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1   // Copyright 2008 Thiago H. de Paula Figueiredo
2   //
3   // Licensed under the Apache License, Version 2.0 (the "License");
4   // you may not use this file except in compliance with the License.
5   // You may obtain a copy of the License at
6   //
7   //     http://www.apache.org/licenses/LICENSE-2.0
8   //
9   // Unless required by applicable law or agreed to in writing, software
10  // distributed under the License is distributed on an "AS IS" BASIS,
11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12  // See the License for the specific language governing permissions and
13  // limitations under the License.
14  
15  package br.com.arsmachina.tapestrycrud.services.impl;
16  
17  import java.io.Serializable;
18  
19  import org.apache.tapestry5.EventContext;
20  import org.apache.tapestry5.PrimaryKeyEncoder;
21  
22  import br.com.arsmachina.tapestrycrud.encoder.ActivationContextEncoder;
23  
24  /**
25   * An {@link ActivationContextEncoder} implementation based in a {@link PrimaryKeyEncoder}.
26   * 
27   * @author Thiago H. de Paula Figueiredo
28   * @param <T> the entity class related to this DAO.
29   * @param <K> the type of the field that represents the entity class' primary key.
30   */
31  class PrimaryKeyEncoderActivationContextEncoder<T, K extends Serializable> implements
32  		ActivationContextEncoder<T> {
33  
34  	final private Class<K> primaryKeyType;
35  
36  	final private PrimaryKeyEncoder<K, T> primaryKeyEncoder;
37  
38  	/**
39  	 * @param primaryKeyType
40  	 */
41  	@SuppressWarnings("unchecked")
42  	public PrimaryKeyEncoderActivationContextEncoder(PrimaryKeyEncoder<K, T> primaryKeyEncoder,
43  			Class<K> primaryKeyType) {
44  
45  		if (primaryKeyType == null) {
46  			throw new IllegalArgumentException("Parameter primaryKeyType cannot be null");
47  		}
48  
49  		if (primaryKeyEncoder == null) {
50  			throw new IllegalArgumentException("Parameter primaryKeyEncoder cannot be null");
51  		}
52  
53  		this.primaryKeyEncoder = primaryKeyEncoder;
54  		this.primaryKeyType = primaryKeyType;
55  
56  	}
57  
58  	/**
59  	 * @see br.com.arsmachina.tapestrycrud.encoder.ActivationContextEncoder#toActivationContext(java.lang.Object)
60  	 */
61  	public Object toActivationContext(T object) {
62  		return primaryKeyEncoder.toKey(object);
63  	}
64  
65  	/**
66  	 * @see br.com.arsmachina.tapestrycrud.encoder.ActivationContextEncoder#toObject(org.apache.tapestry5.EventContext)
67  	 */
68  	public T toObject(EventContext value) {
69  		return primaryKeyEncoder.toValue(value.get(primaryKeyType, 0));
70  	}
71  
72  }