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 public class BasicHeaderElementIterator implements HeaderElementIterator { 52 53 private final HeaderIterator headerIt; 54 private final HeaderValueParser parser; 55 56 private HeaderElement currentElement = null; 57 private CharArrayBuffer buffer = null; 58 private ParserCursor cursor = null; 59 60 /** 61 * Creates a new instance of BasicHeaderElementIterator 62 */ BasicHeaderElementIterator( final HeaderIterator headerIterator, final HeaderValueParser parser)63 public BasicHeaderElementIterator( 64 final HeaderIterator headerIterator, 65 final HeaderValueParser parser) { 66 if (headerIterator == null) { 67 throw new IllegalArgumentException("Header iterator may not be null"); 68 } 69 if (parser == null) { 70 throw new IllegalArgumentException("Parser may not be null"); 71 } 72 this.headerIt = headerIterator; 73 this.parser = parser; 74 } 75 76 BasicHeaderElementIterator(final HeaderIterator headerIterator)77 public BasicHeaderElementIterator(final HeaderIterator headerIterator) { 78 this(headerIterator, BasicHeaderValueParser.DEFAULT); 79 } 80 81 bufferHeaderValue()82 private void bufferHeaderValue() { 83 this.cursor = null; 84 this.buffer = null; 85 while (this.headerIt.hasNext()) { 86 Header h = this.headerIt.nextHeader(); 87 if (h instanceof FormattedHeader) { 88 this.buffer = ((FormattedHeader) h).getBuffer(); 89 this.cursor = new ParserCursor(0, this.buffer.length()); 90 this.cursor.updatePos(((FormattedHeader) h).getValuePos()); 91 break; 92 } else { 93 String value = h.getValue(); 94 if (value != null) { 95 this.buffer = new CharArrayBuffer(value.length()); 96 this.buffer.append(value); 97 this.cursor = new ParserCursor(0, this.buffer.length()); 98 break; 99 } 100 } 101 } 102 } 103 parseNextElement()104 private void parseNextElement() { 105 // loop while there are headers left to parse 106 while (this.headerIt.hasNext() || this.cursor != null) { 107 if (this.cursor == null || this.cursor.atEnd()) { 108 // get next header value 109 bufferHeaderValue(); 110 } 111 // Anything buffered? 112 if (this.cursor != null) { 113 // loop while there is data in the buffer 114 while (!this.cursor.atEnd()) { 115 HeaderElement e = this.parser.parseHeaderElement(this.buffer, this.cursor); 116 if (!(e.getName().length() == 0 && e.getValue() == null)) { 117 // Found something 118 this.currentElement = e; 119 return; 120 } 121 } 122 // if at the end of the buffer 123 if (this.cursor.atEnd()) { 124 // discard it 125 this.cursor = null; 126 this.buffer = null; 127 } 128 } 129 } 130 } 131 hasNext()132 public boolean hasNext() { 133 if (this.currentElement == null) { 134 parseNextElement(); 135 } 136 return this.currentElement != null; 137 } 138 nextElement()139 public HeaderElement nextElement() throws NoSuchElementException { 140 if (this.currentElement == null) { 141 parseNextElement(); 142 } 143 144 if (this.currentElement == null) { 145 throw new NoSuchElementException("No more header elements available"); 146 } 147 148 HeaderElement element = this.currentElement; 149 this.currentElement = null; 150 return element; 151 } 152 next()153 public final Object next() throws NoSuchElementException { 154 return nextElement(); 155 } 156 remove()157 public void remove() throws UnsupportedOperationException { 158 throw new UnsupportedOperationException("Remove not supported"); 159 } 160 161 }