ohair@286: /*
alanb@368:  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
ohair@286:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ohair@286:  *
ohair@286:  * This code is free software; you can redistribute it and/or modify it
ohair@286:  * under the terms of the GNU General Public License version 2 only, as
ohair@286:  * published by the Free Software Foundation.  Oracle designates this
ohair@286:  * particular file as subject to the "Classpath" exception as provided
ohair@286:  * by Oracle in the LICENSE file that accompanied this code.
ohair@286:  *
ohair@286:  * This code is distributed in the hope that it will be useful, but WITHOUT
ohair@286:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ohair@286:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ohair@286:  * version 2 for more details (a copy is included in the LICENSE file that
ohair@286:  * accompanied this code).
ohair@286:  *
ohair@286:  * You should have received a copy of the GNU General Public License version
ohair@286:  * 2 along with this work; if not, write to the Free Software Foundation,
ohair@286:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ohair@286:  *
ohair@286:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
ohair@286:  * or visit www.oracle.com if you need additional information or have any
ohair@286:  * questions.
ohair@286:  */
ohair@286: 
ohair@286: package com.sun.xml.internal.messaging.saaj.util;
ohair@286: 
ohair@286: import java.io.*;
ohair@286: 
ohair@286: import javax.xml.transform.TransformerException;
ohair@286: 
ohair@286: /*
ohair@286:  * Class that parses the very first construct in the document i.e.
ohair@286:  *  <?xml ... ?>
ohair@286:  *
ohair@286:  * @author Panos Kougiouris (panos@acm.org)
ohair@286:  * @version
ohair@286:  */
ohair@286: 
ohair@286: public class XMLDeclarationParser {
ohair@286:     private String m_encoding;
ohair@286:     private PushbackReader m_pushbackReader;
ohair@286:     private boolean m_hasHeader; // preserve the case where no XML Header exists
ohair@286:     private String xmlDecl = null;
ohair@286:     static String gt16 = null;
ohair@286:     static String utf16Decl = null;
ohair@286:     static {
ohair@286:          try {
ohair@286:              gt16 = new String(">".getBytes("utf-16"));
ohair@286:              utf16Decl = new String("<?xml".getBytes("utf-16"));
ohair@286:          } catch (Exception e) {}
ohair@286:     }
ohair@286: 
ohair@286:     //---------------------------------------------------------------------
ohair@286: 
ohair@286:     public XMLDeclarationParser(PushbackReader pr)
ohair@286:     {
ohair@286:         m_pushbackReader = pr;
ohair@286:         m_encoding = "utf-8";
ohair@286:         m_hasHeader = false;
ohair@286:     }
ohair@286: 
ohair@286:     //---------------------------------------------------------------------
ohair@286:     public String getEncoding()
ohair@286:     {
ohair@286:         return m_encoding;
ohair@286:     }
ohair@286: 
ohair@286:     public String getXmlDeclaration() {
ohair@286:         return xmlDecl;
ohair@286:     }
ohair@286: 
ohair@286:     //---------------------------------------------------------------------
ohair@286: 
ohair@286:      public void parse()  throws TransformerException, IOException
ohair@286:      {
ohair@286:         int c = 0;
ohair@286:         int index = 0;
ohair@286:         char[] aChar = new char[65535];
ohair@286:         StringBuffer xmlDeclStr = new StringBuffer();
ohair@286:         while ((c = m_pushbackReader.read()) != -1) {
ohair@286:             aChar[index] = (char)c;
ohair@286:             xmlDeclStr.append((char)c);
ohair@286:             index++;
ohair@286:             if (c == '>') {
ohair@286:                 break;
ohair@286:             }
ohair@286:         }
ohair@286:         int len = index;
ohair@286: 
ohair@286:         String decl = xmlDeclStr.toString();
ohair@286:         boolean utf16 = false;
ohair@286:         boolean utf8 = false;
ohair@286: 
