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106
107 package com.Yasna.forum.database;
108
109 import java.util.Iterator  ;
110 import java.util.ListIterator ;
111 import java.util.ArrayList ;
112 import java.sql.*;
113 import com.Yasna.forum.*;
114
115
119 public class DbUserIterator implements Iterator , ListIterator {
120
121
122 private static final String ALL_USERS =
123 "SELECT userID from yazdUser";
124
125 private int currentIndex = -1;
126 private int [] users;
127
128 private ProfileManager profileManager;
129
130 protected DbUserIterator(ProfileManager profileManager) {
131 this.profileManager = profileManager;
132 ArrayList tempUsers = new ArrayList ();
135 Connection con = null;
136 PreparedStatement pstmt = null;
137 try {
138 con = DbConnectionManager.getConnection();
139 pstmt = con.prepareStatement(ALL_USERS);
140 ResultSet rs = pstmt.executeQuery();
141 while (rs.next()) {
142 tempUsers.add(new Integer (rs.getInt("userID")));
143 }
144 }
145 catch( SQLException sqle ) {
146 System.err.println("Error in DbUserIterator:constructor()-" + sqle);
147 }
148 finally {
149 try { pstmt.close(); }
150 catch (Exception e) { e.printStackTrace(); }
151 try { con.close(); }
152 catch (Exception e) { e.printStackTrace(); }
153 }
154 users = new int[tempUsers.size()];
156 for (int i=0; i<users.length; i++) {
157 users[i] = ((Integer )tempUsers.get(i)).intValue();
158 }
159 }
160
161 protected DbUserIterator(ProfileManager profileManager, int startIndex,
162 int numResults)
163 {
164 this.profileManager = profileManager;
165
166 int[] tempUsers = new int[numResults];
167 int userCount = 0;
171
172 Connection con = null;
173 PreparedStatement pstmt = null;
174
175 try {
176 con = DbConnectionManager.getConnection();
177 pstmt = con.prepareStatement(ALL_USERS);
178 ResultSet rs = pstmt.executeQuery();
179 for (int i=0; i<startIndex; i++) {
181 rs.next();
182 }
183 for (int i=0; i<numResults; i++) {
185 if (rs.next()) {
186 tempUsers[userCount] = rs.getInt("userID");
187 userCount++;
188 }
189 else {
190 break;
191 }
192 }
193 }
194 catch( SQLException sqle ) {
195 System.err.println("Error in DbUserIterator:constructor()-" + sqle);
196 }
197 finally {
198 try { pstmt.close(); }
199 catch (Exception e) { e.printStackTrace(); }
200 try { con.close(); }
201 catch (Exception e) { e.printStackTrace(); }
202 }
203 users = new int[userCount];
204 for (int i=0; i<userCount; i++) {
205 users[i] = tempUsers[i];
206 }
207 }
208
209
212 public boolean hasNext() {
213 return (currentIndex+1 < users.length);
214 }
215
216
219 public boolean hasPrevious() {
220 return (currentIndex > 0);
221 }
222
223
229 public Object next() throws java.util.NoSuchElementException {
230 User user = null;
231 currentIndex++;
232 if (currentIndex >= users.length) {
233 throw new java.util.NoSuchElementException ();
234 }
235 try {
236 user = profileManager.getUser(users[currentIndex]);
237 }
238 catch (UserNotFoundException gnfe) {
239 gnfe.printStackTrace();
240 }
241 return user;
242 }
243
244
250 public void add(Object o) throws UnsupportedOperationException {
251 throw new UnsupportedOperationException ();
252 }
253
254
260 public void remove() {
261 throw new UnsupportedOperationException ();
262 }
263
264
270 public void set(Object o) throws UnsupportedOperationException {
271 throw new UnsupportedOperationException ();
272 }
273
274
277 public int nextIndex() {
278 return currentIndex+1;
279 }
280
281
284 public Object previous() throws java.util.NoSuchElementException {
285 User user = null;
286 currentIndex--;
287 if (currentIndex < 0) {
288 currentIndex++;
289 throw new java.util.NoSuchElementException ();
290 }
291 try {
292 user = profileManager.getUser(users[currentIndex]);
293 }
294 catch (UserNotFoundException gnfe) {
295 System.err.println(gnfe);
296 }
297 return user;
298 }
299
300
303 public int previousIndex() {
304 return currentIndex-1;
305 }
306 }
307 |
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