1 /*
   2  * Copyright (c) 1997, 2012, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package com.sun.tools.internal.ws.wsdl.parser;
  27 
  28 import com.sun.xml.internal.bind.WhiteSpaceProcessor;
  29 import org.xml.sax.*;
  30 import org.xml.sax.helpers.XMLFilterImpl;
  31 
  32 /**
  33  * Strips ignorable whitespace from SAX event stream.
  34  *
  35  * <p>
  36  * This filter works only when the event stream doesn't
  37  * contain any mixed content.
  38  *
  39  * @author
  40  *     Kohsuke Kawaguchi (kohsuke.kawaguchi@sun.com)
  41  *     Vivek Pandey
  42  */
  43 class WhitespaceStripper extends XMLFilterImpl {
  44 
  45     private int state = 0;
  46 
  47     private char[] buf = new char[1024];
  48     private int bufLen = 0;
  49 
  50     private static final int AFTER_START_ELEMENT = 1;
  51     private static final int AFTER_END_ELEMENT = 2;
  52 
  53     public WhitespaceStripper(XMLReader reader) {
  54         setParent(reader);
  55     }
  56 
  57     public WhitespaceStripper(ContentHandler handler, ErrorHandler eh, EntityResolver er) {
  58         setContentHandler(handler);
  59         if(eh!=null)    setErrorHandler(eh);
  60         if(er!=null)    setEntityResolver(er);
  61     }
  62 
  63     public void characters(char[] ch, int start, int length) throws SAXException {
  64         switch(state) {
  65         case AFTER_START_ELEMENT:
  66             // we have to store the characters here, even if it consists entirely
  67             // of whitespaces. This is because successive characters event might
  68             // include non-whitespace char, in which case all the whitespaces in
  69             // this event may suddenly become significant.
  70             if( bufLen+length>buf.length ) {
  71                 // reallocate buffer
  72                 char[] newBuf = new char[Math.max(bufLen+length,buf.length*2)];
  73                 System.arraycopy(buf,0,newBuf,0,bufLen);
  74                 buf = newBuf;
  75             }
  76             System.arraycopy(ch,start,buf,bufLen,length);
  77             bufLen += length;
  78             break;
  79         case AFTER_END_ELEMENT:
  80             // check if this is ignorable.
  81             int len = start+length;
  82             for( int i=start; i<len; i++ )
  83                 if( !WhiteSpaceProcessor.isWhiteSpace(ch[i]) ) {
  84                     super.characters(ch, start, length);
  85                     return;
  86                 }
  87             // if it's entirely whitespace, ignore it.
  88             break;
  89         }
  90     }
  91 
  92     public void startElement(String uri, String localName, String qName, Attributes atts) throws SAXException {
  93         processPendingText();
  94         super.startElement(uri, localName, qName, atts);
  95         state = AFTER_START_ELEMENT;
  96         bufLen = 0;
  97     }
  98 
  99     public void endElement(String uri, String localName, String qName) throws SAXException {
 100         processPendingText();
 101         super.endElement(uri, localName, qName);
 102         state = AFTER_END_ELEMENT;
 103     }
 104 
 105     /**
 106      * Forwars the buffered characters if it contains any non-whitespace
 107      * character.
 108      */
 109     private void processPendingText() throws SAXException {
 110         if(state==AFTER_START_ELEMENT) {
 111             for( int i=bufLen-1; i>=0; i-- )
 112                 if( !WhiteSpaceProcessor.isWhiteSpace(buf[i]) ) {
 113                     super.characters(buf, 0, bufLen);
 114                     return;
 115                }
 116         }
 117     }
 118 
 119     public void ignorableWhitespace(char[] ch, int start, int length) throws SAXException {
 120         // ignore completely.
 121     }
 122 }