com.aowagie.text.xml.simpleparser.SimpleXMLParser Maven / Gradle / Ivy
/*
* Copyright 2003 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/
*
* The code to recognize the encoding in this class and in the convenience class IanaEncodings was taken from Apache Xerces published under the following license:
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (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.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* Part of this code is based on the Quick-and-Dirty XML parser by Steven Brandt.
* The code for the Quick-and-Dirty parser was published in JavaWorld (java tip 128).
* Steven Brandt and JavaWorld gave permission to use the code for free.
* (Bruno Lowagie and Paulo Soares chose to use it under the MPL/LGPL in
* conformance with the rest of the code).
* The original code can be found on this url: http://www.javaworld.com/javatips/jw-javatip128_p.html.
* It was substantially refactored by Bruno Lowagie.
*
* The method 'private static String getEncodingName(byte[] b4)' was found
* in org.apache.xerces.impl.XMLEntityManager, originaly published by the
* Apache Software Foundation under the Apache Software License; now being
* used in iText under the MPL.
*/
package com.aowagie.text.xml.simpleparser;
import java.io.BufferedReader;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.Reader;
import java.nio.charset.StandardCharsets;
import java.util.HashMap;
import java.util.Stack;
/**
* A simple XML and HTML parser. This parser is, like the SAX parser,
* an event based parser, but with much less functionality.
*
* The parser can:
*
* - It recognizes the encoding used
*
- It recognizes all the elements' start tags and end tags
*
- It lists attributes, where attribute values can be enclosed in single or double quotes
*
- It recognizes the
<[CDATA[ ... ]]> construct
* - It recognizes the standard entities: &, <, >, ", and ', as well as numeric entities
*
- It maps lines ending in
\r\n and \r to \n on input, in accordance with the XML Specification, Section 2.11
*
*/
public final class SimpleXMLParser {
/** possible states */
private final static int UNKNOWN = 0;
private final static int TEXT = 1;
private final static int TAG_ENCOUNTERED = 2;
private final static int EXAMIN_TAG = 3;
private final static int TAG_EXAMINED = 4;
private final static int IN_CLOSETAG = 5;
private final static int SINGLE_TAG = 6;
private final static int CDATA = 7;
private final static int COMMENT = 8;
private final static int PI = 9;
private final static int ENTITY = 10;
private final static int QUOTE = 11;
private final static int ATTRIBUTE_KEY = 12;
private final static int ATTRIBUTE_EQUAL = 13;
private final static int ATTRIBUTE_VALUE = 14;
/** the state stack */
private final Stack stack;
/** The current character. */
private int character = 0;
/** The previous character. */
private int previousCharacter = -1;
/** the line we are currently reading */
private int lines = 1;
/** the column where the current character occurs */
private int columns = 0;
/** was the last character equivalent to a newline? */
private boolean eol = false;
/**
* A boolean indicating if the next character should be taken into account
* if it's a space character. When nospace is false, the previous character
* wasn't whitespace.
* @since 2.1.5
*/
private boolean nowhite = false;
/** the current state */
private int state;
/** Are we parsing HTML? */
private final boolean html;
/** current text (whatever is encountered between tags) */
private final StringBuffer text = new StringBuffer();
/** current entity (whatever is encountered between & and ;) */
private final StringBuffer entity = new StringBuffer();
/** current tagname */
private String tag = null;
/** current attributes */
private HashMap attributes = null;
/** The handler to which we are going to forward document content */
private final SimpleXMLDocHandler doc;
/** The handler to which we are going to forward comments. */
private final SimpleXMLDocHandlerComment comment;
/** Keeps track of the number of tags that are open. */
private int nested = 0;
/** the quote character that was used to open the quote. */
private int quoteCharacter = '"';
/** the attribute key. */
private String attributekey = null;
/** the attribute value. */
private String attributevalue = null;
/**
* Creates a Simple XML parser object.
* Call go(BufferedReader) immediately after creation.
