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1   /**
2    * Copyright (c) 2008-2012, http://www.snakeyaml.org
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    *     http://www.apache.org/licenses/LICENSE-2.0
9    *
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 examples;
17  
18  import java.util.List;
19  import java.util.Map;
20  
21  import junit.framework.TestCase;
22  
23  import org.yaml.snakeyaml.Yaml;
24  import org.yaml.snakeyaml.constructor.Constructor;
25  import org.yaml.snakeyaml.nodes.MappingNode;
26  import org.yaml.snakeyaml.nodes.NodeId;
27  
28  /**
29   * Example for http://code.google.com/p/snakeyaml/wiki/howto
30   */
31  public class SelectiveConstructorTest extends TestCase {
32      class SelectiveConstructor extends Constructor {
33          public SelectiveConstructor() {
34              // define a custom way to create a mapping node
35              yamlClassConstructors.put(NodeId.mapping, new MyPersistentObjectConstruct());
36          }
37  
38          class MyPersistentObjectConstruct extends Constructor.ConstructMapping {
39              @Override
40              protected Object constructJavaBean2ndStep(MappingNode node, Object object) {
41                  Class<?> type = node.getType();
42                  if (type.equals(MyPersistentObject.class)) {
43                      // create a map
44                      Map<Object, Object> map = constructMapping(node);
45                      String id = (String) map.get("id");
46                      return new MyPersistentObject(id, 17);
47                  } else {
48                      // create JavaBean
49                      return super.constructJavaBean2ndStep(node, object);
50                  }
51              }
52          }
53      }
54  
55      public void testConstructor() {
56          Yaml yaml = new Yaml(new SelectiveConstructor());
57          List<?> data = (List<?>) yaml
58                  .load("- 1\n- 2\n- !!examples.MyPersistentObject {amount: 222, id: persistent}");
59          // System.out.println(data);
60          assertEquals(3, data.size());
61          MyPersistentObject myObject = (MyPersistentObject) data.get(2);
62          assertEquals(17, myObject.getAmount());
63          assertEquals("persistent", myObject.getId());
64      }
65  }
66  
67  class MyPersistentObject {
68      private String id;
69      private int amount;
70  
71      public MyPersistentObject() {
72          this.id = "noid";
73          this.amount = 222;
74      }
75  
76      public MyPersistentObject(String id, int amount) {
77          this.id = id;
78          this.amount = amount;
79      }
80  
81      public String getId() {
82          return id;
83      }
84  
85      public void setId(String id) {
86          this.id = id;
87      }
88  
89      public int getAmount() {
90          return amount;
91      }
92  
93      public void setAmount(int amount) {
94          this.amount = amount;
95      }
96  
97      @Override
98      public String toString() {
99          return "MyPersistentObject [id=" + id + ", amount=" + amount + "]";
100     }
101 }