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18
19 package cowsultants.itracker.ejb.util;
20
21 import java.sql.*;
22 import java.rmi.*;
23 import java.util.*;
24 import javax.sql.*;
25 import javax.rmi.*;
26 import javax.naming.*;
27
28 import cowsultants.itracker.ejb.client.interfaces.*;
29 import cowsultants.itracker.ejb.client.util.*;
30
31 public class IDCache {
32 private static final String  ID_NAME = "idstore";
33 private static final String DEFAULT_TABLE_NAME = "IDSTORE";
34 private static final String DEFAULT_DATASOURCE = "DefaultDS";
35 private static final int DEFAULT_FIRST_ID = 0;
36 private static final int DEFAULT_GROUP_SIZE = 100;
37 private static IDCache generator = null;
38 private static HashMap idCache = new HashMap();
39
40 private static String dataSource;
41 private static String tableName;
42 private static int firstId;
43 private static int groupSize;
44
45 private IDCache() {
46 dataSource = DEFAULT_DATASOURCE;
47 tableName = DEFAULT_TABLE_NAME;
48 firstId = DEFAULT_FIRST_ID;
49 groupSize = DEFAULT_GROUP_SIZE;
50 }
51
52 private IDCache(Object scRef) {
53 try {
54 SystemConfigurationHome scHome = (SystemConfigurationHome) PortableRemoteObject.narrow(scRef, SystemConfigurationHome.class);
55 SystemConfiguration sc = scHome.create();
56
57 dataSource = sc.getProperty("default_ds", DEFAULT_DATASOURCE);
58 tableName = sc.getProperty("idcache_tablename", DEFAULT_TABLE_NAME);
59 firstId = sc.getIntegerProperty("idcache_firstid", DEFAULT_FIRST_ID);
60 groupSize = sc.getIntegerProperty("idcache_groupsize", DEFAULT_GROUP_SIZE);
61 } catch(Exception e) {
62 Logger.logError("ID Cache Initalization Error: " + e.getMessage());
63 dataSource = DEFAULT_DATASOURCE;
64 tableName = DEFAULT_TABLE_NAME;
65 firstId = DEFAULT_FIRST_ID;
66 groupSize = DEFAULT_GROUP_SIZE;
67 }
68
69 if(Logger.isLoggingDebug()) {
70 Logger.logDebug("IDCache Initialized: DataSource = '" + dataSource + "'");
71 Logger.logDebug("IDCache Initialized: TableName = '" + tableName + "'");
72 Logger.logDebug("IDCache Initialized: FirstID = '" + firstId + "'");
73 Logger.logDebug("IDCache Initialized: GroupSize = '" + groupSize + "'");
74 }
75 }
76
77 public static synchronized Integer getNextId(String idName) throws IDException {
78 return getNextId(idName, null);
79 }
80
81 public static synchronized Integer getNextId(String idName, Connection conn) throws IDException {
82 if(generator == null) {
83 generator = new IDCache();
84 }
85 IDCache.CacheValue cacheValue = (IDCache.CacheValue) idCache.get(idName);
86 if(cacheValue == null || cacheValue.maxId == cacheValue.lastId) {
87 getNextIdGroup(idName, conn);
88 cacheValue = (IDCache.CacheValue) idCache.get(idName);
89 }
90 cacheValue.lastId++;
91 idCache.put(idName, cacheValue);
92 return new Integer (cacheValue.lastId);
94 }
95
96 public static synchronized void initializeCache(Object scRef) {
97 if(generator == null) {
98 generator = new IDCache(scRef);
99 }
100 }
101
102 public static synchronized void resetCache() {
103 if(generator == null) {
104 generator = new IDCache();
105 }
106 idCache.clear();
107 }
108
109 public static synchronized void resetCache(String idName) {
110 if(generator == null) {
111 generator = new IDCache();
112 }
113 idCache.remove(idName);
114 }
115
116 public static synchronized void deleteCache(String idName) throws IDException {
117 if(generator == null) {
118 generator = new IDCache();
119 }
120
121 Connection conn = null;
122
123 try {
124 InitialContext ic = new InitialContext();
125 DataSource ds = (DataSource) ic.lookup(dataSource);
126 conn = ds.getConnection();
127
128 PreparedStatement pstmt = conn.prepareStatement("delete from " + getTableName() + " where name = ?");
129 pstmt.setString(1, idName.toLowerCase());
130 pstmt.executeUpdate();
131 pstmt.close();
132 } catch(NamingException ne) {
133 throw new IDException("Cannot locate Connection Pool: " + ne.getMessage());
134 } catch(SQLException sqle) {
135 throw new IDException("Database Error while deleting cache value: " + sqle.getMessage());
136 } finally {
137 try {
138 if(conn != null && ! conn.isClosed()) {
139 conn.close();
140 }