*/
private SimpleXMLParser(final SimpleXMLDocHandler doc, final SimpleXMLDocHandlerComment comment, final boolean html) {
this.doc = doc;
this.comment = comment;
this.html = html;
this.stack = new Stack();
this.state = html ? TEXT : UNKNOWN;
}
/**
* Does the actual parsing. Perform this immediately
* after creating the parser object.
*/
private void go(final Reader r) throws IOException {
BufferedReader reader;
if (r instanceof BufferedReader) {
reader = (BufferedReader)r;
} else {
reader = new BufferedReader(r);
}
this.doc.startDocument();
while(true) {
// read a new character
if (this.previousCharacter == -1) {
this.character = reader.read();
}
// or re-examine the previous character
else {
this.character = this.previousCharacter;
this.previousCharacter = -1;
}
// the end of the file was reached
if (this.character == -1) {
if (this.html) {
if (this.html && this.state == TEXT) {
flush();
}
this.doc.endDocument();
} else {
throwException("Missing end tag");
}
return;
}
// dealing with \n and \r
if (this.character == '\n' && this.eol) {
this.eol = false;
continue;
} else if (this.eol) {
this.eol = false;
} else if (this.character == '\n') {
this.lines++;
this.columns = 0;
} else if (this.character == '\r') {
this.eol = true;
this.character = '\n';
this.lines++;
this.columns = 0;
} else {
this.columns++;
}
switch(this.state) {
// we are in an unknown state before there's actual content
case UNKNOWN:
if(this.character == '<') {
saveState(TEXT);
this.state = TAG_ENCOUNTERED;
}
break;
// we can encounter any content
case TEXT:
if(this.character == '<') {
flush();
saveState(this.state);
this.state = TAG_ENCOUNTERED;
} else if(this.character == '&') {
saveState(this.state);
this.entity.setLength(0);
this.state = ENTITY;
} else if (Character.isWhitespace((char)this.character)) {
if (this.nowhite) {
this.text.append((char)this.character);
}
this.nowhite = false;
} else {
this.text.append((char)this.character);
this.nowhite = true;
}
break;
// we have just seen a < and are wondering what we are looking at
// , , , etc.
case TAG_ENCOUNTERED:
initTag();
if(this.character == '/') {
this.state = IN_CLOSETAG;
} else if (this.character == '?') {
restoreState();
this.state = PI;
} else {
this.text.append((char)this.character);
this.state = EXAMIN_TAG;
}
break;
// we are processing something like this .
// It could still be a or something.
case EXAMIN_TAG:
if(this.character == '>') {
doTag();
processTag(true);
initTag();
this.state = restoreState();
} else if(this.character == '/') {
this.state = SINGLE_TAG;
} else if(this.character == '-' && this.text.toString().equals("!-")) {
flush();
this.state = COMMENT;
} else if(this.character == '[' && this.text.toString().equals("![CDATA")) {
flush();
this.state = CDATA;
} else if(this.character == 'E' && this.text.toString().equals("!DOCTYP")) {
flush();
this.state = PI;
} else if(Character.isWhitespace((char)this.character)) {
doTag();
this.state = TAG_EXAMINED;
} else {
this.text.append((char)this.character);
}
break;
// we know the name of the tag now.
case TAG_EXAMINED:
if(this.character == '>') {
processTag(true);
initTag();
this.state = restoreState();
} else if(this.character == '/') {
this.state = SINGLE_TAG;
} else if(Character.isWhitespace((char)this.character)) {
// empty
} else {
this.text.append((char)this.character);
this.state = ATTRIBUTE_KEY;
}
break;
// we are processing a closing tag: e.g.
case IN_CLOSETAG:
if(this.character == '>') {
doTag();
processTag(false);
if(!this.html && this.nested==0) {
return;
}
this.state = restoreState();
} else {
if (!Character.isWhitespace((char)this.character)) {
this.text.append((char)this.character);
}
}
break;
// we have just seen something like this: .
