hb : Many to Many Xml Mapping

Course.java
============

package myhb;

import java.util.Set;

public class Course {

private int courseId;
private String courseName;
private int duration;
private Set students;

public int getCourseId() {
return courseId;
}

public void setCourseId(int courseId) {
this.courseId = courseId;
}

public String getCourseName() {
return courseName;
}

public void setCourseName(String courseName) {
this.courseName = courseName;
}

public int getDuration() {
return duration;
}

public void setDuration(int duration) {
this.duration = duration;
}

public Set getStudents() {
return students;
}

public void setStudents(Set students) {
this.students = students;
}

}

Student.java
=============

package myhb;

import java.util.Set;

public class Student {

private int studentId;
private String studentName;
private int marks;

private Set courses;

public int getStudentId() {
return studentId;
}

public void setStudentId(int studentId) {
this.studentId = studentId;
}

public String getStudentName() {
return studentName;
}

public void setStudentName(String studentName) {
this.studentName = studentName;
}

public int getMarks() {
return marks;
}

public void setMarks(int marks) {
this.marks = marks;
}

public Set getCourses() {
return courses;
}

public void setCourses(Set courses) {
this.courses = courses;
}


}
course.hbm.xml
==============

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> 
 <class name="myhb.Course" table="courses">  
        
     <id name="courseId" column="courseid" ></id>

     <property name="courseName" column="coursename" length="20" ></property>
     <property name="duration" ></property>

  <set name="students" inverse="false" cascade="all" table="students_courses">
     
      <key column="course_id" ></key>
      
      <many-to-many class="myhb.Student" column="student_id "></many-to-many>

  </set>

  </class> 
  
  student.hbm.xml
  ================
  
</hibernate-mapping>

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC
"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">

<hibernate-mapping> 
   <class name="myhb.Student" table="student">  
        
       <id name="studentId" column="studentid" ></id>

    <property name="studentName" column="studentname" length="20" ></property>
    <property name="marks" ></property>

  <set name="courses" cascade="all" table="students_courses">
     
      <key column="student_id "></key>
      <many-to-many class="myhb.Course" column="course_id" ></many-to-many>

  </set>

  </class>   
  
</hibernate-mapping>

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
  <session-factory>
    <property name="hibernate.dialect">org.hibernate.dialect.DerbyDialect</property>
    <property name="hibernate.connection.driver_class">org.apache.derby.jdbc.ClientDriver</property>
    <property name="hibernate.connection.url">jdbc:derby://localhost:1527/technology</property>
    <property name="hibernate.connection.username">app</property>
    <property name="hibernate.connection.password">app</property>
    <property name="show_sql">true</property>
    <property name="hbm2ddl.auto">create</property>
    <mapping resource="student.hbm.xml"/>
    <mapping resource="course.hbm.xml"/>
  </session-factory>
</hibernate-configuration>

OurLogic.java
=============

package myhb;

import java.util.HashSet;
import java.util.Set;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;

public class OurLogic {

public static void main(String args[])
{

Configuration cfg = new Configuration().configure("hibernate.cfg.xml"); 
                
SessionFactory factory = cfg.buildSessionFactory();
Session session = factory.openSession();

Student s1=new Student();
s1.setStudentId(100);
s1.setStudentName("James");
s1.setMarks(98);

Student s2=new Student();
s2.setStudentId(101);
s2.setStudentName("Lee");
s2.setMarks(99);
                
Course c1=new Course();
c1.setCourseId(500);
c1.setCourseName("Hibernate");
c1.setDuration(7);

Course c2=new Course();
c2.setCourseId(501);
c2.setCourseName("Java");
c2.setDuration(30);


Set s =new HashSet();
     s.add(c1);
     s.add(c2);

s1.setCourses(s);
s2.setCourses(s);


   Transaction tx = session.beginTransaction();
               
                     session.save(s1);
                     session.save(s2);
                    
   tx.commit();
   
   
   session.close();
   System.out.println("Many To Many Bi-Directional is Done..!!");
   factory.close();
}
}