Known Pitfalls (FAQ)
Annotated classes in dependencies are not found.
+ ++ hibernate4-maven-plugin by default scans dependencies in the scope + compile. 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>1.0.5</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 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 + 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 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 To skip or not to skip: that is the question... +
+I do not want my dependencies to be scanned for hibernate annotations
+ ++ If you do not want your dependencies to be scanned for hibernate annotations, + you can pass -Dhibernate.export.scan_dependencies=none to maven + or set scanDependencies to none in the configuration + of the plugin like this: +
+ ++<plugin> + <groupId>de.juplo</groupId> + <artifactId>hibernate4-maven-plugin</artifactId> + ... + <configuration> + <scanDependencies>none</scanDependencies> + </configuration> +</plugin>
No annotated classes found
+ ++ If you are working under Windows and get the error-message + No annotated classes found in directory C:\projects\X Y Z\path-to-project\target\classes, + but you are really sure, that there are annotated classes in that + directory, you should try to rename your folders, so that their names + do not contain any whitespaces. +
+ ++ So fare, I got to bug-reports considering this. + In both cases, removing all whitespaces from the path solved the error. + In both cases, I was not able to reproduce the bug on my development + system, which is running under linux. +
+ ++ + Hence, I assume, this is a sublte bug in the way, the java-version for + Windows is handling paths, that contain whitespaces. + +
+