Thu, 31 Aug 2017 15:18:52 +0800
merge
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 1997, 2011, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. Oracle designates this |
aoqi@0 | 8 | * particular file as subject to the "Classpath" exception as provided |
aoqi@0 | 9 | * by Oracle in the LICENSE file that accompanied this code. |
aoqi@0 | 10 | * |
aoqi@0 | 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 14 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 15 | * accompanied this code). |
aoqi@0 | 16 | * |
aoqi@0 | 17 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 20 | * |
aoqi@0 | 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 22 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 23 | * questions. |
aoqi@0 | 24 | */ |
aoqi@0 | 25 | |
aoqi@0 | 26 | package com.sun.xml.internal.bind.api; |
aoqi@0 | 27 | |
aoqi@0 | 28 | import javax.xml.bind.JAXBContext; |
aoqi@0 | 29 | import javax.xml.bind.Unmarshaller; |
aoqi@0 | 30 | import javax.xml.bind.ValidationEventHandler; |
aoqi@0 | 31 | import javax.xml.bind.annotation.XmlAnyElement; |
aoqi@0 | 32 | |
aoqi@0 | 33 | import com.sun.istack.internal.NotNull; |
aoqi@0 | 34 | import com.sun.istack.internal.Nullable; |
aoqi@0 | 35 | |
aoqi@0 | 36 | /** |
aoqi@0 | 37 | * Dynamically locates classes to represent elements discovered during the unmarshalling. |
aoqi@0 | 38 | * |
aoqi@0 | 39 | * <p> |
aoqi@0 | 40 | * <b>THIS INTERFACE IS SUBJECT TO CHANGE WITHOUT NOTICE.</b> |
aoqi@0 | 41 | * |
aoqi@0 | 42 | * <h2>Background</h2> |
aoqi@0 | 43 | * <p> |
aoqi@0 | 44 | * {@link JAXBContext#newInstance(Class...)} requires that application informs JAXB |
aoqi@0 | 45 | * about all the classes that it may see in the instance document. While this allows |
aoqi@0 | 46 | * JAXB to take time to optimize the unmarshalling, it is sometimes inconvenient |
aoqi@0 | 47 | * for applications. |
aoqi@0 | 48 | * |
aoqi@0 | 49 | * <p> |
aoqi@0 | 50 | * This is where {@link ClassResolver} comes to resucue. |
aoqi@0 | 51 | * |
aoqi@0 | 52 | * <p> |
aoqi@0 | 53 | * A {@link ClassResolver} instance can be specified on {@link Unmarshaller} via |
aoqi@0 | 54 | * {@link Unmarshaller#setProperty(String, Object)} as follows: |
aoqi@0 | 55 | * |
aoqi@0 | 56 | * <pre> |
aoqi@0 | 57 | * unmarshaller.setProperty( ClassResolver.class.getName(), new MyClassResolverImpl() ); |
aoqi@0 | 58 | * </pre> |
aoqi@0 | 59 | * |
aoqi@0 | 60 | * <p> |
aoqi@0 | 61 | * When an {@link Unmarshaller} encounters (i) an unknown root element or (ii) unknown |
aoqi@0 | 62 | * elements where unmarshaller is trying to unmarshal into {@link XmlAnyElement} with |
aoqi@0 | 63 | * <tt>lax=true</tt>, unmarshaller calls {@link #resolveElementName(String, String)} |
aoqi@0 | 64 | * method to see if the application may be able to supply a class that corresponds |
aoqi@0 | 65 | * to that class. |
aoqi@0 | 66 | * |
aoqi@0 | 67 | * <p> |
aoqi@0 | 68 | * When a {@link Class} is returned, a new {@link JAXBContext} is created with |
aoqi@0 | 69 | * all the classes known to it so far, plus a new class returned. This operation |
aoqi@0 | 70 | * may fail (for example because of some conflicting annotations.) This failure |
aoqi@0 | 71 | * is handled just like {@link Exception}s thrown from |
aoqi@0 | 72 | * {@link ClassResolver#resolveElementName(String, String)}. |
aoqi@0 | 73 | * |
aoqi@0 | 74 | * @author Kohsuke Kawaguchi |
aoqi@0 | 75 | * @since 2.1 |
aoqi@0 | 76 | */ |
aoqi@0 | 77 | public abstract class ClassResolver { |
aoqi@0 | 78 | /** |
aoqi@0 | 79 | * JAXB calls this method when it sees an unknown element. |
aoqi@0 | 80 | * |
aoqi@0 | 81 | * <p> |
aoqi@0 | 82 | * See the class javadoc for details. |
aoqi@0 | 83 | * |
aoqi@0 | 84 | * @param nsUri |
aoqi@0 | 85 | * Namespace URI of the unknown element. Can be empty but never null. |
aoqi@0 | 86 | * @param localName |
aoqi@0 | 87 | * Local name of the unknown element. Never be empty nor null. |
aoqi@0 | 88 | * |
aoqi@0 | 89 | * @return |
aoqi@0 | 90 | * If a non-null class is returned, it will be used to unmarshal this element. |
aoqi@0 | 91 | * If null is returned, the resolution is assumed to be failed, and |
aoqi@0 | 92 | * the unmarshaller will behave as if there was no {@link ClassResolver} |
aoqi@0 | 93 | * to begin with (that is, to report it to {@link ValidationEventHandler}, |
aoqi@0 | 94 | * then move on.) |
aoqi@0 | 95 | * |
aoqi@0 | 96 | * @throws Exception |
aoqi@0 | 97 | * Throwing any {@link RuntimeException} causes the unmarshaller to stop |
aoqi@0 | 98 | * immediately. The exception will be propagated up the call stack. |
aoqi@0 | 99 | * Throwing any other checked {@link Exception} results in the error |
aoqi@0 | 100 | * reproted to {@link ValidationEventHandler} (just like any other error |
aoqi@0 | 101 | * during the unmarshalling.) |
aoqi@0 | 102 | */ |
aoqi@0 | 103 | public abstract @Nullable Class<?> resolveElementName(@NotNull String nsUri, @NotNull String localName) throws Exception; |
aoqi@0 | 104 | } |