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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   hibernate-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="hibernate-maven-plugin_always_needs_a_database-connection"></a>hibernate-maven-plugin always needs a database-connection</h2>
  65
  66 <p>
  67   The default-configuration exports the created schema to the configured
  68   database.
  69   Therefore, it needs a valid database-connection and fails, if none is
  70   available.
  71   If you do not need to export the created schema to a database,
  72   you can set the property <tt>hibernate.schema.export</tt> to
  73   <tt>false</tt>.
  74   This can be achieved with the command-line parameter
  75   <tt>-Dhibernate.schema.export=false</tt> or with the following
  76   configuration:
  77   </p>
  78
  79 <div>
  80 <pre class="prettyprint linenums lang-html">
  81 &lt;configuration&gt;
  82   &lt;export&gt;false&lt;/export&gt;
  83 &lt;/configuration&gt;</pre></div>
  84
  85 <p>
  86   But even when no database is to be created, hibernate always needs to know
  87   the dialect. Hence, the plugin will still fail, if this parameter is also
  88   missing!
  89   </p>
  90   </div>
  91 <div class="section">
  92 <h2><a name="Dependency_for_driver-class_XYZ_is_missing"></a>Dependency for driver-class XYZ is missing</h2>
  93
  94 <p>
  95   One regular problem is the scope of the jdbc-driver-dependency.
  96   It is very unlikely, that this dependency is needed at compile-time.
  97   So a tidy maven-developer would usually scope it for <tt>runtime</tt>.
  98   </p>
  99
 100 <p>
 101   But this will break the execution of the <tt>hibernate-maven-plugin</tt>.
 102   Since it will not be able to see the needed dependency, it will fail with
 103   an error-message like:
 104   </p>
 105
 106 <div>
 107 <pre class="prettyprint">
 108 [INFO] Gathered hibernate-configuration (turn on debugging for details):
 109 [INFO]   hibernate.connection.username = sa
 110 [INFO]   hibernate.connection.password =
 111 [INFO]   hibernate.dialect = org.hibernate.dialect.H2Dialect
 112 [INFO]   hibernate.connection.url = jdbc:h2:file:./db
 113 [INFO]   hibernate.hbm2dll.create_namespaces = false
 114 [INFO]   hibernate.connection.driver_class = org.h2.Driver
 115 [INFO]   hibernate.format_sql = true
 116 [INFO] HHH000412: Hibernate Core {5.0.2.Final}
 117 [INFO] HHH000206: hibernate.properties not found
 118 [INFO] HHH000021: Bytecode provider name : javassist
 119 [INFO] Adding /home/kai/project/target/classes to the list of roots to scan...
 120 [INFO] Adding dependencies from scope compile to the list of roots to scan
 121 [INFO] Adding dependencies from scope org.hibernate:hibernate-core:jar:4.3.0.Final to the list of roots to scan
 122 [INFO] Adding annotated resource: de.juplo.tests.SimplestMavenHib4Test
 123 [INFO] ------------------------------------------------------------------------
 124 [INFO] BUILD FAILURE
 125 [INFO] ------------------------------------------------------------------------
 126 [INFO] Total time: 1.760s
 127 [INFO] Finished at: Mon Mar 07 19:06:54 CET 2016
 128 [INFO] Final Memory: 11M/215M
 129 [INFO] ------------------------------------------------------------------------
 130 [ERROR] Failed to execute goal de.juplo:hibernate-maven-plugin:2.0.0:drop (default) on project hibernate4-properties-test: Could not open the JDBC-connection: Unable to load class [org.h2.Driver]: Could not load requested class : org.h2.Driver -&gt; [Help 1]
 131 [ERROR]
 132 [ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
 133 [ERROR] Re-run Maven using the -X switch to enable full debug logging.
 134 [ERROR]
 135 [ERROR] For more information about the errors and possible solutions, please read the following articles:
 136 [ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException</pre></div>
 137
 138 <p>
 139   A quick workaround for this error would be, to delete the runtime-constraint
 140   for the jdbc-driver-dependency.
 141   </p>
 142
 143 <p>
 144   A much cleaner way is, to (additionally) ad the dependency, to the
 145   plugin-definition:
 146   </p>
 147
 148 <div>
 149 <pre class="prettyprint linenums lang-html">
 150 &lt;plugin&gt;
 151   &lt;groupId&gt;de.juplo&lt;/groupId&gt;
 152   &lt;artifactId&gt;hibernate-maven-plugin&lt;/artifactId&gt;
 153   &lt;version&gt;2.0.0&lt;/version&gt;
 154   &lt;executions&gt;
 155     &lt;execution&gt;
 156       &lt;goals&gt;
 157         &lt;goal&gt;drop&lt;/goal&gt;
 158         &lt;goal&gt;create&lt;/goal&gt;
 159       &lt;/goals&gt;
 160     &lt;/execution&gt;
 161   &lt;/executions&gt;
 162   &lt;dependencies&gt;
 163   &lt;dependency&gt;
 164     &lt;groupId&gt;org.hsqldb&lt;/groupId&gt;
 165     &lt;artifactId&gt;hsqldb&lt;/artifactId&gt;
 166     &lt;version&gt;2.2.8&lt;/version&gt;
 167   &lt;/dependency&gt;
 168   &lt;/dependencies&gt;
 169 &lt;/plugin&gt;</pre></div>
 170
 171 <p>
 172   This is also the best way, if you use a different jdbc-driver for
 173   testing, than in production.
 174   Because otherwise, this dependency will unnecessarily bloat the
 175   runtime-dependencies of your project.
