1/*
2 * Copyright (c) 1997, 2012, 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
26package com.sun.xml.internal.bind.v2.runtime.reflect;
27
28import com.sun.xml.internal.bind.api.AccessorException;
29
30/**
31 * {@link Accessor} wrapper that replaces a null with an empty collection.
32 *
33 * <p>
34 * This is so that JAX-WS property accessor will work like an ordinary getter.
35 *
36 *
37 * @author Kohsuke Kawaguchi
38 */
39public class NullSafeAccessor<B,V,P> extends Accessor<B,V> {
40    private final Accessor<B,V> core;
41    private final Lister<B,V,?,P> lister;
42
43    public NullSafeAccessor(Accessor<B,V> core, Lister<B,V,?,P> lister) {
44        super(core.getValueType());
45        this.core = core;
46        this.lister = lister;
47    }
48
49    public V get(B bean) throws AccessorException {
50        V v = core.get(bean);
51        if(v==null) {
52            // creates a new object
53            P pack = lister.startPacking(bean,core);
54            lister.endPacking(pack,bean,core);
55            v = core.get(bean);
56        }
57        return v;
58    }
59
60    public void set(B bean, V value) throws AccessorException {
61        core.set(bean,value);
62    }
63}
64