1 /* 2 * Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. Oracle designates this 8 * particular file as subject to the "Classpath" exception as provided 9 * by Oracle in the LICENSE file that accompanied this code. 10 * 11 * This code is distributed in the hope that it will be useful, but WITHOUT 12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 14 * version 2 for more details (a copy is included in the LICENSE file that 15 * accompanied this code). 16 * 17 * You should have received a copy of the GNU General Public License version 18 * 2 along with this work; if not, write to the Free Software Foundation, 19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 20 * 21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 22 * or visit www.oracle.com if you need additional information or have any 23 * questions. 24 */ 25 26 package com.sun.xml.internal.bind; 27 28 import javax.xml.bind.Marshaller; 29 30 /** 31 * Optional interface that can be implemented by JAXB-bound objects 32 * to handle cycles in the object graph. 33 * 34 * <p> 35 * As discussed in <a href="https://javaee.github.io/jaxb-v2/doc/user-guide/ch03.html#annotating-your-classes-mapping-cyclic-references-to-xml"> 36 * the users' guide</a>, normally a cycle in the object graph causes the marshaller to report an error, 37 * and when an error is found, the JAXB RI recovers by cutting the cycle arbitrarily. 38 * This is not always a desired behavior. 39 * 40 * <p> 41 * Implementing this interface allows user application to change this behavior. 42 * 43 * @since JAXB 2.1 EA2 44 * @author Kohsuke Kawaguchi 45 */ 46 public interface CycleRecoverable { 47 /** 48 * Called when a cycle is detected by the JAXB RI marshaller 49 * to nominate a new object to be marshalled instead. 50 * 51 * @param context 52 * This object is provided by the JAXB RI to inform 53 * the object about the marshalling process that's going on. 54 * 55 * 56 * @return 57 * the object to be marshalled instead of {@code this} object. 58 * Or return null to indicate that the JAXB RI should behave 59 * just like when your object does not implement {@link CycleRecoverable} 60 * (IOW, cut the cycle arbitrarily and try to go on.) 61 */ 62 Object onCycleDetected(Context context); 63 64 /** 65 * This interface is implemented by the JAXB RI to provide 66 * information about the on-going marshalling process. 67 * 68 * <p> 69 * We may add more methods in the future, so please do not 70 * implement this interface in your application. 71 */ 72 public interface Context { 73 /** 74 * Returns the marshaller object that's doing the marshalling. 75 * 76 * @return 77 * always non-null. 78 */ 79 Marshaller getMarshaller(); 80 } 81 }