| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| AbstractPoemApp |
|
| 3.0;3 | ||||
| AbstractPoemApp$1 |
|
| 3.0;3 |
| 1 | /* | |
| 2 | * $Source: /usr/cvsroot/melati/melati/src/site/resources/withWebmacro/org.melati.app.AbstractPoemApp.html,v $ | |
| 3 | * $Revision: 1.1 $ | |
| 4 | * | |
| 5 | * Copyright (C) 2005 Tim Pizey | |
| 6 | * | |
| 7 | * Part of Melati (http://melati.org), a framework for the rapid | |
| 8 | * development of clean, maintainable web applications. | |
| 9 | * | |
| 10 | * Melati is free software; Permission is granted to copy, distribute | |
| 11 | * and/or modify this software under the terms either: | |
| 12 | * | |
| 13 | * a) the GNU General Public License as published by the Free Software | |
| 14 | * Foundation; either version 2 of the License, or (at your option) | |
| 15 | * any later version, | |
| 16 | * | |
| 17 | * or | |
| 18 | * | |
| 19 | * b) any version of the Melati Software License, as published | |
| 20 | * at http://melati.org | |
| 21 | * | |
| 22 | * You should have received a copy of the GNU General Public License and | |
| 23 | * the Melati Software License along with this program; | |
| 24 | * if not, write to the Free Software Foundation, Inc., | |
| 25 | * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the | |
| 26 | * GNU General Public License and visit http://melati.org to obtain the | |
| 27 | * Melati Software License. | |
| 28 | * | |
| 29 | * Feel free to contact the Developers of Melati (http://melati.org), | |
| 30 | * if you would like to work out a different arrangement than the options | |
| 31 | * outlined here. It is our intention to allow Melati to be used by as | |
| 32 | * wide an audience as possible. | |
| 33 | * | |
| 34 | * This program is distributed in the hope that it will be useful, | |
| 35 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
| 36 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
| 37 | * GNU General Public License for more details. | |
| 38 | * | |
| 39 | * Contact details for copyright holder: | |
| 40 | * | |
| 41 | * Tim Pizey <timp At paneris.org> | |
| 42 | * http://paneris.org/~timp | |
| 43 | */ | |
| 44 | ||
| 45 | package org.melati.app; | |
| 46 | ||
| 47 | ||
| 48 | import java.io.IOException; | |
| 49 | ||
| 50 | import org.melati.Melati; | |
| 51 | import org.melati.PoemContext; | |
| 52 | import org.melati.poem.AccessPoemException; | |
| 53 | import org.melati.poem.PoemDatabaseFactory; | |
| 54 | import org.melati.poem.PoemThread; | |
| 55 | import org.melati.poem.PoemTask; | |
| 56 | import org.melati.poem.AccessToken; | |
| 57 | import org.melati.poem.util.ArrayUtils; | |
| 58 | import org.melati.util.ConfigException; | |
| 59 | import org.melati.util.MelatiException; | |
| 60 | import org.melati.util.UnexpectedExceptionException; | |
| 61 | ||
| 62 | /** | |
| 63 | * Base class to use Poem as an application. | |
| 64 | * | |
| 65 | * <p> | |
| 66 | * Simply extend this class and override the {@link #doPoemRequest} method. | |
| 67 | * If you are going to use a template engine look at {@link AbstractTemplateApp}. | |
| 68 | * </p> | |
| 69 | * | |
| 70 | * <UL> | |
| 71 | * <LI> | |
| 72 | * The command line arguments are expected in the following order: | |
| 73 | * <BLOCKQUOTE><TT> | |
| 74 | * <BR>db | |
| 75 | * <BR>db method | |
| 76 | * <BR>db table method | |
| 77 | * <BR>db table troid method | |
| 78 | * </TT></BLOCKQUOTE> | |
| 79 | * | |
| 80 | * these components are broken out of the command line arguments and passed to | |
| 81 | * your application code in the {@link Melati} parameter. | |
| 82 | * | |
| 83 | * <TABLE> | |
| 84 | * <TR> | |
| 85 | * <TD><TT><I>db</I></TT></TD> | |
| 86 | * <TD> | |
| 87 | * The first argument is taken to be the `logical name' | |
| 88 | * of the POEM database to which the servlet should connect. It | |
| 89 | * is mapped onto JDBC connection details via the config file | |
