/* eXist Native XML Database
* Copyright (C) 2000-03, Wolfgang M. Meier (wolfgang@exist-db.org)
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) 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.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Id$
*/
package org.exist.util.serializer;
import java.io.IOException;
import java.io.Writer;
import java.util.Arrays;
import java.util.Properties;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.TransformerException;
import org.exist.dom.QName;
import org.exist.util.XMLString;
import org.exist.util.serializer.encodings.CharacterSet;
/**
* Write XML to a writer. This class defines methods similar to SAX. It deals
* with opening and closing tags, writing attributes and so on.
*
* @author wolf
*/
public class XMLWriter {
private final static IllegalStateException EX_CHARSET_NULL = new IllegalStateException("Charset should never be null!");
protected final static Properties defaultProperties = new Properties();
static {
defaultProperties.setProperty(OutputKeys.OMIT_XML_DECLARATION, "no");
}
protected Writer writer = null;
protected CharacterSet charSet = null;
protected boolean tagIsOpen = false;
protected boolean tagIsEmpty = true;
protected boolean declarationWritten = false;
protected boolean doctypeWritten = false;
protected Properties outputProperties;
private char[] charref = new char[10];
private static boolean[] textSpecialChars;
private static boolean[] attrSpecialChars;
private String defaultNamespace = "";
static {
textSpecialChars = new boolean[128];
Arrays.fill(textSpecialChars, false);
textSpecialChars['<'] = true;
textSpecialChars['>'] = true;
// textSpecialChars['\r'] = true;
textSpecialChars['&'] = true;
attrSpecialChars = new boolean[128];
Arrays.fill(attrSpecialChars, false);
attrSpecialChars['<'] = true;
attrSpecialChars['>'] = true;
attrSpecialChars['\r'] = true;
attrSpecialChars['\n'] = true;
attrSpecialChars['\t'] = true;
attrSpecialChars['&'] = true;
attrSpecialChars['"'] = true;
}
public XMLWriter() {
charSet = CharacterSet.getCharacterSet("UTF-8");
if(charSet == null) {
throw EX_CHARSET_NULL;
}
}
public XMLWriter(final Writer writer) {
this();
this.writer = writer;
}
/**
* Set the output properties.
*
* @param properties outputProperties
*/
public void setOutputProperties(final Properties properties) {
if(properties == null) {
outputProperties = defaultProperties;
} else {
outputProperties = properties;
}
final String encoding = outputProperties.getProperty(OutputKeys.ENCODING, "UTF-8");
charSet = CharacterSet.getCharacterSet(encoding);
if(charSet == null) {
throw EX_CHARSET_NULL;
}
}
protected void reset() {
writer = null;
resetObjectState();
}
protected void resetObjectState() {
tagIsOpen = false;
tagIsEmpty = true;
declarationWritten = false;
doctypeWritten = false;
defaultNamespace = "";
}
/**
* Set a new writer. Calling this method will reset the state of the object.