 176   </p>
 177   </div>
 178 <div class="section" id="fails">
 179 <h2 id="fails">DBUnit fails after execution of hibernate was skipped because nothing has changed</h2>
 180
 181 <p>
 182   If hibernate-maven-plugin skips its excecution, this may lead to errors in
 183   other plugins.
 184   For example, when importing sample-data in the automatically created database
 185   with the help of the <a class="externalLink" href="http://mojo.codehaus.org/dbunit-maven-plugin/">dbunit-plugin</a>,
 186   the <tt>CLEAN_INSERT</tt>-operation may fail because of foreign-key-constraints,
 187   if the database was not recreated, because the hibernate-maven-plugin has
 188   skipped its excecution.
 189   </p>
 190
 191 <p>
 192   A quick fix to this problem is, to <a href="./force.html">force</a>
 193   hibernate-maven-plugin to export the schema every time it is running.
 194   But to recreate the database on every testrun may noticeable slow down your
 195   development cycle, if you have to wait for slow IO.
 196   </p>
 197
 198 <p>
 199   To circumvent this problem, hibernate-maven-plugin signals a skipped
 200   excecution by setting the  maven property <tt>${hibernate.schema.skipped}</tt> to
 201   <tt>true</tt>.
 202   You can configure other plugins to react on this signal.
 203   For example, the dbunit-plugin can be configured to skip its excecution, if
 204   hibernate-maven-plugin was skipped like this:
 205   </p>
 206
 207 <div>
 208 <pre class="prettyprint linenums lang-html">
 209 &lt;plugin&gt;
 210   &lt;groupId&gt;org.codehaus.mojo&lt;/groupId&gt;
 211   &lt;artifactId&gt;dbunit-maven-plugin&lt;/artifactId&gt;
 212   &lt;configuration&gt;
 213     &lt;skip&gt;${hibernate.schema.skipped}&lt;/skip&gt;
 214   &lt;/configuration&gt;
 215 &lt;/plugin&gt;</pre></div>
 216   </div>
 217 <div class="section">
 218 <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>
 219
 220 <p>
 221   If one manually drops the database or removes the hsqldb-files, it will not
 222   be recreated by the hibernate-maven-plugin, because it cannot detect, that
 223   the database needs to be recreated.
 224   This happens, because the plugin will not recreate the database if neither
 225   the configuration nor the annotated classes have changed, because an
 226   unnecessary drop-create-cycle might take a long time. The plugin will
 227   report that like this:
 228   </p>
 229
 230 <div>
 231 <pre class="prettyprint">
 232 [INFO] No modified annotated classes found and dialect unchanged.
 233 [INFO] Skipping schema generation!</pre></div>
 234
 235 <p>
 236   If one always uses <tt>mvn clean</tt> for cleanup, this will not happen.
 237   Otherwise the recreation must be <a href="./force.html">forced</a>:
 238   </p>
 239
 240 <div>
 241 <pre class="prettyprint">
 242 mvn hibernate:create -Dhibernate.schema.force=true</pre></div>
 243   </div>
 244 <div class="section">
 245 <h2><a name="The_hibernate:create_goal_is_not_executed_when_tests_are_skipped"></a>The hibernate:create goal is not executed, when tests are skipped</h2>
 246
 247 <p>
 248   The hibernate-maven-plugin automatically skips its execution, when
 249   <tt>maven.test.skip</tt> is set to <tt>true</tt>. If you need it to be always
 250   executed, you can configure that explicitly like this:
 251   </p>
 252
 253 <div>
 254 <pre class="prettyprint linenums lang-html">
 255 &lt;plugin&gt;
 256   &lt;groupId&gt;de.juplo&lt;/groupId&gt;
 257   &lt;artifactId&gt;hibernate-maven-plugin&lt;/artifactId&gt;
 258   ...
 259   &lt;configuration&gt;
 260     &lt;skip&gt;false&lt;/skip&gt;
 261   &lt;/configuration&gt;
 262 &lt;/plugin&gt;</pre></div>
 263
 264 <p>
 265   Background-information for this design-decission can be found on the extra
 266   page <a href="./skip.html">To skip or not to skip: that is the question</a>...
 267   </p>
 268   </div>
 269 <div class="section">
 270 <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>
 271
 272 <p>
 273     If you do not want your dependencies to be scanned for hibernate annotations,
 274     you can pass <tt>-Dhibernate.schema.scan.dependencies=none</tt> to maven
 275     or set <tt>scanDependencies</tt> to <tt>none</tt> in the configuration
 276     of the plugin like this:
 277   </p>
 278
 279 <div>
 280 <pre class="prettyprint linenums lang-html">
 281 &lt;plugin&gt;
 282   &lt;groupId&gt;de.juplo&lt;/groupId&gt;
 283   &lt;artifactId&gt;hibernate-maven-plugin&lt;/artifactId&gt;
 284   ...
 285   &lt;configuration&gt;
 286     &lt;scanDependencies&gt;none&lt;/scanDependencies&gt;
 287   &lt;/configuration&gt;
 288 &lt;/plugin&gt;</pre></div>
 289   </div>
 290 <div class="section">
 291 <h2><a name="No_annotated_classes_found"></a>No annotated classes found</h2>
 292
 293 <p>
 294     If you are working under Windows and get the error-message
 295     <tt>No annotated classes found in directory C:\projects\X Y Z\path-to-project\target\classes</tt>,
 296     but you are really sure, that there are annotated classes in that
 297     directory, you are expiriencing a bug, in the scannotation-library, that
 298     was closed in version 1.1.0 of the hibernate-maven-plugin.
 299   </p>
 300
 301 <p>
 302     <b>
 303       You should consider to upgrade to the latest version of the plugin.
 304     </b>
 305   </p>
 306  </div>
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