Grails null service

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Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back Featured on Meta. Command Line Usage. Constraints Usage. Controllers Usage. Database Mapping Usage. Domain Classes Usage. Plug-ins Usage. If no package is specified with the create-service script, Grails automatically uses the grails.

Declarative Transactions Services are typically involved with coordinating logic between domain classes , and hence often involved with persistence that spans large operations. Version Grails 3. Checked exceptions did not roll back transactions before GORM 6. Only a method which threw a runtime exception i. Warning: dependency injection is the only way that declarative transactions work.

You will not get a transactional service if you use the new operator such as new BookService. The Transactional annotation vs the transactional property In versions of Grails prior to Grails 3. In addition, prior to Grails 3. Custom Transaction Configuration Grails also provides Transactional and NotTransactional annotations for cases where you need more fine-grained control over transactions at a per-method level or need to specify an alternative propagation level.

Transaction status An instance of TransactionStatus is available by default in Grails transactional service methods. ReadOnly import grails. Transactional import groovy.

Understanding Transactions and the Hibernate Session When using transactions there are important considerations you must take into account with regards to how the underlying persistence session is handled by Hibernate. If you were to save two authors using consecutive transactions as follows:. This is the optimal solution as it requires fewer queries than the following suggested solutions. Another solution is to redirect the request after a transaction rollback:.

Validation Errors and Rollback A common use case is to rollback a transaction if there are validation errors. If your service is flash , flow or conversation scoped it must implement java.

Serializable and can only be used in the context of a Web Flow. Lazy initialization You can also configure whether the service is lazily initialized. Dependency Injection Basics A key aspect of Grails services is the ability to use Spring Framework 's dependency injection features. NOTE: Normally the property name is generated by lower casing the first letter of the type.

For example, an instance of the BookService class would map to a property named bookService. See section 8. Only the top level object is subjected to injection as traversing all nested objects to perform injection would be a performance issue. Be careful when injecting the non-default datasources.

For example, using this config:. You can inject the primary dataSource like you would expect:. Dependency Injection and Services You can inject services in other services with the same technique.