*
* @param writer
*/
public void setWriter(final Writer writer) {
this.writer = writer;
resetObjectState();
}
protected Writer getWriter() {
return writer;
}
public String getDefaultNamespace() {
return defaultNamespace.isEmpty() ? null : defaultNamespace;
}
public void setDefaultNamespace(final String namespace) {
defaultNamespace = namespace == null ? "" : namespace;
}
public void startDocument() throws TransformerException {
resetObjectState();
}
public void endDocument() throws TransformerException {
}
public void startElement(final String namespaceUri, final String localName, final String qname) throws TransformerException {
if(!declarationWritten) {
writeDeclaration();
}
if(!doctypeWritten) {
writeDoctype(qname);
}
try {
if(tagIsOpen) {
closeStartTag(false);
}
writer.write('<');
writer.write(qname);
tagIsOpen = true;
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void startElement(final QName qname) throws TransformerException {
if(!declarationWritten) {
writeDeclaration();
}
if(!doctypeWritten) {
writeDoctype(qname.getStringValue());
}
try {
if(tagIsOpen) {
closeStartTag(false);
}
writer.write('<');
if(qname.getPrefix() != null && qname.getPrefix().length() > 0) {
writer.write(qname.getPrefix());
writer.write(':');
}
writer.write(qname.getLocalPart());
tagIsOpen = true;
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void endElement(final String namespaceURI, final String localName, final String qname) throws TransformerException {
try {
if (tagIsOpen) {
closeStartTag(true);
} else {
writer.write("</");
writer.write(qname);
writer.write('>');
}
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void endElement(final QName qname) throws TransformerException {
try {
if(tagIsOpen) {
closeStartTag(true);
} else {
writer.write("</");
if(qname.getPrefix() != null && qname.getPrefix().length() > 0) {
writer.write(qname.getPrefix());
writer.write(':');
}
writer.write(qname.getLocalPart());
writer.write('>');
}
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void namespace(final String prefix, final String nsURI) throws TransformerException {
if((nsURI == null) && (prefix == null || prefix.length() == 0)) {
return;
}
try {
if(!tagIsOpen) {
throw new TransformerException("Found a namespace declaration outside an element");
}
if(prefix != null && prefix.length() > 0) {
writer.write(' ');
writer.write("xmlns");
writer.write(':');
writer.write(prefix);
writer.write("=\"");
writeChars(nsURI, true);
writer.write('"');
} else {
if(defaultNamespace.equals(nsURI)) {
return;
}
writer.write(' ');
writer.write("xmlns");
writer.write("=\"");
writeChars(nsURI, true);
writer.write('"');
defaultNamespace= nsURI;
}
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void attribute(String qname, String value) throws TransformerException {
try {
if(!tagIsOpen) {
characters(value);
return;
// throw new TransformerException("Found an attribute outside an
// element");
}
writer.write(' ');
writer.write(qname);
writer.write("=\"");
writeChars(value, true);
writer.write('"');
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void attribute(final QName qname, final String value) throws TransformerException {
try {
if(!tagIsOpen) {
characters(value);
return;
// throw new TransformerException("Found an attribute outside an
// element");
}
writer.write(' ');
if(qname.getPrefix() != null && qname.getPrefix().length() > 0) {
writer.write(qname.getPrefix());
writer.write(':');
}
writer.write(qname.getLocalPart());
writer.write("=\"");
writeChars(value, true);
writer.write('"');
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void characters(final CharSequence chars) throws TransformerException {
if(!declarationWritten) {
writeDeclaration();
}
try {
if(tagIsOpen) {
closeStartTag(false);
}
writeChars(chars, false);
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void characters(final char[] ch, final int start, final int len) throws TransformerException {
if(!declarationWritten) {
writeDeclaration();
}
final XMLString s = new XMLString(ch, start, len);
characters(s);
s.release();
}
public void processingInstruction(final String target, final String data) throws TransformerException {
if(!declarationWritten) {
writeDeclaration();
}
try {
if(tagIsOpen) {
closeStartTag(false);
}
writer.write("<?");
writer.write(target);
if(data != null && data.length() > 0) {
writer.write(' ');
writer.write(data);
}
writer.write("?>");
