Known Pitfalls (FAQ)
- -Annotated classes in dependencies are not found.
- -- hibernate-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. -
-hibernate-maven-plugin always needs a database-connection
- -- The default-configuration executes the created SQL. - Therefore, it needs a valid database-connection and fails, if none is - available. - If you do not need the generated SQL to be executed automatically, - you can set the property hibernate.schema.execute to - false. - This can be achieved with the command-line parameter - -Dhibernate.schema.execute=false or with the following - configuration: -
- --<configuration> - <execute>false</execute> -</configuration>
- But even when no database is to be created, hibernate always needs to know - the dialect. Hence, the plugin will still fail, if this parameter is also - 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 hibernate-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.H2Dialect
-[INFO] hibernate.connection.url = jdbc:h2:file:./db
-[INFO] hibernate.hbm2dll.create_namespaces = false
-[INFO] hibernate.connection.driver_class = org.h2.Driver
-[INFO] hibernate.format_sql = true
-[INFO] HHH000412: Hibernate Core {5.0.2.Final}
-[INFO] HHH000206: hibernate.properties not found
-[INFO] HHH000021: Bytecode provider name : javassist
-[INFO] Adding /home/kai/project/target/classes to the list of roots to scan...
-[INFO] Adding dependencies from scope compile to the list of roots to scan
-[INFO] Adding dependencies from scope org.hibernate:hibernate-core:jar:4.3.0.Final to the list of roots to scan
-[INFO] Adding annotated resource: de.juplo.tests.SimplestMavenHib4Test
-[INFO] ------------------------------------------------------------------------
-[INFO] BUILD FAILURE
-[INFO] ------------------------------------------------------------------------
-[INFO] Total time: 1.760s
-[INFO] Finished at: Mon Mar 07 19:06:54 CET 2016
-[INFO] Final Memory: 11M/215M
-[INFO] ------------------------------------------------------------------------
-[ERROR] Failed to execute goal de.juplo:hibernate-maven-plugin:2.1.0: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 -> [Help 1]
-[ERROR]
-[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
-[ERROR] Re-run Maven using the -X switch to enable full debug logging.
-[ERROR]
-[ERROR] For more information about the errors and possible solutions, please read the following articles:
-[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException- 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>hibernate-maven-plugin</artifactId> - <version>2.1.0</version> - <executions> - <execution> - <goals> - <goal>drop</goal> - <goal>create</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 hibernate was skipped because nothing has changed
- -- If hibernate-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 hibernate-maven-plugin has - skipped its excecution. -
- -- A quick fix to this problem is, to force - hibernate-maven-plugin to generate and execute the SQL 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, hibernate-maven-plugin signals a skipped - excecution by setting the maven property ${hibernate.schema.skipped} to - true. - You can configure other plugins to react on this signal. - For example, the dbunit-plugin can be configured to skip its excecution, if - hibernate-maven-plugin was skipped like this: -
- -
-<plugin>
- <groupId>org.codehaus.mojo</groupId>
- <artifactId>dbunit-maven-plugin</artifactId>
- <configuration>
- <skip>${hibernate.schema.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 hibernate-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 hibernate:create -Dhibernate.schema.force=true
The hibernate:create goal is not executed, when tests are skipped
- -- The hibernate-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>hibernate-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.schema.scan.dependencies=none to maven - or set scanDependencies to none in the configuration - of the plugin like this: -
- --<plugin> - <groupId>de.juplo</groupId> - <artifactId>hibernate-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 are expiriencing a bug, in the scannotation-library, that - was closed in version 1.1.0 of the hibernate-maven-plugin. -
- -- - You should consider to upgrade to the latest version of the plugin. - -
-If two goals are specified, the second one is always skipped
- -- If you specify two goals, for example drop and - create, each goal has to be specified in its own - execution, so that you can specify two different - output-files for the two goals. - Otherwise, both goals will use the same output-file and the goal, that - is run second, will always skip, becaus it will find, that the output - file already exists and conclude, that its work was already done in a - prior run. -
- -- Example configuration for two goals: -
- --<executions> - <execution> - <id>Create Drop-Schema</id> - <phase>test-compile</phase> - <goals> - <goal>drop</goal> - </goals> - <configuration> - <outputFile>db-schema/drop-schema.ddl</outputFile> - </configuration> - </execution> - <execution> - <id>Create Create-Schema</id> - <phase>test-compile</phase> - <goals> - <goal>create</goal> - </goals> - <configuration> - <outputFile>db-schema/create-schema.ddl</outputFile> - </configuration> - </execution> -</executions>