ohair@286:         int xmlIndex = decl.indexOf(utf16Decl);
ohair@286:         if (xmlIndex > -1) {
ohair@286:             utf16 = true;
ohair@286:         } else {
ohair@286:             xmlIndex = decl.indexOf("<?xml");
ohair@286:             if (xmlIndex > -1) {
ohair@286:                 utf8 = true;
ohair@286:             }
ohair@286:         }
ohair@286: 
ohair@286:         // no XML decl
ohair@286:         if (!utf16 && !utf8) {
ohair@286:             m_pushbackReader.unread(aChar, 0, len);
ohair@286:             return;
ohair@286:         }
ohair@286:         m_hasHeader = true;
ohair@286: 
ohair@286:         if (utf16) {
ohair@286:             xmlDecl = new String(decl.getBytes(), "utf-16");
ohair@286:             xmlDecl = xmlDecl.substring(xmlDecl.indexOf("<"));
ohair@286:         } else {
ohair@286:             xmlDecl = decl;
ohair@286:         }
ohair@286:         // do we want to check that there are no other characters preceeding <?xml
ohair@286:         if (xmlIndex != 0) {
ohair@286:             throw new IOException("Unexpected characters before XML declaration");
ohair@286:         }
ohair@286: 
ohair@286:         int versionIndex =  xmlDecl.indexOf("version");
ohair@286:         if (versionIndex == -1) {
ohair@286:             throw new IOException("Mandatory 'version' attribute Missing in XML declaration");
ohair@286:         }
ohair@286: 
ohair@286:         // now set
ohair@286:         int encodingIndex = xmlDecl.indexOf("encoding");
ohair@286:         if (encodingIndex == -1) {
ohair@286:             return;
ohair@286:         }
ohair@286: 
ohair@286:         if (versionIndex > encodingIndex) {
ohair@286:             throw new IOException("The 'version' attribute should preceed the 'encoding' attribute in an XML Declaration");
ohair@286:         }
ohair@286: 
ohair@286:         int stdAloneIndex = xmlDecl.indexOf("standalone");
ohair@286:         if ((stdAloneIndex > -1) && ((stdAloneIndex < versionIndex) || (stdAloneIndex < encodingIndex))) {
ohair@286:             throw new IOException("The 'standalone' attribute should be the last attribute in an XML Declaration");
ohair@286:         }
ohair@286: 
ohair@286:         int eqIndex = xmlDecl.indexOf("=", encodingIndex);
ohair@286:         if (eqIndex == -1) {
ohair@286:             throw new IOException("Missing '=' character after 'encoding' in XML declaration");
ohair@286:         }
ohair@286: 
ohair@286:         m_encoding = parseEncoding(xmlDecl, eqIndex);
ohair@286:         if(m_encoding.startsWith("\"")){
ohair@286:             m_encoding = m_encoding.substring(m_encoding.indexOf("\"")+1, m_encoding.lastIndexOf("\""));
ohair@286:         } else if(m_encoding.startsWith("\'")){
ohair@286:             m_encoding = m_encoding.substring(m_encoding.indexOf("\'")+1, m_encoding.lastIndexOf("\'"));
ohair@286:         }
ohair@286:      }
ohair@286: 
ohair@286:      //--------------------------------------------------------------------
ohair@286: 
ohair@286:     public void writeTo(Writer wr) throws IOException {
ohair@286:         if (!m_hasHeader) return;
ohair@286:         wr.write(xmlDecl.toString());
ohair@286:     }
ohair@286: 
ohair@286:     private String parseEncoding(String xmlDeclFinal, int eqIndex) throws IOException {
ohair@286:         java.util.StringTokenizer strTok = new java.util.StringTokenizer(
ohair@286:             xmlDeclFinal.substring(eqIndex + 1));
ohair@286:         if (strTok.hasMoreTokens()) {
ohair@286:             String encodingTok = strTok.nextToken();
ohair@286:             int indexofQ = encodingTok.indexOf("?");
ohair@286:             if (indexofQ > -1) {
ohair@286:                 return encodingTok.substring(0,indexofQ);
ohair@286:             } else {
ohair@286:                 return encodingTok;
ohair@286:             }
ohair@286:         } else {
ohair@286:             throw new IOException("Error parsing 'encoding' attribute in XML declaration");
ohair@286:         }
ohair@286:     }
ohair@286: 
ohair@286: }