1 // Protocol Buffers - Google's data interchange format 2 // Copyright 2008 Google Inc. All rights reserved. 3 // https://developers.google.com/protocol-buffers/ 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 /** 34 * Interface that generated extensions implement. 35 * 36 * @author liujisi@google.com (Jisi Liu) 37 */ 38 public abstract class Extension<ContainingType extends MessageLite, Type> { 39 /** Returns the field number of the extension. */ getNumber()40 public abstract int getNumber(); 41 42 /** Returns the type of the field. */ getLiteType()43 public abstract WireFormat.FieldType getLiteType(); 44 45 /** Returns whether it is a repeated field. */ isRepeated()46 public abstract boolean isRepeated(); 47 48 /** Returns the descriptor of the extension. */ getDescriptor()49 public abstract Descriptors.FieldDescriptor getDescriptor(); 50 51 /** Returns the default value of the extension field. */ getDefaultValue()52 public abstract Type getDefaultValue(); 53 54 /** 55 * Returns the default instance of the extension field, if it's a message 56 * extension. 57 */ getMessageDefaultInstance()58 public abstract MessageLite getMessageDefaultInstance(); 59 60 // All the methods below are extension implementation details. 61 62 /** 63 * The API type that the extension is used for. 64 */ 65 protected enum ExtensionType { 66 IMMUTABLE, 67 MUTABLE, 68 PROTO1, 69 } 70 getExtensionType()71 protected ExtensionType getExtensionType() { 72 // TODO(liujisi): make this abstract after we fix proto1. 73 return ExtensionType.IMMUTABLE; 74 } 75 76 /** 77 * Type of a message extension. 78 */ 79 public enum MessageType { 80 PROTO1, 81 PROTO2, 82 } 83 84 /** 85 * If the extension is a message extension (i.e., getLiteType() == MESSAGE), 86 * returns the type of the message, otherwise undefined. 87 */ getMessageType()88 public MessageType getMessageType() { 89 return MessageType.PROTO2; 90 } 91 fromReflectionType(Object value)92 protected abstract Object fromReflectionType(Object value); singularFromReflectionType(Object value)93 protected abstract Object singularFromReflectionType(Object value); toReflectionType(Object value)94 protected abstract Object toReflectionType(Object value); singularToReflectionType(Object value)95 protected abstract Object singularToReflectionType(Object value); 96 } 97