public static final int TK_NUMBER = 1;
public static final int TK_STRING = 2;
public static final int TK_NAME = 3;
public static final int TK_COMMENT = 4;
public static final int TK_START_ARRAY = 5;
public static final int TK_END_ARRAY = 6;
public static final int TK_START_DIC = 7;
public static final int TK_END_DIC = 8;
public static final int TK_REF = 9;
public static final int TK_OTHER = 10;
public static final boolean delims[] = {
true, true, false, false, false, false, false, false, false, false,
true, true, false, true, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, true, false, false, false, false, true, false,
false, true, true, false, false, false, false, false, true, false,
false, false, false, false, false, false, false, false, false, false,
false, true, false, true, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, true, false, true, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false, false, false, false,
false, false, false, false, false, false, false};
static final String EMPTY = "";
protected RandomAccessFileOrArray file;
protected int type;
protected String stringValue;
protected int reference;
protected int generation;
protected boolean hexString;
public PRTokeniser(String filename) throws IOException {
file = new RandomAccessFileOrArray(filename);
}
public PRTokeniser(byte pdfIn[]) {
file = new RandomAccessFileOrArray(pdfIn);
}
public PRTokeniser(RandomAccessFileOrArray file) {
this.file = file;
}
public void seek(int pos) throws IOException {
file.seek(pos);
}
public int getFilePointer() throws IOException {
return file.getFilePointer();
}
public void close() throws IOException {
file.close();
}
public int length() throws IOException {
return file.length();
}
public int read() throws IOException {
return file.read();
}
public RandomAccessFileOrArray getSafeFile() {
return new RandomAccessFileOrArray(file);
}
public RandomAccessFileOrArray getFile() {
return file;
}
public String readString(int size) throws IOException {
StringBuffer buf = new StringBuffer();
int ch;
while ((size--) > 0) {
ch = file.read();
if (ch == -1)
break;
buf.append((char)ch);
}
return buf.toString();
}
public static final boolean isWhitespace(int ch) {
return (ch == 0 || ch == 9 || ch == 10 || ch == 12 || ch == 13 || ch == 32);
}
public static final boolean isDelimiter(int ch) {
return (ch == '(' || ch == ')' || ch == '<' || ch == '>' || ch == '[' || ch == ']' || ch == '/' || ch == '%');
}
public static final boolean isDelimiterWhitespace(int ch) {
return delims[ch + 1];
}
public int getTokenType() {
return type;
}
public String getStringValue() {
return stringValue;
}
public int getReference() {
return reference;
}
public int getGeneration() {
return generation;
}
public void backOnePosition(int ch) {
if (ch != -1)
file.pushBack((byte)ch);
}
public void throwError(String error) throws IOException {
throw new IOException(error + " at file pointer " + file.getFilePointer());
}
public char checkPdfHeader() throws IOException {
file.setStartOffset(0);
String str = readString(1024);
int idx = str.indexOf("%PDF-");
if (idx < 0)
throw new IOException("PDF header signature not found.");
file.setStartOffset(idx);
return str.charAt(idx + 7);
}
public void checkFdfHeader() throws IOException {
file.setStartOffset(0);
String str = readString(1024);
int idx = str.indexOf("%FDF-1.2");
if (idx < 0)
throw new IOException("FDF header signature not found.");
file.setStartOffset(idx);
}
public int getStartxref() throws IOException {
int size = Math.min(1024, file.length());
int pos = file.length() - size;
file.seek(pos);
String str = readString(1024);
int idx = str.lastIndexOf("startxref");
if (idx < 0)
throw new IOException("PDF startxref not found.");
return pos + idx;
}
public static int getHex(int v) {
if (v >= '0' && v <= '9')
return v - '0';
if (v >= 'A' && v <= 'F')
return v - 'A' + 10;
if (v >= 'a' && v <= 'f')
return v - 'a' + 10;
return -1;
}
public void nextValidToken() throws IOException {
int level = 0;
String n1 = null;
String n2 = null;
int ptr = 0;
while (nextToken()) {
if (type == TK_COMMENT)
continue;
switch (level) {
case 0:
{
if (type != TK_NUMBER)
return;
ptr = file.getFilePointer();
n1 = stringValue;
++level;
break;
}
case 1:
{
if (type != TK_NUMBER) {
file.seek(ptr);
type = TK_NUMBER;
stringValue = n1;
return;
}
n2 = stringValue;
++level;
break;
}
default:
{
if (type != TK_OTHER || !stringValue.equals("R")) {
file.seek(ptr);
type = TK_NUMBER;
stringValue = n1;
return;
}
type = TK_REF;
reference = Integer.parseInt(n1);
generation = Integer.parseInt(n2);
return;
}
}
}
throwError("Unexpected end of file");
}