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void comment(final CharSequence data) throws TransformerException {
if (!declarationWritten) {
writeDeclaration();
}
try {
if(tagIsOpen) {
closeStartTag(false);
}
writer.write("<!--");
writer.write(data.toString());
writer.write("-->");
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void cdataSection(final char[] ch, final int start, final int len) throws TransformerException {
if(tagIsOpen) {
closeStartTag(false);
}
try {
writer.write("<![CDATA[");
writer.write(ch, start, len);
writer.write("]]>");
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
public void documentType(final String name, final String publicId, final String systemId) throws TransformerException {
if(!declarationWritten) {
writeDeclaration();
}
//if(publicId == null && systemId == null)
// return;
try {
writer.write("<!DOCTYPE ");
writer.write(name);
if(publicId != null) {
//writer.write(" PUBLIC \"" + publicId + "\"");
writer.write(" PUBLIC \"" + publicId.replaceAll(" ", " ") + "\""); //workaround for XHTML doctype, declare does not allow spaces so use instead and then replace each with a space here - Adam
}
if(systemId != null) {
if(publicId == null) {
writer.write(" SYSTEM");
}
writer.write(" \"" + systemId + "\"");
}
writer.write(">");
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
doctypeWritten = true;
}
protected void closeStartTag(final boolean isEmpty) throws TransformerException {
try {
if(tagIsOpen) {
if(isEmpty) {
writer.write("/>");
} else {
writer.write('>');
}
tagIsOpen = false;
}
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
protected void writeDeclaration() throws TransformerException {
if(declarationWritten) {
return;
}
if(outputProperties == null) {
outputProperties = defaultProperties;
}
declarationWritten = true;
final String omitXmlDecl = outputProperties.getProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");
if("no".equals(omitXmlDecl)) {
final String version = outputProperties.getProperty(OutputKeys.VERSION, "1.0");
final String standalone = outputProperties.getProperty(OutputKeys.STANDALONE);
final String encoding = outputProperties.getProperty(OutputKeys.ENCODING, "UTF-8");
try {
writer.write("<?xml version=\"");
writer.write(version);
writer.write("\" encoding=\"");
writer.write(encoding);
writer.write('"');
if(standalone != null) {
writer.write(" standalone=\"");
writer.write(standalone);
writer.write('"');
}
writer.write("?>\n");
} catch(final IOException ioe) {
throw new TransformerException(ioe.getMessage(), ioe);
}
}
}
protected void writeDoctype(final String rootElement) throws TransformerException {
if(doctypeWritten) {
return;
}
final String publicId = outputProperties.getProperty(OutputKeys.DOCTYPE_PUBLIC);
final String systemId = outputProperties.getProperty(OutputKeys.DOCTYPE_SYSTEM);
if(publicId != null || systemId != null) {
documentType(rootElement, publicId, systemId);
}
doctypeWritten = true;
}
protected boolean needsEscape(final char ch) {
return true;
}
protected void writeChars(final CharSequence s, final boolean inAttribute) throws IOException {
final boolean[] specialChars = inAttribute ? attrSpecialChars : textSpecialChars;
char ch = 0;
final int len = s.length();
int pos = 0, i;
while(pos < len) {
i = pos;
while(i < len) {
ch = s.charAt(i);
if(ch < 128) {
if(specialChars[ch]) {
break;
} else {
i++;
}
} else if(!charSet.inCharacterSet(ch)) {
break;
} else {
i++;
}
}
writeCharSeq(s, pos, i);
// writer.write(s.subSequence(pos, i).toString());
if (i >= len) {
return;
}
if(needsEscape(ch)) {
switch(ch) {
case '<':
writer.write("<");
break;
case '>':
writer.write(">");
break;
case '&':
writer.write("&");
break;
case '\r':
writer.write("
");
break;
case '\n':
writer.write("
");
break;
case '\t':
writer.write(" ");
break;
case '"':
writer.write(""");
break;
default:
writeCharacterReference(ch);
}
} else {
writer.write(ch);
}
pos = ++i;
}
}
private void writeCharSeq(final CharSequence ch, final int start, final int end) throws IOException {
for(int i = start; i < end; i++) {
writer.write(ch.charAt(i));
}
}
protected void writeCharacterReference(final char charval) throws IOException {
int o = 0;
charref[o++] = '&';
charref[o++] = '#';
charref[o++] = 'x';
final String code = Integer.toHexString(charval);
final int len = code.length();
for(int k = 0; k < len; k++) {
charref[o++] = code.charAt(k);
}
charref[o++] = ';';
writer.write(charref, 0, o);
}
}