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      1 /*
      2  * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/message/BasicHeaderElementIterator.java $
      3  * $Revision: 592088 $
      4  * $Date: 2007-11-05 09:03:39 -0800 (Mon, 05 Nov 2007) $
      5  *
      6  * ====================================================================
      7  * Licensed to the Apache Software Foundation (ASF) under one
      8  * or more contributor license agreements.  See the NOTICE file
      9  * distributed with this work for additional information
     10  * regarding copyright ownership.  The ASF licenses this file
     11  * to you under the Apache License, Version 2.0 (the
     12  * "License"); you may not use this file except in compliance
     13  * with the License.  You may obtain a copy of the License at
     14  *
     15  *   http://www.apache.org/licenses/LICENSE-2.0
     16  *
     17  * Unless required by applicable law or agreed to in writing,
     18  * software distributed under the License is distributed on an
     19  * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
     20  * KIND, either express or implied.  See the License for the
     21  * specific language governing permissions and limitations
     22  * under the License.
     23  * ====================================================================
     24  *
     25  * This software consists of voluntary contributions made by many
     26  * individuals on behalf of the Apache Software Foundation.  For more
     27  * information on the Apache Software Foundation, please see
     28  * <http://www.apache.org/>.
     29  *
     30  */
     31 
     32 package org.apache.http.message;
     33 
     34 import java.util.NoSuchElementException;
     35 
     36 import org.apache.http.FormattedHeader;
     37 import org.apache.http.Header;
     38 import org.apache.http.HeaderElement;
     39 import org.apache.http.HeaderElementIterator;
     40 import org.apache.http.HeaderIterator;
     41 import org.apache.http.util.CharArrayBuffer;
     42 
     43 /**
     44  * Basic implementation of a {@link HeaderElementIterator}.
     45  *
     46  * @version $Revision: 592088 $
     47  *
     48  * @author Andrea Selva <selva.andre at gmail.com>
     49  * @author Oleg Kalnichevski <oleg at ural.ru>
     50  *
     51  * @deprecated Please use {@link java.net.URL#openConnection} instead.
     52  *     Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a>
     53  *     for further details.
     54  */
     55 @Deprecated
     56 public class BasicHeaderElementIterator implements HeaderElementIterator {
     57 
     58     private final HeaderIterator headerIt;
     59     private final HeaderValueParser parser;
     60 
     61     private HeaderElement currentElement = null;
     62     private CharArrayBuffer buffer = null;
     63     private ParserCursor cursor = null;
     64 
     65     /**
     66      * Creates a new instance of BasicHeaderElementIterator
     67      */
     68     public BasicHeaderElementIterator(
     69             final HeaderIterator headerIterator,
     70             final HeaderValueParser parser) {
     71         if (headerIterator == null) {
     72             throw new IllegalArgumentException("Header iterator may not be null");
     73         }
     74         if (parser == null) {
     75             throw new IllegalArgumentException("Parser may not be null");
     76         }
     77         this.headerIt = headerIterator;
     78         this.parser = parser;
     79     }
     80 
     81 
     82     public BasicHeaderElementIterator(final HeaderIterator headerIterator) {
     83         this(headerIterator, BasicHeaderValueParser.DEFAULT);
     84     }
     85 
     86 
     87     private void bufferHeaderValue() {
     88         this.cursor = null;
     89         this.buffer = null;
     90         while (this.headerIt.hasNext()) {
     91             Header h = this.headerIt.nextHeader();
     92             if (h instanceof FormattedHeader) {
     93                 this.buffer = ((FormattedHeader) h).getBuffer();
     94                 this.cursor = new ParserCursor(0, this.buffer.length());
     95                 this.cursor.updatePos(((FormattedHeader) h).getValuePos());
     96                 break;
     97             } else {
     98                 String value = h.getValue();
     99                 if (value != null) {
    100                     this.buffer = new CharArrayBuffer(value.length());
    101                     this.buffer.append(value);
    102                     this.cursor = new ParserCursor(0, this.buffer.length());
    103                     break;
    104                 }
    105             }
    106         }
    107     }
    108 
    109     private void parseNextElement() {
    110         // loop while there are headers left to parse
    111         while (this.headerIt.hasNext() || this.cursor != null) {
    112             if (this.cursor == null || this.cursor.atEnd()) {
    113                 // get next header value
    114                 bufferHeaderValue();
    115             }
    116             // Anything buffered?
    117             if (this.cursor != null) {
    118                 // loop while there is data in the buffer
    119                 while (!this.cursor.atEnd()) {
    120                     HeaderElement e = this.parser.parseHeaderElement(this.buffer, this.cursor);
    121                     if (!(e.getName().length() == 0 && e.getValue() == null)) {
    122                         // Found something
    123                         this.currentElement = e;
    124                         return;
    125                     }
    126                 }
    127                 // if at the end of the buffer
    128                 if (this.cursor.atEnd()) {
    129                     // discard it
    130                     this.cursor = null;
    131                     this.buffer = null;
    132                 }
    133             }
    134         }
    135     }
    136 
    137     public boolean hasNext() {
    138         if (this.currentElement == null) {
    139             parseNextElement();
    140         }
    141         return this.currentElement != null;
    142     }
    143 
    144     public HeaderElement nextElement() throws NoSuchElementException {
    145         if (this.currentElement == null) {
    146             parseNextElement();
    147         }
    148 
    149         if (this.currentElement == null) {
    150             throw new NoSuchElementException("No more header elements available");
    151         }
    152 
    153         HeaderElement element = this.currentElement;
    154         this.currentElement = null;
    155         return element;
    156     }
    157 
    158     public final Object next() throws NoSuchElementException {
    159         return nextElement();
    160     }
    161 
    162     public void remove() throws UnsupportedOperationException {
    163         throw new UnsupportedOperationException("Remove not supported");
    164     }
    165 
    166 }