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  46           <header><h1>Known Pitfalls (FAQ)</h1></header>
  47
  48
  49
  50
  51 <div class="section">
  52 <h2><a name="Annotated_classes_in_dependencies_are_not_found."></a>Annotated classes in dependencies are not found.</h2>
  53
  54 <p>
  55   hibernate4-maven-plugin by default scans dependencies in the scope
  56   <tt>compile</tt>. You can configure it to scan dependencies in other
  57   scopes as well. But it scans only direct dependencies. Transitive
  58   dependencies are not scanned for annotated classes. If some of your
  59   annotated classes are hidden in a transitive dependency, you can simply
  60   add that dependency explicitly.
  61   </p>
  62   </div>
  63 <div class="section">
  64 <h2><a name="hibernate4-maven-plugin_always_needs_a_database-connection"></a>hibernate4-maven-plugin always needs a database-connection</h2>
  65
  66 <p>
  67   The default-configuration uses the EXPORT-target of the SchemaExport-Tool.
  68   If you do not need to create a database with the evaluated schema, you can
  69   use the NONE- or the SCRIPT-target.
  70   This can be achieved with the command-line parameter
  71   <tt>-Dhibernate.export.target=SCRIPT</tt> or with the following configuration:
  72   </p>
  73
  74 <div>
  75 <pre class="prettyprint linenums lang-html">
  76 &lt;configuration&gt;
  77   &lt;target&gt;SCRIPT&lt;/target&gt;
  78 &lt;/configuration&gt;</pre></div>
  79
  80 <p>
  81   But even when no database is to be created, hibernate always needs to know
  82   the dialect. Hence, the plugin will fail if this parameter is missing!
  83   </p>
  84   </div>
  85 <div class="section">
  86 <h2><a name="Dependency_for_driver-class_XYZ_is_missing"></a>Dependency for driver-class XYZ is missing</h2>
  87
  88 <p>
  89   One regular problem is the scope of the jdbc-driver-dependency.
  90   It is very unlikely, that this dependency is needed at compile-time.
  91   So a tidy maven-developer would usually scope it for <tt>runtime</tt>.
  92   </p>
  93
  94 <p>
  95   But this will break the execution of the <tt>hibernate4-maven-plugin</tt>.
  96   Since it will not be able to see the needed dependency, it will fail with
  97   an error-message like:
  98   </p>
  99
 100 <div>
 101 <pre class="prettyprint">
 102 [INFO] Gathered hibernate-configuration (turn on debugging for details):
 103 [INFO]   hibernate.connection.username = sa
 104 [INFO]   hibernate.connection.password =
 105 [INFO]   hibernate.dialect = org.hibernate.dialect.HSQLDialect
 106 [INFO]   hibernate.connection.url = jdbc:hsqldb:/home/kai/mmf/target/mmf;shutdown=true
 107 [INFO]   hibernate.connection.driver_class = org.hsqldb.jdbcDriver
 108 [ERROR] Dependency for driver-class org.hsqldb.jdbcDriver is missing!
 109 [INFO] ------------------------------------------------------------------------
 110 [ERROR] BUILD ERROR
 111 [INFO] ------------------------------------------------------------------------
 112 [INFO] org.hsqldb.jdbcDriver
 113 [INFO] ------------------------------------------------------------------------
 114 [INFO] For more information, run Maven with the -e switch
 115 [INFO] ------------------------------------------------------------------------
 116 [INFO] Total time: 2 seconds
 117 [INFO] Finished at: Thu Nov 29 11:31:14 CET 2012
 118 [INFO] Final Memory: 32M/342M
 119 [INFO] ------------------------------------------------------------------------</pre></div>
 120
 121 <p>
 122   A quick workaround for this error would be, to delete the runtime-constraint
 123   for the jdbc-driver-dependency.
 124   </p>
 125
 126 <p>
 127   A much cleaner way is, to (additionally) ad the dependency, to the
 128   plugin-definition:
 129   </p>
 130
 131 <div>
 132 <pre class="prettyprint linenums lang-html">
 133 &lt;plugin&gt;
 134   &lt;groupId&gt;de.juplo&lt;/groupId&gt;
 135   &lt;artifactId&gt;hibernate4-maven-plugin&lt;/artifactId&gt;
 136   &lt;version&gt;1.1.0&lt;/version&gt;
 137   &lt;executions&gt;
 138     &lt;execution&gt;
 139       &lt;goals&gt;
 140         &lt;goal&gt;export&lt;/goal&gt;
 141       &lt;/goals&gt;
 142     &lt;/execution&gt;
 143   &lt;/executions&gt;
 144   &lt;dependencies&gt;
 145   &lt;dependency&gt;
 146     &lt;groupId&gt;org.hsqldb&lt;/groupId&gt;
 147     &lt;artifactId&gt;hsqldb&lt;/artifactId&gt;
 148     &lt;version&gt;2.2.8&lt;/version&gt;
 149   &lt;/dependency&gt;
 150   &lt;/dependencies&gt;
 151 &lt;/plugin&gt;</pre></div>
 152
 153 <p>
 154   This is also the best way, if you use a different jdbc-driver for
 155   testing, than in production.
 156   Because otherwise, this dependency will unnecessarily bloat the
 157   runtime-dependencies of your project.
 158   </p>
 159   </div>
 160 <div class="section" id="fails">
 161 <h2 id="fails">DBUnit fails after execution of hibernate4 was skipped because nothing has changed</h2>
 162
 163 <p>
 164   If hibernate4-maven-plugin skips its excecution, this may lead to errors in
 165   other plugins.
