Hibernate一对多(多对一)双向关联(annotation/xml)

1.annotatiton

实体类

Group.java

package com.test.hiberenate.model;

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

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.OneToMany;
import javax.persistence.Table;

@Entity
@Table(name = "t_group")
public class Group {
	private int id;
	private String name;
	private Set<User> users = new HashSet<User>();

	@Id
	@GeneratedValue
	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;
	}

	@OneToMany(mappedBy="group")
	public Set<User> getUsers() {
		return users;
	}

	public void setUsers(Set<User> users) {
		this.users = users;
	}

}

 

User.java

package com.test.hiberenate.model;

import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;

@Entity
@Table(name = "t_user")
public class User {
	private int id;
	private String name;
	private Group group;

	@Id
	@GeneratedValue
	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;
	}

	@ManyToOne
	@JoinColumn(name="group_id")
	public Group getGroup() {
		return group;
	}

	public void setGroup(Group group) {
		this.group = group;
	}

}

 

2.xml

Group.hbm.xml

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

<hibernate-mapping package="com.test.hiberenate.model">
	<class name="Group" table="t_group">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" />
		<set name="users">
			<key column="group_id"></key>
			<one-to-many class="User"/>
		</set>
	</class>
</hibernate-mapping>

 

User.hbm.xml

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

<hibernate-mapping package="com.test.hiberenate.model">
	<class name="User" table="t_user">
		<id name="id">
			<generator class="native"></generator>
		</id>
		<property name="name" />
		<many-to-one name="group" column="group_id"></many-to-one>
	</class>
</hibernate-mapping>