package com.entity.manytomany;import java.util.List;import javax.persistence.Entity;import javax.persistence.JoinColumn;import javax.persistence.JoinTable;import javax.persistence.ManyToMany;import com.entity.BaseEntity;@Entitypublic class Student extends BaseEntity{	private String name;	@ManyToMany	//学生是不稳定的一方 所以由学生来维护	@JoinTable(name="student_course",				joinColumns=@JoinColumn(name="s_id"),				inverseJoinColumns=@JoinColumn(name="c_id"))	//关联表的表名	//关联当前表的主键	//关联对方表的主键   （）内的name即关联表内的字段名   可以自己自由设计	private List<Course> courses;	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public List<Course> getCourses() {		return courses;	}	public void setCourses(List<Course> courses) {		this.courses = courses;	}		}

package com.entity.manytomany;import java.util.List;import javax.persistence.Entity;import javax.persistence.ManyToMany;import com.entity.BaseEntity;@Entitypublic class Course extends BaseEntity{	private String name;	@ManyToMany(mappedBy ="courses")	//被学生类的courses对象维护	private List<Student> students;	public String getName() {		return name;	}	public void setName(String name) {		this.name = name;	}	public List<Student> getStudents() {		return students;	}	public void setStudents(List<Student> students) {		this.students = students;	}	}

package com;import java.util.ArrayList;import java.util.List;import org.hibernate.Session;import org.hibernate.Transaction;import org.junit.After;import org.junit.Before;import org.junit.Test;import com.entity.manytomany.Course;import com.entity.manytomany.Student;public class TestManyToMany {	private Session s;	private Transaction tran;@Beforepublic void before(){	s=HibernateUtils.getSession();	tran=s.beginTransaction();	}public void manytomany(){	Course c1=new Course();	Course c2=new Course();	Course c3=new Course();	Student stu1=new Student();	Student stu2=new Student();	Student stu3=new Student();	stu1.setName("zhangsan");	stu2.setName("lisi");	stu3.setName("wangwu");	c1.setName("java");	c2.setName("oracle");	c3.setName("html");	//新建对象	List<Course> courses =new ArrayList<Course>();//建立了一个课程集合	List<Course> courses1 =new ArrayList<Course>();	courses1.add(c2);	courses1.add(c3);	courses.add(c1);	courses.add(c2);	courses.add(c3);	//向集合中插入要选的课程	stu1.setCourses(courses);	stu2.setCourses(courses);	stu3.setCourses(courses1);	//建立关联   将课程集合set到学生的课程属性中   即学生选择了集合中所有的课程	s.save(c1);	s.save(c2);	s.save(c3);	s.save(stu1);	s.save(stu2);	s.save(stu3);}	@Testpublic void manytomanyquery(){	Course c=(Course)s.get(Course.class, 1);	for(Student s:c.getStudents()){		System.out.println(c.getName()+"-------选这门课的学生"+s.getName());	}	Course c1=(Course)s.get(Course.class, 2);	for(Student s:c1.getStudents()){		System.out.println(c1.getName()+"-------选这门课的学生"+s.getName());	}	Course c2=(Course)s.get(Course.class, 3);	for(Student s:c2.getStudents()){		System.out.println(c1.getName()+"-------选这门课的学生"+s.getName());	}}@Afterpublic void after(){	tran.commit();	s.close();}}