1 /* 2 * $HeadURL: http://svn.apache.org/repos/asf/httpcomponents/httpcore/trunk/module-main/src/main/java/org/apache/http/message/BasicListHeaderIterator.java $ 3 * $Revision: 584542 $ 4 * $Date: 2007-10-14 06:29:34 -0700 (Sun, 14 Oct 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 35 import java.util.List; 36 import java.util.NoSuchElementException; 37 38 import org.apache.http.Header; 39 import org.apache.http.HeaderIterator; 40 41 42 /** 43 * Implementation of a {@link HeaderIterator} based on a {@link List}. 44 * For use by {@link HeaderGroup}. 45 * 46 * @version $Revision: 584542 $ 47 * 48 * @deprecated Please use {@link java.net.URL#openConnection} instead. 49 * Please visit <a href="http://android-developers.blogspot.com/2011/09/androids-http-clients.html">this webpage</a> 50 * for further details. 51 */ 52 @Deprecated 53 public class BasicListHeaderIterator implements HeaderIterator { 54 55 /** 56 * A list of headers to iterate over. 57 * Not all elements of this array are necessarily part of the iteration. 58 */ 59 protected final List allHeaders; 60 61 62 /** 63 * The position of the next header in {@link #allHeaders allHeaders}. 64 * Negative if the iteration is over. 65 */ 66 protected int currentIndex; 67 68 69 /** 70 * The position of the last returned header. 71 * Negative if none has been returned so far. 72 */ 73 protected int lastIndex; 74 75 76 /** 77 * The header name to filter by. 78 * <code>null</code> to iterate over all headers in the array. 79 */ 80 protected String headerName; 81 82 83 84 /** 85 * Creates a new header iterator. 86 * 87 * @param headers a list of headers over which to iterate 88 * @param name the name of the headers over which to iterate, or 89 * <code>null</code> for any 90 */ 91 public BasicListHeaderIterator(List headers, String name) { 92 if (headers == null) { 93 throw new IllegalArgumentException 94 ("Header list must not be null."); 95 } 96 97 this.allHeaders = headers; 98 this.headerName = name; 99 this.currentIndex = findNext(-1); 100 this.lastIndex = -1; 101 } 102 103 104 /** 105 * Determines the index of the next header. 106 * 107 * @param from one less than the index to consider first, 108 * -1 to search for the first header 109 * 110 * @return the index of the next header that matches the filter name, 111 * or negative if there are no more headers 112 */ 113 protected int findNext(int from) { 114 if (from < -1) 115 return -1; 116 117 final int to = this.allHeaders.size()-1; 118 boolean found = false; 119 while (!found && (from < to)) { 120 from++; 121 found = filterHeader(from); 122 } 123 return found ? from : -1; 124 } 125 126 127 /** 128 * Checks whether a header is part of the iteration. 129 * 130 * @param index the index of the header to check 131 * 132 * @return <code>true</code> if the header should be part of the 133 * iteration, <code>false</code> to skip 134 */ 135 protected boolean filterHeader(int index) { 136 if (this.headerName == null) 137 return true; 138 139 // non-header elements, including null, will trigger exceptions 140 final String name = ((Header)this.allHeaders.get(index)).getName(); 141 142 return this.headerName.equalsIgnoreCase(name); 143 } 144 145 146 // non-javadoc, see interface HeaderIterator 147 public boolean hasNext() { 148 return (this.currentIndex >= 0); 149 } 150 151 152 /** 153 * Obtains the next header from this iteration. 154 * 155 * @return the next header in this iteration 156 * 157 * @throws NoSuchElementException if there are no more headers 158 */ 159 public Header nextHeader() 160 throws NoSuchElementException { 161 162 final int current = this.currentIndex; 163 if (current < 0) { 164 throw new NoSuchElementException("Iteration already finished."); 165 } 166 167 this.lastIndex = current; 168 this.currentIndex = findNext(current); 169 170 return (Header) this.allHeaders.get(current); 171 } 172 173 174 /** 175 * Returns the next header. 176 * Same as {@link #nextHeader nextHeader}, but not type-safe. 177 * 178 * @return the next header in this iteration 179 * 180 * @throws NoSuchElementException if there are no more headers 181 */ 182 public final Object next() 183 throws NoSuchElementException { 184 return nextHeader(); 185 } 186 187 188 /** 189 * Removes the header that was returned last. 190 */ 191 public void remove() 192 throws UnsupportedOperationException { 193 194 if (this.lastIndex < 0) { 195 throw new IllegalStateException("No header to remove."); 196 } 197 this.allHeaders.remove(this.lastIndex); 198 this.lastIndex = -1; 199 this.currentIndex--; // adjust for the removed element 200 } 201 } 202