| 90 | * <TT>org.melati.LogicalDatabase.properties</TT>, of which there is an | |
| 91 | * example in the source tree. This is automatically made available in | |
| 92 | * templates as <TT>$melati.Database</TT>. | |
| 93 | * </TD> | |
| 94 | * <TR> | |
| 95 | * <TD><TT><I>table</I></TT></TD> | |
| 96 | * <TD> | |
| 97 | * The name of a table to work on: | |
| 98 | * perhaps it is meant to list its contents. This is automatically | |
| 99 | * made available in templates as <TT>$melati.Table</TT>. | |
| 100 | * </TD> | |
| 101 | * </TR> | |
| 102 | * <TR> | |
| 103 | * <TD><TT><I>troid</I></TT></TD> | |
| 104 | * <TD> | |
| 105 | * The POEM `troid' (table row identifier, or row-unique integer) of a | |
| 106 | * row within a <TT><I>table</I></TT>. | |
| 107 | * This is automatically made | |
| 108 | * available in templates as <TT>$melati.Object</TT>. | |
| 109 | * </TD> | |
| 110 | * </TR> | |
| 111 | * <TR> | |
| 112 | * <TD><TT><I>method</I></TT></TD> | |
| 113 | * <TD> | |
| 114 | * A freeform string telling your servlet what it is meant to do. This | |
| 115 | * is automatically made available in templates as | |
| 116 | * <TT>$melati.Method</TT>. | |
| 117 | * </TD> | |
| 118 | * </TR> | |
| 119 | * </TABLE> | |
| 120 | * | |
| 121 | * <LI> | |
| 122 | * You can change the way these things are determined by overriding | |
| 123 | * {@link #poemContext}. | |
| 124 | * | |
| 125 | * <LI> | |
| 126 | * Any POEM database operations you perform will be done with the access | |
| 127 | * rights of the POEM <TT>User</TT> associated with the POEM session. If | |
| 128 | * there is no established session, the current user will be set to | |
| 129 | * the default `guest' user. If this method terminates with an | |
| 130 | * <TT>AccessPoemException</TT>, indicating that you have attempted something | |
| 131 | * which you aren't entitled to do, the user will be prompted to log in, and | |
| 132 | * the original request will be retried. The precise mechanism used for | |
| 133 | * login is <A HREF=#loginmechanism>configurable</A>. | |
| 134 | * | |
| 135 | * <LI> | |
| 136 | * No changes made to the database by other concurrently executing threads | |
| 137 | * will be visible to you (in the sense that once you have seen a particular | |
| 138 | * version of a record, you will always subsequently see the same one), and | |
| 139 | * your own changes will not be made permanent until this method completes | |
| 140 | * successfully or you perform an explicit <TT>PoemThread.commit()</TT>. If | |
| 141 | * it terminates with an exception or you issue a | |
| 142 | * <TT>PoemThread.rollback()</TT>, your changes will be lost. | |
| 143 | * | |
| 144 | * <LI> | |
| 145 | * <A NAME=loginmechanism></A>It is possible to configure how your | |
| 146 | * <TT>PoemApp</TT>-derived applications implement user login. If the | |
| 147 | * properties file <TT>org.melati.MelatiApp.properties</TT> | |
| 148 | * exists and contains a setting | |
| 149 | * <TT>org.melati.MelatiApp.accessHandler=<I>foo</I></TT>, then | |
| 150 | * <TT><I>foo</I></TT> is taken to be the name of a class implementing the | |
| 151 | * <TT>AccessHandler</TT> interface. | |
| 152 | * </UL> | |
| 153 | * | |
| 154 | * If you do not need access handling then set your accessHandler to | |
| 155 | * <tt>org.melati.login.OpenAccessHandler</tt>. | |
| 156 | * If you do need access handling then set your accessHandler to | |
| 157 | * <tt>org.melati.login.CommandLineAccessHandler</tt>. | |
| 158 | * However this is not extremely secure, as the user could potentially | |
| 159 | * change this seting to <tt>OpenAccessHandler</tt> as they are on the same machine. | |
| 160 | * | |
| 161 | * You can specify the username and password to use by adding command line parameters: | |
| 162 | * <pre> | |
| 163 | * <tt>-username user -password password</tt> | |
| 164 | * </pre> | |
| 165 | * | |
| 166 | * | |
| 167 | * @see org.melati.poem.Database#guestAccessToken | |