 166   For example, when importing sample-data in the automatically created database
 167   with the help of the <a class="externalLink" href="http://mojo.codehaus.org/dbunit-maven-plugin/">dbunit-plugin</a>,
 168   the <tt>CLEAN_INSERT</tt>-operation may fail because of foreign-key-constraints,
 169   if the database was not recreated, because the hibernate4-maven-plugin has
 170   skipped its excecution.
 171   </p>
 172
 173 <p>
 174   A quick fix to this problem is, to <a href="./force.html">force</a>
 175   hibernate4-maven-plugin to export the schema every time it is running.
 176   But to recreate the database on every testrun may noticeable slow down your
 177   development cycle, if you have to wait for slow IO.
 178   </p>
 179
 180 <p>
 181   To circumvent this problem, hibernate4-maven-plugin signals a skipped
 182   excecution by setting the  maven property <tt>$\{hibernate.export.skipped\}</tt> to
 183   <tt>true</tt>.
 184   You can configure other plugins to react on this signal.
 185   For example, the dbunit-plugin can be configured to skip its excecution, if
 186   hibernate4-maven-plugin was skipped like this:
 187   </p>
 188
 189 <div>
 190 <pre class="prettyprint linenums lang-html">
 191 &lt;plugin&gt;
 192   &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
 193   &lt;artifactId&gt;dbunit-maven-plugin&lt;/artifactId&gt;
 194   &lt;configuration&gt;
 195     &lt;skip&gt;${hibernate.export.skipped}&lt;/skip&gt;
 196   &lt;/configuration&gt;
 197 &lt;/plugin&gt;</pre></div>
 198   </div>
 199 <div class="section">
 200 <h2><a name="The_database_will_not_be_recreated_after_a_manual_dropclean"></a>The database will not be recreated after a manual drop/clean</h2>
 201
 202 <p>
 203   If one manually drops the database or removes the hsqldb-files, it will not
 204   be recreated by the hibernate4-maven-plugin, because it cannot detect, that
 205   the database needs to be recreated.
 206   This happens, because the plugin will not recreate the database if neither
 207   the configuration nor the annotated classes have changed, because an
 208   unnecessary drop-create-cycle might take a long time. The plugin will
 209   report that like this:
 210   </p>
 211
 212 <div>
 213 <pre class="prettyprint">
 214 [INFO] No modified annotated classes found and dialect unchanged.
 215 [INFO] Skipping schema generation!</pre></div>
 216
 217 <p>
 218   If one always uses <tt>mvn clean</tt> for cleanup, this will not happen.
 219   Otherwise the recreation must be <a href="./force.html">forced</a>:
 220   </p>
 221
 222 <div>
 223 <pre class="prettyprint">
 224 mvn hibernate4:export -Dhibernate.export.force=true</pre></div>
 225   </div>
 226 <div class="section">
 227 <h2><a name="The_hibernate4:export_goal_is_not_executed_when_tests_are_skipped"></a>The hibernate4:export goal is not executed, when tests are skipped</h2>
 228
 229 <p>
 230   The hibernate4-maven-plugin automatically skips its execution, when
 231   <tt>maven.test.skip</tt> is set to <tt>true</tt>. If you need it to be always
 232   executed, you can configure that explicitly like this:
 233   </p>
 234
 235 <div>
 236 <pre class="prettyprint linenums lang-html">
 237 &lt;plugin&gt;
 238   &lt;groupId&gt;de.juplo&lt;/groupId&gt;
 239   &lt;artifactId&gt;hibernate4-maven-plugin&lt;/artifactId&gt;
 240   ...
 241   &lt;configuration&gt;
 242     &lt;skip&gt;false&lt;/skip&gt;
 243   &lt;/configuration&gt;
 244 &lt;/plugin&gt;</pre></div>
 245
 246 <p>
 247   Background-information for this design-decission can be found on the extra
 248   page <a href="./skip.html">To skip or not to skip: that is the question</a>...
 249   </p>
 250   </div>
 251 <div class="section">
 252 <h2><a name="I_do_not_want_my_dependencies_to_be_scanned_for_hibernate_annotations"></a>I do not want my dependencies to be scanned for hibernate annotations</h2>
 253
 254 <p>
 255     If you do not want your dependencies to be scanned for hibernate annotations,
 256     you can pass <tt>-Dhibernate.export.scan_dependencies=none</tt> to maven
 257     or set <tt>scanDependencies</tt> to <tt>none</tt> in the configuration
 258     of the plugin like this:
 259   </p>
 260
 261 <div>
 262 <pre class="prettyprint linenums lang-html">
 263 &lt;plugin&gt;
 264   &lt;groupId&gt;de.juplo&lt;/groupId&gt;
 265   &lt;artifactId&gt;hibernate4-maven-plugin&lt;/artifactId&gt;
 266   ...
 267   &lt;configuration&gt;
 268     &lt;scanDependencies&gt;none&lt;/scanDependencies&gt;
 269   &lt;/configuration&gt;
 270 &lt;/plugin&gt;</pre></div>
 271   </div>
 272 <div class="section">
 273 <h2><a name="No_annotated_classes_found"></a>No annotated classes found</h2>
 274
 275 <p>
 276     If you are working under Windows and get the error-message
 277     <tt>No annotated classes found in directory C:\projects\X Y Z\path-to-project\target\classes</tt>,
 278     but you are really sure, that there are annotated classes in that
 279     directory, you are expiriencing a bug, in the scannotation-library, that
 280     was closed in version 1.1.0 of the hibernate-maven-plugin.
 281   </p>
 282
 283 <p>
 284     <b>
 285       You should consider to upgrade to that version of the plugin.
 286     </b>
 287   </p>
 288  </div>
 289
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