EJB manytomany

@Entity @Table(name="teacher")
public class Teacher {
private Integer id;
private String name;
private Set<Student> students = new HashSet<Student>();
@ManyToMany
@JoinTable(name="mid",inverseJoinColumns=@JoinColumn(name="studentid"),joinColumns=@JoinColumn(name="teacherid"))
public Set<Student> getStudents() {
   return students;
}

public void setStudents(Set<Student> students) {
   this.students = students;
}
@Id @GeneratedValue
public Integer getId() {
   return id;
}

public void setId(Integer id) {
   this.id = id;
}

public String getName() {
   return name;
}

public void setName(String name) {
   this.name = name;
}

}

@Entity @Table(name="student")
public class Student {
private Integer id;
private String name;
private Set<Teacher> teachers = new HashSet<Teacher>();
@Id @GeneratedValue
public Integer getId() {
   return id;
}
public void setId(Integer id) {
   this.id = id;
}

public String getName() {
   return name;
}
public void setName(String name) {
   this.name = name;
}
@ManyToMany(mappedBy="students")
public Set<Teacher> getTeachers() {
   return teachers;
}
public void setTeachers(Set<Teacher> teachers) {
   this.teachers = teachers;
}


}