public boolean nextToken() throws IOException {
StringBuffer outBuf = null;
stringValue = EMPTY;
int ch = 0;
do {
ch = file.read();
} while (ch != -1 && isWhitespace(ch));
if (ch == -1)
return false;
switch (ch) {
case '[':
type = TK_START_ARRAY;
break;
case ']':
type = TK_END_ARRAY;
break;
case '/':
{
outBuf = new StringBuffer();
type = TK_NAME;
while (true) {
ch = file.read();
if (delims[ch + 1])
break;
if (ch == '#') {
ch = (getHex(file.read()) << 4) + getHex(file.read());
}
outBuf.append((char)ch);
}
backOnePosition(ch);
break;
}
case '>':
ch = file.read();
if (ch != '>')
throwError("'>' not expected");
type = TK_END_DIC;
break;
case '<':
{
int v1 = file.read();
if (v1 == '<') {
type = TK_START_DIC;
break;
}
outBuf = new StringBuffer();
type = TK_STRING;
hexString = true;
int v2 = 0;
while (true) {
while (isWhitespace(v1))
v1 = file.read();
if (v1 == '>')
break;
v1 = getHex(v1);
if (v1 < 0)
break;
v2 = file.read();
while (isWhitespace(v2))
v2 = file.read();
if (v2 == '>') {
ch = v1 << 4;
outBuf.append((char)ch);
break;
}
v2 = getHex(v2);
if (v2 < 0)
break;
ch = (v1 << 4) + v2;
outBuf.append((char)ch);
v1 = file.read();
}
if (v1 < 0 || v2 < 0)
throwError("Error reading string");
break;
}
case '%':
type = TK_COMMENT;
do {
ch = file.read();
} while (ch != -1 && ch != '\r' && ch != '\n');
break;
case '(':
{
outBuf = new StringBuffer();
type = TK_STRING;
hexString = false;
int nesting = 0;
while (true) {
ch = file.read();
if (ch == -1)
break;
if (ch == '(') {
++nesting;
}
else if (ch == ')') {
--nesting;
}
else if (ch == '\\') {
boolean lineBreak = false;
ch = file.read();
switch (ch) {
case 'n':
ch = '\n';
break;
case 'r':
ch = '\r';
break;
case 't':
ch = '\t';
break;
case 'b':
ch = '\b';
break;
case 'f':
ch = '\f';
break;
case '(':
case ')':
case '\\':
break;
case '\r':
lineBreak = true;
ch = file.read();
if (ch != '\n')
backOnePosition(ch);
break;
case '\n':
lineBreak = true;
break;
default:
{
if (ch < '0' || ch > '7') {
break;
}
int octal = ch - '0';
ch = file.read();
if (ch < '0' || ch > '7') {
backOnePosition(ch);
ch = octal;
break;
}
octal = (octal << 3) + ch - '0';
ch = file.read();
if (ch < '0' || ch > '7') {
backOnePosition(ch);
ch = octal;
break;
}
octal = (octal << 3) + ch - '0';
ch = octal & 0xff;
break;
}
}
if (lineBreak)
continue;
if (ch < 0)
break;
}
else if (ch == '\r') {
ch = file.read();
if (ch < 0)
break;
if (ch != '\n') {
backOnePosition(ch);
ch = '\n';
}
}
if (nesting == -1)
break;
outBuf.append((char)ch);
}
if (ch == -1)
throwError("Error reading string");
break;
}
default:
{
outBuf = new StringBuffer();
if (ch == '-' || ch == '+' || ch == '.' || (ch >= '0' && ch <= '9')) {
type = TK_NUMBER;
do {
outBuf.append((char)ch);
ch = file.read();
} while (ch != -1 && ((ch >= '0' && ch <= '9') || ch == '.'));
}
else {
type = TK_OTHER;
do {
outBuf.append((char)ch);
ch = file.read();
} while (!delims[ch + 1]);
}
backOnePosition(ch);
break;
}
}
if (outBuf != null)
stringValue = outBuf.toString();
return true;
}
public int intValue() {
return Integer.parseInt(stringValue);
}
public boolean readLineSegment(byte input[]) throws IOException {
int c = -1;
boolean eol = false;
int ptr = 0;
int len = input.length;
// ssteward, pdftk-1.10, 040922:
// skip initial whitespace; added this because PdfReader.rebuildXref()
// assumes that line provided by readLineSegment does not have init. whitespace;
if ( ptr < len ) {
while ( isWhitespace( (c = read()) ) );
}
while ( !eol && ptr < len ) {
switch (c) {
case -1:
case '\n':
eol = true;
break;
case '\r':
eol = true;
int cur = getFilePointer();
if ((read()) != '\n') {
seek(cur);
}
break;
default:
input[ptr++] = (byte)c;
break;
}
// break loop? do it before we read() again
if( eol || len <= ptr ) {
break;
}
else {
c = read();
}
}
if (ptr >= len) {
eol = false;
while (!eol) {
switch (c = read()) {
case -1:
case '\n':
eol = true;
break;
case '\r':
eol = true;
int cur = getFilePointer();
if ((read()) != '\n') {
seek(cur);
}
break;
}
}
}
if ((c == -1) && (ptr == 0)) {
return false;
}
if (ptr + 2 <= len) {
input[ptr++] = (byte)' ';
input[ptr] = (byte)'X';
}
return true;
}
public static int[] checkObjectStart(byte line[]) {
try {
PRTokeniser tk = new PRTokeniser(line);
int num = 0;
int gen = 0;
if (!tk.nextToken() || tk.getTokenType() != TK_NUMBER)
return null;
num = tk.intValue();
if (!tk.nextToken() || tk.getTokenType() != TK_NUMBER)
return null;
gen = tk.intValue();
if (!tk.nextToken())
return null;
if (!tk.getStringValue().equals("obj"))
return null;
return new int[]{num, gen};
}
catch (Exception ioe) {
// empty on purpose
}
return null;
}
public boolean isHexString() {
return this.hexString;
}
}