Set ing of Hibernate and hibernate ing

Set ing of Hibernate and hibernate ing
List ing

If the persistence class has a List object, you can map the list object by using the <List> element or annotation in the ing file.

For example, one question has multiple answers:

 

1) create a persistence class

package list;import java.util.List;public class Question {private int id;private String qname;private List<String> answers;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getQname() {return qname;}public void setQname(String qname) {this.qname = qname;}public List<String> getAnswers() {return answers;}public void setAnswers(List<String> answers) {this.answers = answers;}}

2) create a ing File

<?xml version='1.0' encoding='UTF-8'?>  <!DOCTYPE hibernate-mapping PUBLIC   "-//Hibernate/Hibernate Mapping DTD 3.0//EN"   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">   
3) add
 <!-- List of XML mapping files -->   <mapping resource="list/Question.hbm.xml"/>
4) test
package list;import java.util.ArrayList;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;public class Test {public static void main(String[] args) {Configuration cfg = new Configuration();cfg.configure("hibernate.cfg.xml");SessionFactory factory = cfg.buildSessionFactory();Session session = factory.openSession();session.beginTransaction();ArrayList<String> list1 = new ArrayList<String>();list1.add("answer1");list1.add("answer2");Question question1  = new Question();question1.setQname("question1");question1.setAnswers(list1);session.save(question1);session.getTransaction().commit();session.close();//factory.close();}}

Two-List one-to-multiple ing
One question has multiple answers, and each answer has its own information. You need to use one-to-many associations for ing.
1) create a persistence class
package list;import java.util.List;public class Question {private int id;private String qname;private List<Answer> answers;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getQname() {return qname;}public void setQname(String qname) {this.qname = qname;}public List<Answer> getAnswers() {return answers;}public void setAnswers(List<Answer> answers) {this.answers = answers;}}
package list;public class Answer {private int id;private String answername;private String postedBy;public int getId() {return id;}public void setId(int id) {this.id = id;}public String getAnswername() {return answername;}public void setAnswername(String answername) {this.answername = answername;}public String getPostedBy() {return postedBy;}public void setPostedBy(String postedBy) {this.postedBy = postedBy;}}
2) configuration file
<?xml version='1.0' encoding='UTF-8'?>  <!DOCTYPE hibernate-mapping PUBLIC   "-//Hibernate/Hibernate Mapping DTD 3.0//EN"   "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">   
3) Add the configuration in hibernate. cfg. xml.
 <!-- List of XML mapping files -->   <mapping resource="list/Question.hbm.xml"/>
4) test
package list;import java.util.ArrayList;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.cfg.Configuration;public class Test {public static void main(String[] args) {Configuration cfg = new Configuration();cfg.configure("hibernate.cfg.xml");SessionFactory factory = cfg.buildSessionFactory();Session session = factory.openSession();session.beginTransaction();Answer ans1 = new Answer();ans1.setAnswername("ans1");ans1.setPostedBy("post1");Answer ans2 = new Answer();ans2.setAnswername("ans2");ans2.setPostedBy("post2");Answer ans3 = new Answer();ans3.setAnswername("ans3");ans3.setPostedBy("post3");ArrayList<Answer> list1 = new ArrayList<Answer>();list1.add(ans1);list1.add(ans2);list1.add(ans3);Question question1  = new Question();question1.setQname("question1");question1.setAnswers(list1);session.save(question1);session.getTransaction().commit();session.close();//factory.close();}}