141 } catch(SQLException sqle) {
142 throw new IDException("Database Error while deleting cache value: " + sqle.getMessage());
143 }
144 }
145 }
146
147 public static String getTableName() {
148 return tableName;
149 }
150
151 public static int getFirstId() {
152 return firstId;
153 }
154
155 public static int getGroupSize() {
156 return groupSize;
157 }
158
159 private static synchronized void getNextIdGroup(String idName) throws IDException {
160 getNextIdGroup(idName, null);
161 }
162
163 private static synchronized void getNextIdGroup(String idName, Connection conn) throws IDException {
164 boolean closeConnection = false;
165 int lastId;
166 int nextId;
167
168 try {
169 if(conn == null) {
170 InitialContext ic = new InitialContext();
171 DataSource ds = (DataSource) ic.lookup(dataSource);
172 conn = ds.getConnection();
173 closeConnection = true;
174 }
175
176 Logger.logDebug("IDCache: Getting next id block from database.");
177
178 PreparedStatement pstmt = conn.prepareStatement("select last_id from " + getTableName() + " where name = ?");
179 pstmt.setString(1, idName.toLowerCase());
180 ResultSet rs = pstmt.executeQuery();
181 if(! rs.next()) {
182 pstmt.close();
183 createNewID(idName, conn);
184 } else {
185 try {
186 lastId = Integer.parseInt(rs.getString(1));
187 nextId = lastId + getGroupSize();
188 } catch(NumberFormatException nfe) {
189 throw new IDException("Invalid id in current table: " + rs.getString(1));
190 }
191 rs.close();
192 pstmt.close();
193
194 Logger.logDebug("IDCache: Next id block is from " + (lastId + 1) + " to " + nextId);
195
196 pstmt = conn.prepareStatement("update " + getTableName() + " set last_id = ? where name = ?");
197 pstmt.setString(1, Integer.toString(nextId));
198 pstmt.setString(2, idName);
199 int affectedRows = pstmt.executeUpdate();
200 pstmt.close();
201 if(affectedRows != 1) {
202 throw new IDException("Error incrementing id for " + idName);
203 }
204 IDCache.CacheValue cacheValue = generator.new CacheValue();
205 cacheValue.setValues(idName, lastId, nextId);
206 idCache.put(idName, cacheValue);
207 }
208 } catch(NamingException ne) {
209 throw new IDException("Cannot locate Connection Pool: " + ne.getMessage());
210 } catch(SQLException sqle) {
211 throw new IDException("Database Error while getting next id: " + sqle.getMessage());
212 } finally {
213 if(closeConnection) {
214 try {
215 if(conn != null && ! conn.isClosed()) {
216 conn.close();
217 }
218 } catch(SQLException sqle) {
219 throw new IDException("Database Error while getting next id: " + sqle.getMessage());
220 }
221 }
222 }
223 }
224
225 private static synchronized void createNewID(String idName, Connection conn) throws IDException {
226 Logger.logDebug("IDCache: Creating new id group " + idName);
227
228 try {
229 String nextId;
230 if(ID_NAME.equals(idName)) {
231 Logger.logWarn("Could not find " + ID_NAME + " entry in the " + getTableName() + " table. " +
232 "Creating new entry with value of 1.");
233 nextId = "1";
234 } else {
235 nextId = getNextId(ID_NAME, conn).toString();
236 }
237
238 PreparedStatement pstmt = conn.prepareStatement("insert into " + getTableName() + " (id, name, last_id) values (?, ?, ?)");
239 pstmt.setString(1, nextId);
240 pstmt.setString(2, idName.toLowerCase());
241 pstmt.setString(3, Integer.toString(getFirstId() + getGroupSize()));
242
243 pstmt.executeUpdate();
244 pstmt.close();
245
246 IDCache.CacheValue cacheValue = generator.new CacheValue();
247 cacheValue.setValues(idName, getFirstId(), getFirstId() + getGroupSize());
248 idCache.put(idName, cacheValue);
249 } catch(SQLException sqle) {
250 throw new IDException("Database Error while creating new id: " + sqle.getMessage());
251 }
252 }
253
254 private class CacheValue {
255 private IDCache container;
256 public String name;
257 public int lastId;
258 public int maxId;
259
260 public void CacheValue(IDCache generator) {
261 container = generator;
262 }
263
264 public void setValues(String nameIn, int lastIdIn, int maxIdIn) {
265 name = nameIn;
266 lastId = lastIdIn;
267 maxId = maxIdIn;
268 }
269 }
270
271
272 }
273
274 |
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