root / branches / v2_0_0_prep / libraries / libFMap_dataDB / src / org / gvsig / fmap / data / feature / db / jdbc / AbstractJDBCIterator.java @ 23680
History | View | Annotate | Download (6 KB)
| 1 |
/* gvSIG. Geographic Information System of the Valencian Government
|
|---|---|
| 2 |
*
|
| 3 |
* Copyright (C) 2007-2008 Infrastructures and Transports Department
|
| 4 |
* of the Valencian Government (CIT)
|
| 5 |
*
|
| 6 |
* This program is free software; you can redistribute it and/or
|
| 7 |
* modify it under the terms of the GNU General Public License
|
| 8 |
* as published by the Free Software Foundation; either version 2
|
| 9 |
* of the License, or (at your option) any later version.
|
| 10 |
*
|
| 11 |
* This program 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.
|
| 15 |
*
|
| 16 |
* You should have received a copy of the GNU General Public License
|
| 17 |
* along with this program; if not, write to the Free Software
|
| 18 |
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
|
| 19 |
* MA 02110-1301, USA.
|
| 20 |
*
|
| 21 |
*/
|
| 22 |
|
| 23 |
/*
|
| 24 |
* AUTHORS (In addition to CIT):
|
| 25 |
* 2008 IVER T.I. S.A. {{Task}}
|
| 26 |
*/
|
| 27 |
|
| 28 |
package org.gvsig.fmap.data.feature.db.jdbc; |
| 29 |
|
| 30 |
import java.sql.Connection; |
| 31 |
import java.sql.ResultSet; |
| 32 |
import java.sql.Statement; |
| 33 |
import java.util.Iterator; |
| 34 |
import java.util.NoSuchElementException; |
| 35 |
|
| 36 |
import org.gvsig.fmap.data.ReadException; |
| 37 |
import org.gvsig.fmap.data.feature.Feature; |
| 38 |
import org.gvsig.fmap.data.feature.FeatureManager; |
| 39 |
import org.gvsig.fmap.data.feature.db.DBFeatureType; |
| 40 |
import org.gvsig.fmap.data.feature.expressionevaluator.Filter; |
| 41 |
|
| 42 |
public abstract class AbstractJDBCIterator implements Iterator { |
| 43 |
|
| 44 |
protected boolean nextChecked = false; |
| 45 |
protected Feature feature;
|
| 46 |
protected ResultSet rs; |
| 47 |
protected JDBCStore store;
|
| 48 |
protected DBFeatureType featureType;
|
| 49 |
protected boolean rsEOF = false; |
| 50 |
protected boolean memoryEOF = false; |
| 51 |
protected int memoryPosition = 0; |
| 52 |
protected int fetchSize; |
| 53 |
protected String sql; |
| 54 |
protected int page; |
| 55 |
protected int index; |
| 56 |
protected FeatureManager featureManager = null; |
| 57 |
protected Filter featureFilter = null; |
| 58 |
|
| 59 |
private int initialPosition = 1; |
| 60 |
|
| 61 |
public AbstractJDBCIterator(JDBCStore store, DBFeatureType featureType,
|
| 62 |
String sql, int fetchSize, FeatureManager featureManager, |
| 63 |
Filter featureFilter, int initialPosition) throws ReadException { |
| 64 |
this.store = store;
|
| 65 |
this.featureType = featureType;
|
| 66 |
this.fetchSize = fetchSize;
|
| 67 |
this.sql = sql;
|
| 68 |
this.page = 0; |
| 69 |
this.index = 0; |
| 70 |
this.featureManager = featureManager;
|
| 71 |
this.featureFilter = featureFilter;
|
| 72 |
this.initialPosition = initialPosition;
|
| 73 |
this.createResulset();
|
| 74 |
} |
| 75 |
|
| 76 |
public AbstractJDBCIterator(JDBCStore store, DBFeatureType featureType,
|
| 77 |
String sql, int fetchSize, FeatureManager featureManager, |
| 78 |
Filter featureFilter) throws ReadException { |
| 79 |
this(store, featureType, sql, fetchSize, featureManager, featureFilter,
|
| 80 |
1);
|
| 81 |
} |
| 82 |
|
| 83 |
protected Feature nextDBFeature() {
|
| 84 |
Feature feature = null;
|
| 85 |
while (true) { |
| 86 |
try {
|
| 87 |
if (rs.next()) {
|
| 88 |
feature = this.createFeatureFromTheResulset();
|
| 89 |
this.index++;
|
| 90 |
return feature;
|
| 91 |
} else {
|
| 92 |
if (this.index == this.fetchSize) { |
| 93 |
this.index = 0; |
| 94 |
this.page++;
|
| 95 |
this.createResulset();
|
| 96 |
continue;
|
| 97 |
} else {
|
| 98 |
return null; |
| 99 |
} |
| 100 |
