01 /*
02 * Copyright 2008-2015 the original author or authors.
03 *
04 * Licensed under the Apache License, Version 2.0 (the "License");
05 * you may not use this file except in compliance with the License.
06 * You may obtain a copy of the License at
07 *
08 * http://www.apache.org/licenses/LICENSE-2.0
09 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16 package org.codehaus.griffon.runtime.core;
17
18 import griffon.core.Context;
19
20 import javax.annotation.Nonnull;
21 import javax.annotation.Nullable;
22
23 /**
24 * @author Andres Almiray
25 * @since 2.2.0
26 */
27 public abstract class AbstractContext implements Context {
28 protected Context parentContext;
29
30 public AbstractContext(@Nullable Context parentContext) {
31 this.parentContext = parentContext;
32 }
33
34 @Nullable
35 @Override
36 @SuppressWarnings("unchecked")
37 public <T> T get(@Nonnull String key, @Nullable T defaultValue) {
38 T value = (T) get(key);
39 return value != null ? value : defaultValue;
40 }
41
42 @Nullable
43 @Override
44 public Object getAt(@Nonnull String key) {
45 return get(key);
46 }
47
48 @Nullable
49 @Override
50 public <T> T getAt(@Nonnull String key, @Nullable T defaultValue) {
51 return get(key, defaultValue);
52 }
53
54 @Nullable
55 @Override
56 public Object get(@Nonnull String key) {
57 if (containsKey(key)) {
58 return doGet(key);
59 } else if (parentContext != null) {
60 return parentContext.get(key);
61 } else {
62 return null;
63 }
64 }
65
66 @Override
67 public void destroy() {
68 parentContext = null;
69 }
70
71 @Nullable
72 protected abstract Object doGet(@Nonnull String key);
73 }
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