+++ /dev/null
- ---
- Known Pitfalls
- ---
- Kai Moritz
- ---
-
-Annotated classes in dependencies are not found.
-
- hibernate4-maven-plugin by default scans dependencies in the scope
- <code>compile</code>. You can configure it to scan dependencies in other
- scopes as well. But it scans only direct dependencies. Transitive
- dependencies are not scanned for annotated classes. If some of your
- annotated classes are hidden in a transitive dependency, you can simply
- add that dependency explicitly.
-
-hibernate4-maven-plugin always needs a database-connection
-
- The default-configuration uses the EXPORT-target of the SchemaExport-Tool.
- If you do not need to create a database with the evaluated schema, you can
- use the NONE- or the SCRIPT-target.
- This can be achieved with the command-line parameter
- <<<-Dhibernate.export.target=SCRIPT>>> or with the following configuration:
-
-------------
-<configuration>
- <target>SCRIPT</target>
-</configuration>
-------------
-
- But even when no database is to be created, hibernate always needs to know
- the dialect. Hence, the plugin will fail if this parameter is missing!
-
-Dependency for driver-class XYZ is missing
-
- One regular problem is the scope of the jdbc-driver-dependency.
- It is very unlikely, that this dependency is needed at compile-time.
- So a tidy maven-developer would usually scope it for <<<runtime>>>.
-
- But this will break the execution of the <<<hibernate4-maven-plugin>>>.
- Since it will not be able to see the needed dependency, it will fail with
- an error-message like:
-
----------------
-[INFO] Gathered hibernate-configuration (turn on debugging for details):
-[INFO] hibernate.connection.username = sa
-[INFO] hibernate.connection.password =
-[INFO] hibernate.dialect = org.hibernate.dialect.HSQLDialect
-[INFO] hibernate.connection.url = jdbc:hsqldb:/home/kai/mmf/target/mmf;shutdown=true
-[INFO] hibernate.connection.driver_class = org.hsqldb.jdbcDriver
-[ERROR] Dependency for driver-class org.hsqldb.jdbcDriver is missing!
-[INFO] ------------------------------------------------------------------------
-[ERROR] BUILD ERROR
-[INFO] ------------------------------------------------------------------------
-[INFO] org.hsqldb.jdbcDriver
-[INFO] ------------------------------------------------------------------------
-[INFO] For more information, run Maven with the -e switch
-[INFO] ------------------------------------------------------------------------
-[INFO] Total time: 2 seconds
-[INFO] Finished at: Thu Nov 29 11:31:14 CET 2012
-[INFO] Final Memory: 32M/342M
-[INFO] ------------------------------------------------------------------------
----------------
-
- A quick workaround for this error would be, to delete the runtime-constraint
- for the jdbc-driver-dependency.
-
- A much cleaner way is, to (additionally) ad the dependency, to the
- plugin-definition:
-
----------------
-<plugin>
- <groupId>de.juplo</groupId>
- <artifactId>hibernate4-maven-plugin</artifactId>
- <version>${project.version}</version>
- <executions>
- <execution>
- <goals>
- <goal>export</goal>
- </goals>
- </execution>
- </executions>
- <dependencies>
- <dependency>
- <groupId>org.hsqldb</groupId>
- <artifactId>hsqldb</artifactId>
- <version>2.2.8</version>
- </dependency>
- </dependencies>
-</plugin>
----------------
-
- This is also the best way, if you use a different jdbc-driver for
- testing, than in production.
- Because otherwise, this dependency will unnecessarily bloat the
- runtime-dependencies of your project.
-
-DBUnit {fails} after execution of hibernate4 was skipped because nothing has changed
-
- If hibernate4-maven-plugin skips its excecution, this may lead to errors in
- other plugins.
- For example, when importing sample-data in the automatically created database
- with the help of the {{{http://mojo.codehaus.org/dbunit-maven-plugin/}dbunit-plugin}},
- the <<<CLEAN_INSERT>>>-operation may fail because of foreign-key-constraints,
- if the database was not recreated, because the hibernate4-maven-plugin has
- skipped its excecution.
-
- A quick fix to this problem is, to {{{./force.html}force}}
- hibernate4-maven-plugin to export the schema every time it is running.
- But to recreate the database on every testrun may noticeable slow down your
- development cycle, if you have to wait for slow IO.
-
- To circumvent this problem, hibernate4-maven-plugin signals a skipped
- excecution by setting the maven property <<<${hibernate.export.skipped}>>> to
- <<<true>>>.
- You can configure other plugins to react on this signal.
- For example, the dbunit-plugin can be configured to skip its excecution, if
- hibernate4-maven-plugin was skipped like this:
-
-------------
-<plugin>
- <groupId>org.codehaus.mojo</groupId>
- <artifactId>dbunit-maven-plugin</artifactId>
- <configuration>
- <skip>${hibernate.export.skipped}</skip>
- </configuration>
-</plugin>
-------------
-
-The database will not be recreated after a manual drop/clean
-
- If one manually drops the database or removes the hsqldb-files, it will not
- be recreated by the hibernate4-maven-plugin, because it cannot detect, that
- the database needs to be recreated.
- This happens, because the plugin will not recreate the database if neither
- the configuration nor the annotated classes have changed, because an
- unnecessary drop-create-cycle might take a long time. The plugin will
- report that like this:
-
--------------
-[INFO] No modified annotated classes found and dialect unchanged.
-[INFO] Skipping schema generation!
--------------
-
- If one always uses <<<mvn clean>>> for cleanup, this will not happen.
- Otherwise the recreation must be {{{./force.html}forced}}:
-
--------------
-mvn hibernate4:export -Dhibernate.export.force=true
--------------
-
-The hibernate4:export goal is not executed, when tests are skipped
-
- The hibernate4-maven-plugin automatically skips its execution, when
- <<<maven.test.skip>>> is set to <<<true>>>. If you need it to be always
- executed, you can configure that explicitly like this:
-
-------------
-<plugin>
- <groupId>de.juplo</groupId>
- <artifactId>hibernate4-maven-plugin</artifactId>
- ...
- <configuration>
- <skip>false</skip>
- </configuration>
-</plugin>
-------------
-
- Background-information for this design-decission can be found on the extra
- page {{{./skip.html}To skip or not to skip: that is the question}}...