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54
106
107 package com.Yasna.forum.database;
108
109 import java.util.*;
110 import java.sql.*;
112
113 import com.Yasna.util.*;
114 import com.Yasna.forum.*;
115
116
124 public class DbForumIterator implements Iterator, ListIterator {
125
126
127 private static final String  GET_THREADS_SORT_BY_CREATION_DATE =
128 "SELECT threadID, creationDate FROM yazdThread WHERE forumID=? " +
129 "ORDER BY sticky desc,creationDate DESC";
130 private static final String GET_THREADS_SORT_BY_MODIFIED_DATE =
131 "SELECT threadID, modifiedDate FROM yazdThread WHERE forumID=? " +
132 "ORDER BY sticky desc,modifiedDate DESC";
133
134 private DbForum forum;
137 private int [] threads;
139 private int currentIndex = -1;
141
142 DbForumFactory factory;
143
144 public DbForumIterator(DbForum forum, DbForumFactory factory)
145 {
146 this.forum = forum;
147 this.factory = factory;
148 ArrayList tempThreads = new ArrayList();
151 Connection con = null;
152 PreparedStatement pstmt = null;
153 try {
154 con = DbConnectionManager.getConnection();
155 pstmt = con.prepareStatement(GET_THREADS_SORT_BY_CREATION_DATE);
156 pstmt.setInt(1,forum.getID());
157 ResultSet rs = pstmt.executeQuery();
158
159 while (rs.next()) {
160 tempThreads.add(new Integer (rs.getInt("threadID")));
161 }
162 }
163 catch( SQLException sqle ) {
164 System.err.println("Error in DbThreadIterator:constructor()-" + sqle);
165 }
166 finally {
167 try { pstmt.close(); }
168 catch (Exception e) { e.printStackTrace(); }
169 try { con.close(); }
170 catch (Exception e) { e.printStackTrace(); }
171 }
172 threads = new int[tempThreads.size()];
173 for (int i=0; i<threads.length; i++) {
174 threads[i] = ((Integer )tempThreads.get(i)).intValue();
175 }
176 }
177
178 public DbForumIterator(DbForum forum, DbForumFactory factory,
179 int startIndex, int numResults, int sortBy)
180 {
181 this.forum = forum;
182 this.factory = factory;
183
184 int[] tempThreads = new int[numResults];
185 int threadCount = 0;
189
190 Connection con = null;
191 PreparedStatement pstmt = null;
192 try {
193 con = DbConnectionManager.getConnection();
194 if (Forum.SORT_BY_CREATE_DATE==sortBy) {
195 pstmt = con.prepareStatement(GET_THREADS_SORT_BY_CREATION_DATE);
196 } else {
197 pstmt = con.prepareStatement(GET_THREADS_SORT_BY_MODIFIED_DATE);
198 }
199 pstmt.setInt(1,forum.getID());
200 ResultSet rs = pstmt.executeQuery();
201
202 for (int i=0; i<startIndex; i++) {
204 rs.next();
205 }
206 for (int i=0; i<numResults; i++) {
208 if (rs.next()) {
209 tempThreads[threadCount] = rs.getInt("threadID");
210 threadCount++;
211 }
212 else {
213 break;
214 }
215 }
216 }
217 catch( SQLException sqle ) {
218 System.err.println("Error in DbThreadIterator:constructor()-" + sqle);
219 }
220 finally {
221 try { pstmt.close(); }
222 catch (Exception e) { e.printStackTrace(); }
223 try { con.close(); }
224 catch (Exception e) { e.printStackTrace(); }
225 }
226 threads = new int[threadCount];
227 for (int i=0; i<threadCount; i++) {
228 threads[i] = tempThreads[i];
229 }
230 }
231
232 public void add(Object o) throws UnsupportedOperationException {
233 throw new UnsupportedOperationException ();
234 }
235
236 public boolean hasNext() {
237 return (currentIndex+1 < threads.length);
238 }
239
240 public boolean hasPrevious() {
241 return (currentIndex > 0);
242 }
243
244 public Object next() throws java.util.NoSuchElementException {
245 ForumThread thread = null;
246 currentIndex++;
247 if (currentIndex >= threads.length) {
248 currentIndex--;
249 throw new java.util.NoSuchElementException ();
250 }
251 try {
252 thread = forum.getThread(threads[currentIndex]);
253 }
254 catch (ForumThreadNotFoundException tnfe) {
255 System.err.println(tnfe);
256 }
257 return thread;
258 }
259
260 public int nextIndex() {
261 return currentIndex+1;
262 }
263
264 public Object previous() throws java.util.NoSuchElementException {
265 ForumThread thread = null;
266 currentIndex--;
267 if (currentIndex < 0) {
268 currentIndex++;
269 throw new java.util.NoSuchElementException ();
270 }
271 try {
272 thread = forum.getThread(threads[currentIndex]);
273 }
274 catch (ForumThreadNotFoundException tnfe) {
275 System.err.println(tnfe);
276 }
277 return thread;
278 }
279
280 public int previousIndex() {
281 return currentIndex-1;
282 }
283
284 public void remove() throws UnsupportedOperationException {
285 throw new UnsupportedOperationException ();
286 }
287
288 public void set(Object o) throws UnsupportedOperationException {
289 throw new UnsupportedOperationException ();
290 }
291 }
292 |
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