|
| 101 |
} |
| 102 |
} catch (java.sql.SQLException e) {
|
| 103 |
throw new RuntimeException(new ReadException(this.store |
| 104 |
.getName(), e)); |
| 105 |
} catch (ReadException e) {
|
| 106 |
throw new RuntimeException(e); |
| 107 |
} |
| 108 |
} |
| 109 |
} |
| 110 |
|
| 111 |
protected Feature nextMemoryFeature() {
|
| 112 |
Feature feature = null;
|
| 113 |
while (true) { |
| 114 |
if (this.memoryPosition < this.featureManager.getNum()) { |
| 115 |
try {
|
| 116 |
feature = featureManager.getFeature(this.memoryPosition,
|
| 117 |
store, this.featureType);
|
| 118 |
this.memoryPosition++;
|
| 119 |
if (this.featureFilter == null) { |
| 120 |
break;
|
| 121 |
} |
| 122 |
if (!this.featureFilter.evaluate(feature)) { |
| 123 |
continue;
|
| 124 |
} |
| 125 |
} catch (ReadException e) {
|
| 126 |
throw new RuntimeException(new ReadException(this.store |
| 127 |
.getName(), e)); |
| 128 |
} |
| 129 |
} else {
|
| 130 |
this.memoryEOF = true; |
| 131 |
break;
|
| 132 |
} |
| 133 |
} |
| 134 |
return feature;
|
| 135 |
} |
| 136 |
|
| 137 |
protected abstract Feature createFeatureFromTheResulset() |
| 138 |
throws ReadException;
|
| 139 |
|
| 140 |
protected abstract void checkModified(); |
| 141 |
|
| 142 |
protected abstract Connection getConnection() throws ReadException; |
| 143 |
|
| 144 |
protected abstract String getFinalResulsetSQL(); |
| 145 |
|
| 146 |
protected void createResulset() throws ReadException { |
| 147 |
String mSql = this.getFinalResulsetSQL(); |
| 148 |
Connection conn = this.getConnection(); |
| 149 |
try {
|
| 150 |
if (this.rs != null) { |
| 151 |
this.rs.close();
|
| 152 |
} |
| 153 |
|
| 154 |
Statement st = conn.createStatement(ResultSet.TYPE_FORWARD_ONLY, |
| 155 |
ResultSet.CONCUR_READ_ONLY);
|
| 156 |
this.rs = st.executeQuery(mSql);
|
| 157 |
|
| 158 |
if (initialPosition > 1) { |
| 159 |
rs.absolute(initialPosition); |
| 160 |
} |
| 161 |
|
| 162 |
} catch (java.sql.SQLException e) {
|
| 163 |
throw new SQLException(mSql, this.store.getName(), e); |
| 164 |
} |
| 165 |
|
| 166 |
} |
| 167 |
|
| 168 |
|
| 169 |
public boolean hasNext() { |
| 170 |
checkModified(); |
| 171 |
|
| 172 |
if (nextChecked) {
|
| 173 |
return this.feature != null; |
| 174 |
} |
| 175 |
Feature feature = null;
|
| 176 |
nextChecked = true;
|
| 177 |
if (this.rsEOF && this.memoryEOF) { |
| 178 |
return false; |
| 179 |
} |
| 180 |
while (true) { |
| 181 |
try {
|
| 182 |
if (!this.rsEOF) { |
| 183 |
feature = nextDBFeature(); |
| 184 |
if (feature == null) { |
| 185 |
this.close();
|
| 186 |
continue;
|
| 187 |
} |
| 188 |
if (this.featureManager != null |
| 189 |
&& this.featureManager.isDeleted(feature)) {
|
| 190 |
continue;
|
| 191 |
} |
| 192 |
this.feature = feature;
|
| 193 |
return true; |
| 194 |
} else {
|
| 195 |
if (this.featureManager == null) { |
| 196 |
this.memoryEOF = true; |
| 197 |
return false; |
| 198 |
} |
| 199 |
this.feature = nextMemoryFeature();
|
| 200 |
return this.feature != null; |
| 201 |
} |
| 202 |
} catch (java.sql.SQLException e) {
|
| 203 |
throw new RuntimeException(new ReadException(this.store |
| 204 |
.getName(), e)); |
| 205 |
} |
| 206 |
} |
| 207 |
} |
| 208 |
|
| 209 |
public Object next() { |
| 210 |
checkModified(); |
| 211 |
if (!nextChecked) {
|
| 212 |
hasNext(); |
| 213 |
} |
| 214 |
if (this.feature == null) { |
| 215 |
throw new NoSuchElementException(); |
| 216 |
} |
| 217 |
nextChecked = false;
|
| 218 |
Feature feature = this.feature;
|
| 219 |
this.feature = null; |
| 220 |
return feature;
|
| 221 |
} |
| 222 |
|
| 223 |
public void remove() { |
| 224 |
throw new UnsupportedOperationException(); |
| 225 |
} |
| 226 |
|
| 227 |
protected void close() throws java.sql.SQLException { |
| 228 |
if (rs == null) { |
| 229 |
return;
|
| 230 |
} |
| 231 |
rs.close(); |
| 232 |
this.rsEOF = true; |
| 233 |
} |
| 234 |
} |