| 168 | * @see org.melati.poem.PoemThread#commit | |
| 169 | * @see org.melati.poem.PoemThread#rollback | |
| 170 | * @see #poemContext | |
| 171 | * @see org.melati.login.AccessHandler | |
| 172 | * @see org.melati.login.HttpSessionAccessHandler | |
| 173 | * @see org.melati.login.Login | |
| 174 | * @see org.melati.login.OpenAccessHandler | |
| 175 | * @see org.melati.login.CommandLineAccessHandler | |
| 176 | */ | |
| 177 | ||
| 178 | 100 | public abstract class AbstractPoemApp extends AbstractConfigApp implements App { |
| 179 | ||
| 180 | 2 | private static Boolean taskPerformedOrLoggedInAndTaskAttempted = Boolean.FALSE; |
| 181 | ||
| 182 | /** | |
| 183 | * Initialise. | |
| 184 | * | |
| 185 | * @param args the command line arguments | |
| 186 | * @return a configured Melati | |
| 187 | * {@inheritDoc} | |
| 188 | * @see org.melati.app.AbstractConfigApp#init(java.lang.String[]) | |
| 189 | */ | |
| 190 | public Melati init(String[] args) throws MelatiException { | |
| 191 | 56 | Melati m = super.init(args); |
| 192 | 54 | if (m.getDatabase() == null) { |
| 193 | try { | |
| 194 | 2 | super.term(m); |
| 195 | 0 | } catch (IOException e) { |
| 196 | 0 | e = null; |
| 197 | 2 | } |
| 198 | 2 | throw new ConfigException("No database configured"); |
| 199 | } | |
| 200 | 52 | return m; |
| 201 | } | |
| 202 | ||
| 203 | /** | |
| 204 | * Clean up at end of run. | |
| 205 | * | |
| 206 | * @param melati the melati | |
| 207 | * @throws IOException | |
| 208 | */ | |
| 209 | public void term(Melati melati) throws IOException { | |
| 210 | 56 | super.term(melati); |
| 211 | 56 | if (melati.getDatabase() != null) |
| 212 | 56 | PoemDatabaseFactory.disconnectDatabase(melati.getDatabase().getName()); |
| 213 | 56 | } |
| 214 | ||
| 215 | /** | |
| 216 | * A place holder for things you might want to do before | |
| 217 | * setting up a <code>PoemSession</code>. | |
| 218 | * | |
| 219 | * @param melati the current Melati | |
| 220 | * @throws Exception if anything goes wrong | |
| 221 | */ | |
| 222 | protected void prePoemSession(Melati melati) throws Exception { | |
| 223 | 44 | Melati foolEclipse = melati; |
| 224 | 44 | melati = foolEclipse; |
| 225 | 44 | } |
| 226 | ||
| 227 | protected void doConfiguredRequest(final Melati melati) { | |
| 228 | // Do something outside of the PoemSession | |
| 229 | try { | |
| 230 | 46 | melati.getConfig().getAccessHandler().buildRequest(melati); |
| 231 | 46 | prePoemSession(melati); |
| 232 | 2 | } catch (Exception e) { |
| 233 | 2 | throw new UnexpectedExceptionException(e); |
| 234 | 44 | } |
| 235 | ||
| 236 | // Login loop | |
| 237 | // If not logged-in when required then an exception is thrown. | |
| 238 | // The exception is handled and the task revisited | |
| 239 | // The flag is reset to allow this to be run again. | |
| 240 | 44 | synchronized(taskPerformedOrLoggedInAndTaskAttempted) { |
| 241 | 44 | taskPerformedOrLoggedInAndTaskAttempted = Boolean.FALSE; |
| 242 | //int goes = 0; | |
| 243 | 84 | while (taskPerformedOrLoggedInAndTaskAttempted.equals(Boolean.FALSE)) { |
| 244 | //goes ++; | |
| 245 | //if (goes > 2) | |
| 246 | // throw new MelatiBugMelatiException("Problem with login loop logic, goes = " + goes); | |
| 247 | 48 | melati.getDatabase().inSession ( |
| 248 | 48 | AccessToken.root, new PoemTask() { |
| 249 | public void run () { | |
| 250 | 48 | melati.getConfig().getAccessHandler().establishUser(melati); |
| 251 | 48 | melati.loadTableAndObject(); |
| 252 | try { | |
| 253 | try { | |
| 254 | 48 | doPoemRequest(melati); |
| 255 | 36 | taskPerformedOrLoggedInAndTaskAttempted = Boolean.TRUE; |
| 256 | 12 | } catch (Exception e) { |
| 257 | 12 | _handleException (melati, e); |
| 258 | 36 | } |
| 259 | 8 | } catch (Exception e) { |
| 260 | 8 | taskPerformedOrLoggedInAndTaskAttempted = Boolean.TRUE; |
| 261 | try { | |
| 262 | 8 | term(melati); |
| 263 | 0 | } catch (IOException e1) { |
| 264 | 0 | e1 = null; |
| 265 | 8 | } |