case SINGLE_TAG:
if(this.character != '>') {
throwException("Expected > for tag: <"+this.tag+"/>");
}
doTag();
processTag(true);
processTag(false);
initTag();
if(!this.html && this.nested==0) {
this.doc.endDocument();
return;
}
this.state = restoreState();
break;
// we are processing CDATA
case CDATA:
if(this.character == '>'
&& this.text.toString().endsWith("]]")) {
this.text.setLength(this.text.length()-2);
flush();
this.state = restoreState();
} else {
this.text.append((char)this.character);
}
break;
// we are processing a comment. We are inside
// the looking for the -->.
case COMMENT:
if(this.character == '>'
&& this.text.toString().endsWith("--")) {
this.text.setLength(this.text.length() - 2);
flush();
this.state = restoreState();
} else {
this.text.append((char)this.character);
}
break;
// We are inside one of these or one of these
case PI:
if(this.character == '>') {
this.state = restoreState();
if(this.state == TEXT) {
this.state = UNKNOWN;
}
}
break;
// we are processing an entity, e.g. <, », etc.
case ENTITY:
if(this.character == ';') {
this.state = restoreState();
final String cent = this.entity.toString();
this.entity.setLength(0);
final char ce = EntitiesToUnicode.decodeEntity(cent);
if (ce == '\0') {
this.text.append('&').append(cent).append(';');
} else {
this.text.append(ce);
}
} else if (this.character != '#' && (this.character < '0' || this.character > '9') && (this.character < 'a' || this.character > 'z')
&& (this.character < 'A' || this.character > 'Z') || this.entity.length() >= 7) {
this.state = restoreState();
this.previousCharacter = this.character;
this.text.append('&').append(this.entity.toString());
this.entity.setLength(0);
}
else {
this.entity.append((char)this.character);
}
break;
// We are processing the quoted right-hand side of an element's attribute.
case QUOTE:
if (this.html && this.quoteCharacter == ' ' && this.character == '>') {
flush();
processTag(true);
initTag();
this.state = restoreState();
}
else if (this.html && this.quoteCharacter == ' ' && Character.isWhitespace((char)this.character)) {
flush();
this.state = TAG_EXAMINED;
}
else if (this.html && this.quoteCharacter == ' ') {
this.text.append((char)this.character);
}
else if(this.character == this.quoteCharacter) {
flush();
this.state = TAG_EXAMINED;
} else if(" \r\n\u0009".indexOf(this.character)>=0) {
this.text.append(' ');
} else if(this.character == '&') {
saveState(this.state);
this.state = ENTITY;
this.entity.setLength(0);
} else {
this.text.append((char)this.character);
}
break;
case ATTRIBUTE_KEY:
if(Character.isWhitespace((char)this.character)) {
flush();
this.state = ATTRIBUTE_EQUAL;
} else if(this.character == '=') {
flush();
this.state = ATTRIBUTE_VALUE;
} else if (this.html && this.character == '>') {
this.text.setLength(0);
processTag(true);
initTag();
this.state = restoreState();
} else {
this.text.append((char)this.character);
}
break;
case ATTRIBUTE_EQUAL:
if(this.character == '=') {
this.state = ATTRIBUTE_VALUE;
} else if(Character.isWhitespace((char)this.character)) {
// empty
} else if (this.html && this.character == '>') {
this.text.setLength(0);
processTag(true);
initTag();
this.state = restoreState();
} else if (this.html && this.character == '/') {
flush();
this.state = SINGLE_TAG;
} else if (this.html) {
flush();
this.text.append((char)this.character);
this.state = ATTRIBUTE_KEY;
} else {
throwException("Error in attribute processing.");
}
break;
case ATTRIBUTE_VALUE:
if(this.character == '"' || this.character == '\'') {
this.quoteCharacter = this.character;
this.state = QUOTE;
} else if(Character.isWhitespace((char)this.character)) {
// empty
} else if (this.html && this.character == '>') {
flush();
processTag(true);
initTag();
this.state = restoreState();
} else if (this.html) {
this.text.append((char)this.character);
this.quoteCharacter = ' ';
this.state = QUOTE;
} else {
throwException("Error in attribute processing");
}
break;
}
}
}
/**
* Gets a state from the stack
* @return the previous state
*/
private int restoreState() {
if(!this.stack.empty()) {
return ((Integer)this.stack.pop()).intValue();
} else {
return UNKNOWN;
}
}
/**
* Adds a state to the stack.
