Grails:从 src/groovy 类访问域类的最佳方法是什么？

Question

chalice FAQ说这个:

Q: How can I access domain classes from sources in src/groovy?

Sometimes, you are developing some utility classes that live in src/groovy and which you intend >to use from Services and other artifacts. However, as those classes are pre-compiled by Grails, >it is not possible to instantiate them and write things like Book.findByTitle("Groovy in >Action"). But fortunately, there is a workaround since it's possible to do this:

import org.codehaus.groovy.grails.commons.ApplicationHolder

//…

def book = ApplicationHolder.application.getClassForName("library.Book").findByTitle("Groovy in Action")

The application MUST have finished bootstrapping before the dynamic Gorm methods will function correctly.

但是，似乎我可以直接导入域对象并在我的 src/groovy 类中使​​用 GORM 方法而没有任何问题，例如:

Book.findByTitle("Groovy in Action")

由于 ApplicationHolder 已被弃用，这个建议肯定已经过时了，但是还有什么理由避免直接从 src/groovy 使用域类吗？

Answer 1

你是对的，你指的是过时的信息。您可以在 src/groovy 下定义的类中使用域类。 .

唯一的开销是您必须处理 transactions手动。相反，services内grails-app/services默认处理事务。服务在transactional时处理事务标志设置为真(默认为真，不指定任何内容)。

另一方面，当您从 src/groovy 访问域类时您必须使用 withTransaction阻止手动处理交易..

Book.withTransaction{status->
    def book = Book.findByTitle("Groovy in Action")
    book.title = "Grails in Action"
    book.save()

    status.setRollbackOnly() //Rolls back the transaction
}

引用 withTransaction详情。