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 the com.oreilly.servlet library, any library
22 * licensed under the Apache Software License, The Sun (tm) Java Advanced
23 * Imaging library (JAI), The Sun JIMI library (or with modified versions of
24 * the above that use the same license as the above), and distribute linked
25 * combinations including the two. You must obey the GNU General Public
26 * License in all respects for all of the code used other than the above
27 * mentioned libraries. If you modify this file, you may extend this exception
28 * to your version of the file, but you are not obligated to do so. If you do
29 * not wish to do so, delete this exception statement from your version.
36 import mir.storage.*;
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37 import mir.entity.*;
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39 public class EntityBrowser implements RewindableIterator {
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41 private StorageObject storage;
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42 private String whereClause;
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43 private String orderByClause;
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44 private int batchSize;
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45 private int toFetch;
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46 private EntityList currentBatch;
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51 private int batchPosition;
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52 private int positionInBatch;
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54 public EntityBrowser(StorageObject aStorage, String aWhereClause, String anOrderByClause,
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55 int aBatchSize, int aLimit, int aSkip) throws StorageObjectException {
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58 whereClause=aWhereClause;
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59 orderByClause=anOrderByClause;
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60 batchSize=aBatchSize;
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67 public EntityBrowser(StorageObject aStorage,
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68 String aWhereClause, String anOrderByClause,
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69 int aBatchSize) throws StorageObjectException {
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70 this(aStorage, aWhereClause, anOrderByClause, aBatchSize, -1, 0);
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73 public void readCurrentBatch(int aSkip) throws StorageObjectException {
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74 currentBatch = storage.selectByWhereClause(whereClause, orderByClause, aSkip, batchSize);
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75 batchPosition = aSkip;
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76 positionInBatch = 0;
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79 public void rewind() {
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81 readCurrentBatch(skip);
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83 catch (Throwable t) {
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84 throw new RuntimeException(t.getMessage());
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88 public boolean hasNext() {
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90 if (limit>-1 && batchPosition+positionInBatch>=skip+limit)
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93 if (positionInBatch>=currentBatch.size() && currentBatch.hasNextBatch()) {
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94 readCurrentBatch(batchPosition+positionInBatch);
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97 return (positionInBatch<currentBatch.size());
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99 catch (Throwable t) {
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100 throw new RuntimeException(t.getMessage());
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104 public Object next() {
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107 Entity result = currentBatch.elementAt(positionInBatch);
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108 positionInBatch=positionInBatch+1;
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116 catch (Throwable t) {
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117 throw new RuntimeException(t.getMessage());
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121 public void remove() {
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122 throw new UnsupportedOperationException();
\r