|
1
|
/**
|
|
2
|
* Copyright (C) 2009 EDIT
|
|
3
|
* European Distributed Institute of Taxonomy
|
|
4
|
* http://www.e-taxonomy.eu
|
|
5
|
*
|
|
6
|
* The contents of this file are subject to the Mozilla Public License Version 1.1
|
|
7
|
* See LICENSE.TXT at the top of this package for the full license terms.
|
|
8
|
*/
|
|
9
|
|
|
10
|
package eu.etaxonomy.cdm.api.service.pager;
|
|
11
|
|
|
12
|
import java.util.List;
|
|
13
|
|
|
14
|
/**
|
|
15
|
* Abstract class that represents a single page in a set of objects
|
|
16
|
* returned from a query (possibly a subset of the total number of matching objects
|
|
17
|
* available).
|
|
18
|
*
|
|
19
|
* NOTE: Indices for objects and pages are 0-based.
|
|
20
|
* @author ben
|
|
21
|
*/
|
|
22
|
public interface Pager<T> {
|
|
23
|
/**
|
|
24
|
* The total number of pages available for this query, or 0 if there are
|
|
25
|
* no matching objects
|
|
26
|
*
|
|
27
|
* @return The number of pages available
|
|
28
|
*/
|
|
29
|
public Integer getPagesAvailable();
|
|
30
|
|
|
31
|
/**
|
|
32
|
* The index of the next page in this result set, or null if this is the
|
|
33
|
* last page in the result set.
|
|
34
|
* @return The index of the next page
|
|
35
|
*/
|
|
36
|
public Integer getNextIndex();
|
|
37
|
|
|
38
|
/**
|
|
39
|
* The index of the previous page in this result set, or null if this is the
|
|
40
|
* first page in the result set.
|
|
41
|
* @return The index of the previous page
|
|
42
|
*/
|
|
43
|
public Integer getPrevIndex();
|
|
44
|
|
|
45
|
/**
|
|
46
|
* The index of this page.
|
|
47
|
*
|
|
48
|
* NOTE: Indices for objects and pages are 0-based.
|
|
49
|
* @return The index of this page
|
|
50
|
*/
|
|
51
|
public Integer getCurrentIndex();
|
|
52
|
|
|
53
|
/**
|
|
54
|
* Get a string label for a given page
|
|
55
|
* (NOTE: Labels may not be calculated for each page in the result set,
|
|
56
|
* especially if the result set is large or the operation for calculating the
|
|
57
|
* label is expensive. The indices of the pages for which labels are available
|
|
58
|
* are given by {@link #getIndices()}.
|
|
59
|
*
|
|
60
|
* @param index
|
|
61
|
* @return A label for the page indicated or null if this pager has not calculated a label for that page
|
|
62
|
*/
|
|
63
|
public String getPageNumber(int index);
|
|
64
|
|
|
65
|
/**
|
|
66
|
* Gets the size of pages in this result set. Can be null if all matching
|
|
67
|
* objects should be returned.
|
|
68
|
* @return The page size
|
|
69
|
*/
|
|
70
|
public Integer getPageSize();
|
|
71
|
|
|
72
|
/**
|
|
73
|
* Get a list of page indices for which labels are available.
|
|
74
|
* @return A list of indices
|
|
75
|
*/
|
|
76
|
public List<Integer> getIndices();
|
|
77
|
|
|
78
|
/**
|
|
79
|
* Get the total number of objects in this result set (not in this page).
|
|
80
|
* If count > {@link #getPageSize()} then {@link #getPagesAvailable()} > 1
|
|
81
|
* @return the total number of objects available.
|
|
82
|
*/
|
|
83
|
public Long getCount();
|
|
84
|
|
|
85
|
/**
|
|
86
|
* Returns the index of the first record in this result set
|
|
87
|
* @return
|
|
88
|
*/
|
|
89
|
public Integer getFirstRecord();
|
|
90
|
|
|
91
|
/**
|
|
92
|
* Returns the index of the last record in this result set
|
|
93
|
* @return
|
|
94
|
*/
|
|
95
|
public Integer getLastRecord();
|
|
96
|
|
|
97
|
/**
|
|
98
|
* Returns the records in this page.
|
|
99
|
* @return
|
|
100
|
*/
|
|
101
|
public List<T> getRecords();
|
|
102
|
|
|
103
|
/**
|
|
104
|
* Returns a suggested query string (only applicable for free-text / lucene queries).
|
|
105
|
*
|
|
106
|
* Usually only calculated if there were no matching results for the original query.
|
|
107
|
* @return
|
|
108
|
*/
|
|
109
|
public String getSuggestion();
|
|
110
|
|
|
111
|
}
|