【7.5.1】基于主键的双向多对多的关联映射
1.角色Role 和功能 Function
2.类Role 和Function类
public class Role { private int id; private String name; private Set<Function> functions = new HashSet<Function>(0); //get…set } public class Function { private int id; private String name; private String code; private String url; private Set<Role> roles = new HashSet<Role>(0); public Function() { // TODO Auto-generated constructor stub } public Function(String name, String code, String url) { super(); this.name = name; this.code = code; this.url = url; } //get…set }
3.映射文件
Role.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="cn.siggy.pojo"> <class name="Function"> <id name="id"> <generator class="native"/> </id> <property name="name"/> <property name="code"/> <property name="url"/> <set name="roles" table="role_func" inverse="true"> <key column="fid"/> <many-to-many column="rid" class="Role"/> </set> </class> </hibernate-mapping>
function.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="cn.siggy.pojo"> <class name="Role"> <id name="id"> <generator class="native"></generator> </id> <property name="name"/> <!-- 多对多 --> <set name="functions" table="role_func" cascade="save-update"> <!-- 表示当前类 映射到关系表中的列--> <key column="rid"/> <!-- 所对应的另一方在关系表中的列 --> <many-to-many column="fid" class="Function"/> </set> </class> </hibernate-mapping>
4.测试代码
package cn.siggy.test; import java.sql.SQLException; import java.util.Iterator; import javax.sql.rowset.serial.SerialException; import org.hibernate.HibernateException; import org.hibernate.Session; import org.hibernate.Transaction; import org.hibernate.cfg.Configuration; import org.hibernate.tool.hbm2ddl.SchemaExport; import org.junit.Test; import cn.siggy.pojo.Function; import cn.siggy.pojo.Role; import cn.siggy.util.HibernateUtil; public class HibernateTest { @Test public void testCreateDB(){ Configuration cfg = new Configuration().configure(); SchemaExport se = new SchemaExport(cfg); //第一个参数 是否生成ddl脚本 第二个参数 是否执行到数据库中 se.create(true, true); } @Test public void testSave() throws HibernateException, SerialException, SQLException{ Session session = null; Transaction tx = null; try{ session = HibernateUtil.getSession(); tx = session.beginTransaction(); Function f1 = new Function("用户管理","user_mag","userAction"); Function f2 = new Function("角色管理","role_mag","roleAction"); Function f3 = new Function("系统管理","sys_mag","sysAction"); Function f4 = new Function("权限管理","prev_mag","prevAction"); Role r1 = new Role(); r1.setName("admin"); r1.getFunctions().add(f1); r1.getFunctions().add(f2); r1.getFunctions().add(f3); r1.getFunctions().add(f4); Role r2 = new Role(); r2.setName("vip"); r2.getFunctions().add(f1); r2.getFunctions().add(f2); session.save(r1); session.save(r2); tx.commit(); }catch (HibernateException e) { if(tx!=null) tx.rollback(); e.printStackTrace(); throw e; }finally{ HibernateUtil.closeSession(); } } }
5.测试结果
1.执行testSave()
控制台信息:
Hibernate: insert into Role (name) values (?) Hibernate: insert into Function (name, code, url) values (?, ?, ?) Hibernate: insert into Function (name, code, url) values (?, ?, ?) Hibernate: insert into Function (name, code, url) values (?, ?, ?) Hibernate: insert into Function (name, code, url) values (?, ?, ?) Hibernate: insert into Role (name) values (?) Hibernate: insert into role_func (rid, fid) values (?, ?) Hibernate: insert into role_func (rid, fid) values (?, ?) Hibernate: insert into role_func (rid, fid) values (?, ?) Hibernate: insert into role_func (rid, fid) values (?, ?) Hibernate: insert into role_func (rid, fid) values (?, ?) Hibernate: insert into role_func (rid, fid) values (?, ?)
数据库表: