1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // http://code.google.com/p/protobuf/ 4 // 5 // Redistribution and use in source and binary forms, with or without 6 // modification, are permitted provided that the following conditions are 7 // met: 8 // 9 // * Redistributions of source code must retain the above copyright 10 // notice, this list of conditions and the following disclaimer. 11 // * Redistributions in binary form must reproduce the above 12 // copyright notice, this list of conditions and the following disclaimer 13 // in the documentation and/or other materials provided with the 14 // distribution. 15 // * Neither the name of Google Inc. nor the names of its 16 // contributors may be used to endorse or promote products derived from 17 // this software without specific prior written permission. 18 // 19 // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31 package com.google.protobuf; 32 33 import java.util.List; 34 35 /** 36 * An interface extending {@code List<String>} that also provides access to the 37 * items of the list as UTF8-encoded ByteString objects. This is used by the 38 * protocol buffer implementation to support lazily converting bytes parsed 39 * over the wire to String objects until needed and also increases the 40 * efficiency of serialization if the String was never requested as the 41 * ByteString is already cached. 42 * <p> 43 * This only adds additional methods that are required for the use in the 44 * protocol buffer code in order to be able successfully round trip byte arrays 45 * through parsing and serialization without conversion to strings. It's not 46 * attempting to support the functionality of say {@code List<ByteString>}, hence 47 * why only these two very specific methods are added. 48 * 49 * @author jonp@google.com (Jon Perlow) 50 */ 51 public interface LazyStringList extends List<String> { 52 53 /** 54 * Returns the element at the specified position in this list as a ByteString. 55 * 56 * @param index index of the element to return 57 * @return the element at the specified position in this list 58 * @throws IndexOutOfBoundsException if the index is out of range 59 * ({@code index < 0 || index >= size()}) 60 */ getByteString(int index)61 ByteString getByteString(int index); 62 63 /** 64 * Appends the specified element to the end of this list (optional 65 * operation). 66 * 67 * @param element element to be appended to this list 68 * @throws UnsupportedOperationException if the <tt>add</tt> operation 69 * is not supported by this list 70 */ add(ByteString element)71 void add(ByteString element); 72 73 /** 74 * Returns an unmodifiable List of the underlying elements, each of 75 * which is either a {@code String} or its equivalent UTF-8 encoded 76 * {@code ByteString}. It is an error for the caller to modify the returned 77 * List, and attempting to do so will result in an 78 * {@link UnsupportedOperationException}. 79 */ getUnderlyingElements()80 List<?> getUnderlyingElements(); 81 } 82