001/** 002 * 003 * Copyright © 2014-2018 Florian Schmaus 004 * 005 * Licensed under the Apache License, Version 2.0 (the "License"); 006 * you may not use this file except in compliance with the License. 007 * You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 018package org.jivesoftware.smack.provider; 019 020import org.jivesoftware.smack.packet.Element; 021import org.jivesoftware.smack.util.ParserUtils; 022 023import org.xmlpull.v1.XmlPullParser; 024 025/** 026 * Smack provider are the parsers used to deserialize raw XMPP into the according Java {@link Element}s. 027 * <p> 028 * At any time when {@link #parse(XmlPullParser, int)} is invoked any type of exception can be thrown. If the parsed 029 * element does not follow the specification, for example by putting a string where only integers are allowed, then a 030 * {@link org.jivesoftware.smack.SmackException} should be thrown. 031 * </p> 032 * 033 * @author Florian Schmaus 034 * @param <E> the type of the resulting element. 035 */ 036public abstract class Provider<E extends Element> { 037 038 public final E parse(XmlPullParser parser) throws Exception { 039 // XPP3 calling convention assert: Parser should be at start tag 040 ParserUtils.assertAtStartTag(parser); 041 042 final int initialDepth = parser.getDepth(); 043 E e = parse(parser, initialDepth); 044 045 // XPP3 calling convention assert: Parser should be at end tag of the consumed/parsed element 046 ParserUtils.forwardToEndTagOfDepth(parser, initialDepth); 047 return e; 048 } 049 050 public abstract E parse(XmlPullParser parser, int initialDepth) throws Exception; 051}