package com.bjsxt.hibernate;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinColumns;
import javax.persistence.JoinTable;
import javax.persistence.ManyToMany;
import javax.persistence.ManyToOne;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;
@Entity
@Table(name="t_teacher")
public class User {
	@Id
	@GeneratedValue
	private int id;
	private String name;
	@ManyToMany
	@JoinTable(name="t_teacher_student",joinColumns={@JoinColumn(name="teacher_Id")},inverseJoinColumns={@JoinColumn(name="student_Id")})
	private Set<Group> students = new HashSet<Group>();
	
	public Set<Group> getStudents() {
		return students;
	}
	public void setStudents(Set<Group> students) {
		this.students = students;
	}
	public int getId() {
		return id;
	}
	
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	
	
}
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package com.bjsxt.hibernate;
import java.util.HashSet;
import java.util.Set;
import javax.persistence.Embedded;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.JoinColumns;
import javax.persistence.ManyToMany;
import javax.persistence.OneToMany;
import javax.persistence.OneToOne;
import javax.persistence.PrimaryKeyJoinColumn;
import javax.persistence.Table;
@Entity
@Table(name="t_student")
public class Group {
	@Id
	@GeneratedValue
	private int id;
	private String name;
	@ManyToMany(mappedBy="students")  //与单向的多对多就 只多了 这一个地方
	private Set<User> teachers = new HashSet<User>();
	
	public Set<User> getTeachers() {
		return teachers;
	}
	public void setTeachers(Set<User> teachers) {
		this.teachers = teachers;
	}
	public int getId() {
		return id;
	}
	
//	public Set<User> getUsers() {
//		return users;
//	}
//	public void setUsers(Set<User> users) {
//		this.users = users;
//	}
	public void setId(int id) {
		this.id = id;
	}
	public String getName() {
		return name;
	}
	public void setName(String name) {
		this.name = name;
	}
	
	
}
原文:http://www.cnblogs.com/lize1215/p/7643032.html