| 266 | 8 | throw new UnhandledExceptionException(e); |
| 267 | 40 | } |
| 268 | 40 | } |
| 269 | ||
| 270 | // Not sure there is any point in this | |
| 271 | // Cannot find a way of accessing it | |
| 272 | //public String toString() { | |
| 273 | // return "PoemApp"; | |
| 274 | //} | |
| 275 | } | |
| 276 | ); | |
| 277 | } | |
| 278 | 36 | } |
| 279 | 36 | } |
| 280 | ||
| 281 | /** | |
| 282 | * Default method to handle an exception. | |
| 283 | * | |
| 284 | * @param melati the Melati | |
| 285 | * @param exception the exception to handle | |
| 286 | */ | |
| 287 | protected static void handleException(Melati melati, Exception exception) | |
| 288 | throws Exception { | |
| 289 | ||
| 290 | 12 | if (exception instanceof AccessPoemException) { |
| 291 | 10 | melati.getConfig().getAccessHandler() |
| 292 | .handleAccessException(melati,(AccessPoemException)exception); | |
| 293 | ||
| 294 | } | |
| 295 | else | |
| 296 | 2 | throw exception; |
| 297 | 4 | } |
| 298 | ||
| 299 | protected final void _handleException(Melati melati, Exception exception) | |
| 300 | throws Exception { | |
| 301 | try { | |
| 302 | 12 | handleException(melati, exception); |
| 303 | } | |
| 304 | 8 | catch (Exception e) { |
| 305 | 8 | PoemThread.rollback(); |
| 306 | 8 | throw e; |
| 307 | 4 | } |
| 308 | 4 | } |
| 309 | ||
| 310 | ||
| 311 | protected PoemContext poemContext(Melati melati) | |
| 312 | throws InvalidArgumentsException { | |
| 313 | 38 | String[] args = melati.getArguments(); |
| 314 | ||
| 315 | 38 | PoemContext pc = new PoemContext(); |
| 316 | 38 | if (args.length > 0) { |
| 317 | 36 | pc.setLogicalDatabase(args[0]); |
| 318 | 36 | setTableTroidMethod(pc, (String[])ArrayUtils.section(args, 1, args.length)); |
| 319 | } | |
| 320 | ||
| 321 | 36 | return pc; |
| 322 | } | |
| 323 | ||
| 324 | protected void setTableTroidMethod(PoemContext pc, String[] args){ | |
| 325 | 54 | if (args.length == 1) { |
| 326 | 6 | pc.setMethod(args[0]); |
| 327 | } | |
| 328 | 54 | if (args.length == 2) { |
| 329 | 6 | pc.setTable(args[0]); |
| 330 | try { | |
| 331 | 6 | pc.setTroid(new Integer (args[1])); |
| 332 | } | |
| 333 | 2 | catch (NumberFormatException e) { |
| 334 | 2 | pc.setMethod(args[1]); |
| 335 | 4 | } |
| 336 | } | |
| 337 | 54 | if (args.length >= 3) { |
| 338 | 36 | pc.setTable(args[0]); |
| 339 | try { | |
| 340 | 36 | pc.setTroid(new Integer (args[1])); |
| 341 | } | |
| 342 | 2 | catch (NumberFormatException e) { |
| 343 | 2 | throw new UnexpectedExceptionException(new InvalidArgumentsException(args, e)); |
| 344 | 34 | } |
| 345 | 34 | pc.setMethod(args[2]); |
| 346 | } | |
| 347 | 52 | } |
| 348 | ||
| 349 | ||
| 350 | /** | |
| 351 | * This is provided for convenience, so you don't have to specify the | |
| 352 | * logical database in the arguments. This is useful when | |
| 353 | * writing applications where you are only accessing a single database. | |
| 354 | * | |
| 355 | * Simply override {@link #poemContext(Melati melati)} thus: | |
| 356 | * | |
| 357 | * <PRE> | |
| 358 | * protected PoemContext poemContext(Melati melati) | |
| 359 | * throws InvalidArgumentsException { | |
| 360 | * return poemContextWithLDB(melati,"<your logical database name>"); | |
| 361 | * } | |
| 362 | * </PRE> | |
| 363 | * | |
| 364 | */ | |
| 365 | protected PoemContext poemContextWithLDB(Melati melati, | |
| 366 | String logicalDatabase) | |
| 367 | throws InvalidArgumentsException { | |
| 368 | 18 | PoemContext pc = new PoemContext(); |
| 369 | 18 | pc.setLogicalDatabase(logicalDatabase); |
| 370 | 18 | setTableTroidMethod(pc, melati.getArguments()); |
| 371 | 18 | return pc; |
| 372 | } | |
| 373 | ||
| 374 | /** | |
| 375 | * Override this method to do your own thing. | |
| 376 | * | |
| 377 | * @param melati a {@link Melati} containing POEM and other configuration data | |
| 378 | */ | |
| 379 | protected abstract void doPoemRequest(Melati melati) throws Exception; | |
| 380 | ||
| 381 | } |