联合主键--xml

需求：  在T_STUDENTS表中 要将ID和NAME联合作为主键：

 

1.将id和name属性定义到一个主键类中：StudentPK 并重写hashCode()和equals()方法同时要继承Serializable接口

 

package com.zchen.hibernate.sxt.domain;

import java.io.Serializable;

public class StudentPK implements Serializable{
	/**
	 * 
	 */
	private static final long serialVersionUID = -7880746333829652369L;
	private int id;
	private String name;
	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;
	}
	/*@Override
	public boolean equals(Object o){
		if(o instanceof StudentPK){
			StudentPK pk = (StudentPK)o;
			if(this.id == pk.getId() && this.name.equals(pk.getName())){
				return true;
			}
		}
		return false;
	}
	@Override
	public int hashCode(){
		return this.name.hashCode();
	}*/
	@Override
	public int hashCode() {
		final int prime = 31;
		int result = 1;
		result = prime * result + id;
		result = prime * result + ((name == null) ? 0 : name.hashCode());
		return result;
	}
	@Override
	public boolean equals(Object obj) {
		if (this == obj)
			return true;
		if (obj == null)
			return false;
		if (getClass() != obj.getClass())
			return false;
		StudentPK other = (StudentPK) obj;
		if (id != other.id)
			return false;
		if (name == null) {
			if (other.name != null)
				return false;
		} else if (!name.equals(other.name))
			return false;
		return true;
	}

}

 

2.定义实体类： Students 将主键类放到里面：

package com.zchen.hibernate.sxt.domain;

public class Students {
	private StudentPK pk;

	public StudentPK getPk() {
		return pk;
	}

	public void setPk(StudentPK pk) {
		this.pk = pk;
	}

	public int getAge() {
		return age;
	}

	public void setAge(int age) {
		this.age = age;
	}

	public String getAddress() {
		return address;
	}

	public void setAddress(String address) {
		this.address = address;
	}

	private int age;

	private String address;

}

 

3.定义Students.hbm.xml配置文件

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC 
	"-//Hibernate/Hibernate Mapping DTD 3.0//EN"
	"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="com.zchen.hibernate.sxt.domain">

    <class name="Students" table="T_STUDENTS">
        <composite-id name="pk" class="com.zchen.hibernate.sxt.domain.StudentPK">
        	<key-property name="id" column="ID"/>
        	<key-property name="name" column="NAME"/>
        </composite-id>
        <property name="age" column="AGE"/>
        <property name="address" column="ADDRESS"/>
    </class>

</hibernate-mapping>

 

 

4.定义配置文件：Hibernate.cfg.xml  略

<?xml version="1.0"?>
<!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
                                         "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
	<session-factory>
		<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.url">jdbc:mysql:///db_czbk_hibernate</property>
		<property name="connection.username">root</property>
		<property name="connection.password">1234</property>
		<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
		<property name="hbm2ddl.auto">create</property>
		<property name="current_session_context_class">thread</property>
		<property name="cache.provider_class">org.hibernate.cache.NoCacheProvider</property>
		<property name="show_sql">true</property>
		 <mapping resource="com/zchen/hibernate/sxt/domain/Students.hbm.xml" />
	</session-factory>
</hibernate-configuration>

 

 5.测试用例:

package com.zchen.hibernate.sxt.test;

import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
import org.junit.AfterClass;
import org.junit.BeforeClass;
import org.junit.Test;

import com.zchen.hibernate.sxt.domain.StudentPK;
import com.zchen.hibernate.sxt.domain.Students;


public class StudentsTest {
	
	private static SessionFactory sf = null;
	
	@BeforeClass
	public static void beforeClass(){
		try {
			sf = new AnnotationConfiguration().configure().buildSessionFactory();
		} catch (HibernateException e) {
			e.printStackTrace();
		}
	}
	
	@Test
	public void addStduentTest(){
		StudentPK pk = new StudentPK();
		pk.setId(1);
		pk.setName("zchen");
		
		Students s = new Students();
		s.setAge(24);
		s.setAddress("北京");
		s.setPk(pk);

		Session session = sf.getCurrentSession();
		session.beginTransaction();
		
		session.save(s);
		
		session.getTransaction().commit();
	}
	
	@AfterClass
	public static void afterClass(){
		if(sf != null){
			try {
				sf.close();
			} catch (HibernateException e) {
				e.printStackTrace();
			}
		}
	}


}

 

 

输出语句：

11:32:09,818  INFO SchemaExport:226 - Running hbm2ddl schema export
11:32:09,821 DEBUG SchemaExport:242 - import file not found: /import.sql
11:32:09,821  INFO SchemaExport:251 - exporting generated schema to database
11:32:09,822 DEBUG SchemaExport:377 - drop table if exists T_STUDENTS
11:32:09,879 DEBUG SchemaExport:377 - create table T_STUDENTS (ID integer not null, NAME varchar(255) not null, AGE integer, ADDRESS varchar(255), primary key (ID, NAME))
11:32:09,953  INFO SchemaExport:268 - schema export complete
Hibernate: insert into T_STUDENTS (AGE, ADDRESS, ID, NAME) values (?, ?, ?, ?)