* @param s a state to add to the stack
*/
private void saveState(final int s) {
this.stack.push(Integer.valueOf(s));
}
/**
* Flushes the text that is currently in the buffer.
* The text can be ignored, added to the document
* as content or as comment,... depending on the current state.
*/
private void flush() {
switch(this.state){
case TEXT:
case CDATA:
if(this.text.length() > 0) {
this.doc.text(this.text.toString());
}
break;
case COMMENT:
if (this.comment != null) {
this.comment.comment(this.text.toString());
}
break;
case ATTRIBUTE_KEY:
this.attributekey = this.text.toString();
if (this.html) {
this.attributekey = this.attributekey.toLowerCase();
}
break;
case QUOTE:
case ATTRIBUTE_VALUE:
this.attributevalue = this.text.toString();
this.attributes.put(this.attributekey,this.attributevalue);
break;
default:
// do nothing
}
this.text.setLength(0);
}
/**
* Initialized the tag name and attributes.
*/
private void initTag() {
this.tag = null;
this.attributes = new HashMap();
}
/** Sets the name of the tag. */
private void doTag() {
if(this.tag == null) {
this.tag = this.text.toString();
}
if (this.html) {
this.tag = this.tag.toLowerCase();
}
this.text.setLength(0);
}
/**
* processes the tag.
* @param start if true we are dealing with a tag that has just been opened; if false we are closing a tag.
*/
private void processTag(final boolean start) {
if (start) {
this.nested++;
this.doc.startElement(this.tag,this.attributes);
}
else {
this.nested--;
this.doc.endElement(this.tag);
}
}
/** Throws an exception */
private void throwException(final String s) throws IOException {
throw new IOException(s+" near line " + this.lines + ", column " + this.columns);
}
/**
* Parses the XML document firing the events to the handler.
* @param doc the document handler
* @param r the document. The encoding is already resolved. The reader is not closed
* @throws IOException on error
*/
private static void parse(final SimpleXMLDocHandler doc, final SimpleXMLDocHandlerComment comment, final Reader r, final boolean html) throws IOException {
final SimpleXMLParser parser = new SimpleXMLParser(doc, comment, html);
parser.go(r);
}
/**
* Parses the XML document firing the events to the handler.
* @param doc the document handler
* @param in the document. The encoding is deduced from the stream. The stream is not closed
* @throws IOException on error
*/
public static void parse(final SimpleXMLDocHandler doc, final InputStream in) throws IOException {
final byte b4[] = new byte[4];
final int count = in.read(b4);
if (count != 4) {
throw new IOException("Insufficient length.");
}
String encoding = getEncodingName(b4);
String decl = null;
if (encoding.equals("UTF-8")) {
final StringBuffer sb = new StringBuffer();
int c;
while ((c = in.read()) != -1) {
if (c == '>') {
break;
}
sb.append((char)c);
}
decl = sb.toString();
}
else if (encoding.equals("CP037")) {
final ByteArrayOutputStream bi = new ByteArrayOutputStream();
int c;
while ((c = in.read()) != -1) {
if (c == 0x6e) {
break;
}
bi.write(c);
}
decl = new String(bi.toByteArray(), "CP037");
}
if (decl != null) {
decl = getDeclaredEncoding(decl);
if (decl != null) {
encoding = decl;
}
}
parse(doc, new InputStreamReader(in, IanaEncodings.getJavaEncoding(encoding)));
}
private static String getDeclaredEncoding(final String decl) {
if (decl == null) {
return null;
}
final int idx = decl.indexOf("encoding");
if (idx < 0) {
return null;
}
final int idx1 = decl.indexOf('"', idx);
final int idx2 = decl.indexOf('\'', idx);
if (idx1 == idx2) {
return null;
}
if (idx1 < 0 && idx2 > 0 || idx2 > 0 && idx2 < idx1) {
final int idx3 = decl.indexOf('\'', idx2 + 1);
if (idx3 < 0) {
return null;
}
return decl.substring(idx2 + 1, idx3);
}
if (idx2 < 0 && idx1 > 0 || idx1 > 0 && idx1 < idx2) {
final int idx3 = decl.indexOf('"', idx1 + 1);
if (idx3 < 0) {
return null;
}
return decl.substring(idx1 + 1, idx3);
}
return null;
}
private static void parse(final SimpleXMLDocHandler doc,final Reader r) throws IOException {
parse(doc, null, r, false);
}
/**
* Escapes a string with the appropriated XML codes.
