我回复我自己的问题，也许这个答案对别人有用。 b $ b

到现在为止，我只找到一种方法来实现给定的模型 - 通过 Hibernate XML映射文件：

 < hibernate-mapping package =mappingtest> 
< class name =Activity> 
< id name =id> 
< generator class =native/> 
< / id> 
< set name =intervals> 
< key column =activity_idnot-null =true/> 
< element type =org.joda.time.contrib.hibernate.PersistentInterval> 
< column name =startDate/> 
< column name =endDate/> 
< / element> 
< / set> 
< / class> 
< / hibernate-mapping> 
 

和域类实现：

  class Activity {
 Long id 
 Set intervals = [] 

 static constraints = {
} 
} 
 

我还必须将domain class从grails-app / domain移动到src / groovy目录，否则应用程序运行失败使用（grails-1.3.5）：

...

org.hibernate.DuplicateMappingException：
复制类/实体映射
mappingtest.Activity

...

上述第二个问题实现我发现当我通过以下方式打开脚手架（用于测试目的）时：

  class ActivityController {
 static scaffold = true 
 ... 
} 
 

显示创建的活动失败错误：

异常消息：没有这样的属性：
id fo r类：org.joda.time.Interval
可能的解决方案：end引起：
在
行[38]上评估表达式[i.id]时出错：没有这样的属性：id为
class：org.joda.time.Interval可能的
解决方案：end

但手动实现从DB和它的显示工作。

编辑：另外我找到了脚手架和DuplicateMappingException问题的解决方案。它们是由Activity.hbm.xml的无效位置导致的 - 程序包目录结构丢失。正确的位置是grails-app / conf / hibernate / mappingtest / Activity.hbm.xml。

I am wondering if is possible to implement following domain model.

Let's have a domain class which contains set of intervals (joda time). I can use org.joda.time.contrib.hibernate.PersistentInterval hibernate user type for mapping of Interval to database table (by similar way as in http://www.grails.org/JodaTime+Plugin). However I cannot figure out how to implement mapping if I have set of intervals, not only one interval.

Example:

class Activity {  
   ...    
   Set intervals = []  
   ...  
   static hasMany = [    
       intervals: org.joda.time.Interval  
   ]  

   // This is incorrect implementation, I have set of intervals  
   // and this would be correct if I had only one interval  
   // How to implement mapping in this case?  
   static mapping = {  
       intervals type: PersistentInterval, {  
           column name: "start"  
           column name: "end"  
       }  
   }  

}

Implementation above fails with following error:

2010-10-23 18:30:25,483 [main] ERROR context.GrailsContextLoader - Error executing bootstraps: Error creating bean with name 'messageSource': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.MappingException: Foreign key (FK4FDC5B1E5107CA0:activity_intervals [start,end])) must have same number of columns as the referenced primary key (activity [id]) org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'messageSource': Initialization of bean failed; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'transactionManager': Cannot resolve reference to bean 'sessionFactory' while setting bean property 'sessionFactory'; nested exception is org.springframework.beans.factory.BeanCreationException: Error creating bean with name 'sessionFactory': Invocation of init method failed; nested exception is org.hibernate.MappingException: Foreign key (FK4FDC5B1E5107CA0:activity_intervals [start,end])) must have same number of columns as the referenced primary key (activity [id]) at org.grails.tomcat.TomcatServer.start(TomcatServer.groovy:212)

I thought that work-around of this issue is to extract Interval to separate domain class extending Interval and specify mapping within it. However, Interval is final class so extending is not possible.

Thanks for your advices.

I am replying my own question, maybe this answer will be useful for someone.

Until now I have found only one way how to implement given model - by Hibernate XML mapping files:

<hibernate-mapping package="mappingtest">  
    <class name="Activity">  
        <id name="id">  
            <generator class="native"/>  
        </id>  
        <set name="intervals">  
            <key column="activity_id" not-null="true"/>  
            <element type="org.joda.time.contrib.hibernate.PersistentInterval">  
                <column name="startDate"/>  
                <column name="endDate"/>  
            </element>  
        </set>  
    </class>  
</hibernate-mapping>  

and domain class implementation:

class Activity {    
    Long id    
    Set intervals = []

    static constraints = {
    }
}

I also had to move domain class from grails-app/domain to src/groovy directory, otherwise application running failed with (grails-1.3.5):

...
org.hibernate.DuplicateMappingException: Duplicate class/entity mapping mappingtest.Activity
...

Second problem with above implementation I have discovered is that when I turned on scaffolding (for testing purpose) by:

class ActivityController {
    static scaffold = true
    ...
}

showing of created activity failed with error:

Exception Message: No such property: id for class: org.joda.time.Interval Possible solutions: end Caused by: Error evaluating expression [i.id] on line [38]: No such property: id for class: org.joda.time.Interval Possible solutions: end

but manual implementation of getting activities from DB and its showing worked.

Edit: additionally I found solution of scaffolding and DuplicateMappingException issues. They were caused by invalid location of Activity.hbm.xml - package directory structure was missing. Correct location is grails-app/conf/hibernate/mappingtest/Activity.hbm.xml.