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1
5 package org.exoplatform.commons.utils;
6
7 import java.util.* ;
8 import org.exoplatform.commons.exception.ExoMessageException;
9
14 abstract public class PageList {
15 final static public PageList EMPTY_LIST = new ObjectPageList(new ArrayList(), 10) ;
16
17 private int pageSize_ ;
18 private int available_ = 0;
19 private int availablePage_ = 1;
20 protected int currentPage_ = -1 ;
21 protected List currentListPage_ ;
22
23 public PageList(int pageSize) {
24 pageSize_ = pageSize ;
25 }
26
27 public int getPageSize() { return pageSize_ ; }
28 public void setPageSize(int pageSize) {
29 pageSize_ = pageSize ;
30 setAvailablePage(available_) ;
31 }
32
33 public int getCurrentPage() { return currentPage_ ; }
34 public int getAvailable() { return available_ ; }
35
36 public int getAvailablePage() { return availablePage_ ; }
37
38 public List currentPage() throws Exception  {
39 if(currentListPage_ == null) {
40 populateCurrentPage(currentPage_) ;
41 }
42 return currentListPage_ ;
43 }
44
45 abstract protected void populateCurrentPage(int page) throws Exception ;
46
47 public List getPage(int page) throws Exception {
48 checkAndSetPage(page) ;
49 populateCurrentPage(page) ;
50 return currentListPage_ ;
51 }
52
53 abstract public List getAll() throws Exception ;
54
55 protected void checkAndSetPage(int page) throws Exception {
56 if(page < 1 || page > availablePage_) {
57 Object [] args = { Integer.toString(page), Integer.toString(availablePage_) } ;
58 throw new ExoMessageException("PageList.page-out-of-range", args) ;
59 }
60 currentPage_ = page ;
61 }
62
63 protected void setAvailablePage(int available) {
64 available_ = available ;
65 if (available == 0) {
66 availablePage_ = 1 ;
67 currentPage_ = 1 ;
68 } else {
69 int pages = available / pageSize_ ;
70 if ( available % pageSize_ > 0) pages++ ;
71 availablePage_ = pages ;
72 currentPage_ = 1 ;
73 }
74 }
75
76 public int getFrom() {
77 return (currentPage_ - 1) * pageSize_ ;
78 }
79
80 public int getTo() {
81 int to = currentPage_ * pageSize_ ;
82 if (to > available_ ) to = available_ ;
83 return to ;
84 }
85 } |
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