Map based on List collection

1. Using the list collection in an entity class

1  Public class Grade {2     Private int ID; 3     Private String name; 4     Private New Arraylist<student> (0); 5 }

2. mapping files

1 Package= "Cn.siggy.pojo" >2<className= "Grade" >3<id name= "id" >4<generatorclass= "Native" ></generator>5</id>6<property name= "Name"/>7<list name= "Students" cascade= "all" >8<!--key indicates foreign key column name---9<key column= "grade_id" ></key>Ten<!--generate a column at one end to indicate the order if the column name is not indicated by default to IDX One values are maintained by Hibernate A- -<list-index column= "Sort" > -</list-index> the<!--One-to-many the type represented by students in a one-to-many class grade-- -<one-to-manyclass= "Student"/> -</list> -</class>

3. Test code

1 @Test2      Public voidTestsave ()throwshibernateexception, serialexception, sqlexception{3Configuration cfg =NewConfiguration (). Configure ();4Sessionfactory factory = Cfg.buildsessionfactory (NewStandardserviceregistrybuilder ()5 . Applysettings (Cfg.getproperties ()). build ());6Session session =NULL;7Transaction tx =NULL;8         Try{9Session =factory.opensession ();Tentx =session.begintransaction (); OneGrade Grade =NewGrade (); AGrade.setname ("Foundation"); -              -Student stu =NewStudent (); theStu.setname ("Zhang San Crazy"); -Stu.setage (22); -Student STU1 =NewStudent (); -Stu1.setname ("Lao Wang")); +Stu1.setage (23); -Student STU2 =NewStudent (); +Stu2.setname ("Lao Li"); AStu2.setage (23); at             //Associate - grade.getstudents (). Add (stu); - grade.getstudents (). Add (STU1); - grade.getstudents (). Add (STU2); -             //The order in which the data is saved is determined by the configuration of the foreign key. -             //If the foreign key cannot be null, then save one end first in             //If the foreign key can be null, then you can save the - Session.save (grade); to Session.save (stu); + Session.save (STU1); - Session.save (STU2); the              * tx.commit (); $             Panax Notoginseng}Catch(hibernateexception e) { -             if(tx!=NULL) the Tx.rollback (); + e.printstacktrace (); A             Throwe; the}finally{ + hibernateutil.closesession (); -         } $     } $ @Test -      Public voidTestget () { -Session session =NULL; theTransaction tx =NULL; -         Try{WuyiSession =hibernateutil.getsession (); thetx =session.begintransaction (); -             //Fetch Data WuGrade Grade = (Grade) session.get (Grade.class, 1); -System.out.println ("gradename=" +grade.getname ()); AboutSYSTEM.OUT.PRINTLN ("Data for multiple end of grade"); $list<student> list =grade.getstudents (); -              for(Student stu:list) { - System.out.println (Stu.getname ()); -             } A tx.commit (); +}Catch(hibernateexception e) { the             if(tx!=NULL) - Tx.rollback (); $ e.printstacktrace (); the             Throwe; the}finally{ the hibernateutil.closesession (); the         } -}

Map based on List collection