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Java > Open Source Codes > org > apache > cayenne > util > ListResponse


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19
20 package org.apache.cayenne.util;
21
22 import java.io.Serializable JavaDoc;
23 import java.util.ArrayList JavaDoc;
24 import java.util.Collections JavaDoc;
25 import java.util.List JavaDoc;
26
27 import org.apache.cayenne.QueryResponse;
28
29 /**
30  * A QueryResponse optimized to hold a single object or data row list.
31  *
32  * @since 1.2
33  * @author Andrus Adamchik
34  */
35 public class ListResponse implements QueryResponse, Serializable JavaDoc {
36
37     protected List JavaDoc objectList;
38
39     protected transient int currentIndex;
40
41     /**
42      * Creates an empty response.
43      */
44     public ListResponse() {
45         this.objectList = new ArrayList JavaDoc(1);
46     }
47
48     public ListResponse(Object JavaDoc object) {
49         this.objectList = Collections.singletonList(object);
50     }
51
52     public ListResponse(List JavaDoc objectList) {
53         this.objectList = objectList;
54     }
55
56     public int size() {
57         return 1;
58     }
59
60     public boolean isList() {
61         if (currentIndex != 1) {
62             throw new IndexOutOfBoundsException JavaDoc("Past iteration end: " + currentIndex);
63         }
64
65         return true;
66     }
67
68     public List JavaDoc currentList() {
69         if (currentIndex != 1) {
70             throw new IndexOutOfBoundsException JavaDoc("Past iteration end: " + currentIndex);
71         }
72
73         return objectList;
74     }
75
76     public int[] currentUpdateCount() {
77         throw new IllegalStateException JavaDoc("Current object is not an update count");
78     }
79
80     public boolean next() {
81         return ++currentIndex <= 1;
82     }
83
84     public void reset() {
85         // use a zero-based index, not -1, as this will simplify serialization handling
86 currentIndex = 0;
87     }
88
89     public List JavaDoc firstList() {
90         return objectList;
91     }
92
93     public int[] firstUpdateCount() {
94         return new int[0];
95     }
96 }
97
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