2 * Copyright (C) 2001, 2002 The Mir-coders group
4 * This file is part of Mir.
6 * Mir is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * Mir is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with Mir; if not, write to the Free Software
18 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 * In addition, as a special exception, The Mir-coders gives permission to link
21 * the code of this program with any library licensed under the Apache Software License,
22 * The Sun (tm) Java Advanced Imaging library (JAI), The Sun JIMI library
23 * (or with modified versions of the above that use the same license as the above),
24 * and distribute linked combinations including the two. You must obey the
25 * GNU General Public License in all respects for all of the code used other than
26 * the above mentioned libraries. If you modify this file, you may extend this
27 * exception to your version of the file, but you are not obligated to do so.
28 * If you do not wish to do so, delete this exception statement from your version.
33 import mir.storage.StorageObject;
34 import mir.storage.StorageObjectFailure;
35 import mir.util.RewindableIterator;
37 public class EntityBrowser implements RewindableIterator {
39 private StorageObject storage;
40 private String whereClause;
41 private String orderByClause;
42 private int batchSize;
44 private EntityList currentBatch;
49 private int batchPosition;
50 private int positionInBatch;
52 public EntityBrowser(StorageObject aStorage, String aWhereClause, String anOrderByClause,
53 int aBatchSize, int aLimit, int aSkip) throws StorageObjectFailure {
56 whereClause=aWhereClause;
57 orderByClause=anOrderByClause;
65 public EntityBrowser(StorageObject aStorage,
66 String aWhereClause, String anOrderByClause,
67 int aBatchSize) throws StorageObjectFailure {
68 this(aStorage, aWhereClause, anOrderByClause, aBatchSize, -1, 0);
71 public void readCurrentBatch(int aSkip) throws StorageObjectFailure {
72 currentBatch = storage.selectByWhereClause(whereClause, orderByClause, aSkip, batchSize);
73 batchPosition = aSkip;
77 public void rewind() {
79 readCurrentBatch(skip);
82 throw new RuntimeException(t.getMessage());
86 public boolean hasNext() {
88 if (limit>-1 && batchPosition+positionInBatch>=skip+limit)
91 if (positionInBatch>=currentBatch.size() && currentBatch.hasNextBatch()) {
92 readCurrentBatch(batchPosition+positionInBatch);
95 return (positionInBatch<currentBatch.size());
98 throw new RuntimeException(t.getMessage());
102 public Object next() {
105 Entity result = currentBatch.elementAt(positionInBatch);
106 positionInBatch=positionInBatch+1;
114 catch (Throwable t) {
115 throw new RuntimeException(t.getMessage());
119 public void remove() {
120 throw new UnsupportedOperationException();