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Java > Open Source Codes > example > cmp > ejbql > CourseHome


1 package example.cmp.ejbql;
2
3 import javax.ejb.CreateException;
4 import javax.ejb.EJBLocalHome;
5 import javax.ejb.EJBHome;
6 import javax.ejb.FinderException;
7
8 import java.util.Collection;
9
10 /**
11  * Home interface for the Course bean.
12  * The Home Interface enables you to create new entities and to obtain
13  * references to existing ones.
14  *
15  * <p>The CourseHome example provides two finder methods: the standard
16  * findByPrimaryKey and a findByHouse method. Find methods for a local
17  * home always return the local interface or a collection of
18  * the local interface.
19  *
20  * <p/>All find methods except findByPrimaryKey need an EJB-QL query in
21  * the deployement descriptor.
22  */
23 public interface CourseHome extends EJBLocalHome {
24   /**
25    * This is an example of a finder method that returns a single entity if
26    * successful, and throws an <code>ObjectNotFoundException</code> if it
27    * was unsuccessful.
28    * Every entity EJB needs to define this finder method that looks for an
29    * entity based on the primary key.
30    */
31   Course findByPrimaryKey(String primaryKey)
32     throws FinderException;
33
34   /**
35    * Finds all the courses for the students living in a house. The example
36    * methods shows how a query can use the IN(...) expression to select
37    * a collection of entities.
38    *
39    * <code><pre>
40    * SELECT DISTINCT OBJECT(course)
41    * FROM ejbql_student student, IN(student.courseList) course
42    * WHERE student.house.name=?1
43    * </pre></code>
44    *
45    * @param house the name of the student's house.
46    *
47    * @return the matching collection of courses.
48    */
49   Collection findByHouse(String house)
50     throws FinderException;
51 }
52
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