* @param s the string to be escaped
* @param onlyASCII codes above 127 will always be escaped with &#nn; if true
* @return the escaped string
*/
public static String escapeXML(final String s, final boolean onlyASCII) {
final char cc[] = s.toCharArray();
final int len = cc.length;
final StringBuffer sb = new StringBuffer();
for (int k = 0; k < len; ++k) {
final int c = cc[k];
switch (c) {
case '<':
sb.append("<");
break;
case '>':
sb.append(">");
break;
case '&':
sb.append("&");
break;
case '"':
sb.append(""");
break;
case '\'':
sb.append("'");
break;
default:
if (c == 0x9 || c == 0xA || c == 0xD
|| c >= 0x20 && c <= 0xD7FF
|| c >= 0xE000 && c <= 0xFFFD
|| c >= 0x10000 && c <= 0x10FFFF) {
if (onlyASCII && c > 127) {
sb.append("&#").append(c).append(';');
} else {
sb.append((char)c);
}
}
}
}
return sb.toString();
}
/**
* Returns the IANA encoding name that is auto-detected from
* the bytes specified, with the endian-ness of that encoding where appropriate.
* (method found in org.apache.xerces.impl.XMLEntityManager, originally published
* by the Apache Software Foundation under the Apache Software License; now being
* used in iText under the MPL)
* @param b4 The first four bytes of the input.
* @return an IANA-encoding string
*/
private static String getEncodingName(final byte[] b4) {
// UTF-16, with BOM
final int b0 = b4[0] & 0xFF;
final int b1 = b4[1] & 0xFF;
if (b0 == 0xFE && b1 == 0xFF) {
// UTF-16, big-endian
return "UTF-16BE";
}
if (b0 == 0xFF && b1 == 0xFE) {
// UTF-16, little-endian
return "UTF-16LE";
}
// UTF-8 with a BOM
final int b2 = b4[2] & 0xFF;
if (b0 == 0xEF && b1 == 0xBB && b2 == 0xBF) {
return StandardCharsets.UTF_8.name();
}
// other encodings
final int b3 = b4[3] & 0xFF;
if (b0 == 0x00 && b1 == 0x00 && b2 == 0x00 && b3 == 0x3C) {
// UCS-4, big endian (1234)
return "ISO-10646-UCS-4";
}
if (b0 == 0x3C && b1 == 0x00 && b2 == 0x00 && b3 == 0x00) {
// UCS-4, little endian (4321)
return "ISO-10646-UCS-4";
}
if (b0 == 0x00 && b1 == 0x00 && b2 == 0x3C && b3 == 0x00) {
// UCS-4, unusual octet order (2143)
// REVISIT: What should this be?
return "ISO-10646-UCS-4";
}
if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x00) {
// UCS-4, unusual octet order (3412)
// REVISIT: What should this be?
return "ISO-10646-UCS-4";
}
if (b0 == 0x00 && b1 == 0x3C && b2 == 0x00 && b3 == 0x3F) {
// UTF-16, big-endian, no BOM
// (or could turn out to be UCS-2...
// REVISIT: What should this be?
return "UTF-16BE";
}
if (b0 == 0x3C && b1 == 0x00 && b2 == 0x3F && b3 == 0x00) {
// UTF-16, little-endian, no BOM
// (or could turn out to be UCS-2...
return "UTF-16LE";
}
if (b0 == 0x4C && b1 == 0x6F && b2 == 0xA7 && b3 == 0x94) {
// EBCDIC
// a la xerces1, return CP037 instead of EBCDIC here
return "CP037";
}
// default encoding
return StandardCharsets.UTF_8.name();
}
}