标签：
ORM(Object/Relationship Mapping):对象/关系映射Myeclipse反向工程
单向一对多案例：
hibernate配置文件，
<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
<session-factory>
<property name="connection.username">root</property>
<property name="connection.password"></property>
<property name="connection.driver_class">
com.mysql.jdbc.Driver
</property>
<property name="connection.url">
<![CDATA[
jdbc:mysql://localhost:3306/hibernate_first?useUnicode=true&characterEncoding=utf8
]]>
</property>
<property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property>
<property name="show_sql">true</property>
<property name="format_sql">true</property>
<property name="hbm2ddl.auto">create</property>
<mapping resource="com/hpu/entity/Grade.hbm.xml"/>
<mapping resource="com/hpu/entity/Student.hbm.xml"/>
</session-factory>
</hibernate-configuration>package com.hpu.entity;
import java.io.Serializable;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Set;
public class Grade implements Serializable{
private int gid;
private String gname;
private String gdesc;
private Set<Student> students = new HashSet<Student>();
public int getGid() {
return gid;
}
public void setGid(int gid) {
this.gid = gid;
}
public String getGname() {
return gname;
}
public void setGname(String gname) {
this.gname = gname;
}
public String getGdesc() {
return gdesc;
}
public void setGdesc(String gdesc) {
this.gdesc = gdesc;
}
public Set<Student> getStudents() {
return students;
}
public void setStudents(Set<Student> students) {
this.students = students;
}
public Grade(int gid, String gname, String gdesc) {
super();
this.gid = gid;
this.gname = gname;
this.gdesc = gdesc;
}
public Grade(String gname, String gdesc) {
super();
this.gname = gname;
this.gdesc = gdesc;
}
@Override
public String toString() {
return "Grade [gid=" + gid + ", gname=" + gname + ", gdesc="
+ gdesc + ", students=" + students + "]";
}
}
实体类2：
package com.hpu.entity;
import java.io.Serializable;
public class Student implements Serializable{
private int gid;
private int sid;
private String sname;
private String sex;
private Grade grade;
public int getGid() {
return gid;
}
public void setGid(int gid) {
this.gid = gid;
}
public String getSname() {
return sname;
}
public void setSname(String sname) {
this.sname = sname;
}
public String getSex() {
return sex;
}
public void setSex(String sex) {
this.sex = sex;
}
public Grade getGrade() {
return grade;
}
public void setGrade(Grade grade) {
this.grade = grade;
}
public int getSid() {
return sid;
}
public void setSid(int sid) {
this.sid = sid;
}
public Student(){
super();
}
public Student(String sname, String sex) {
super();
this.sname = sname;
this.sex = sex;
}
}
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.hpu.entity.Grade" table="grade"> <id name="gid" column="gid" type="java.lang.Integer"> <generator class="increment"></generator> </id> <property name="gname" type="java.lang.String"> <column name="gname" length="20" not-null="true"></column> </property> <property name="gdesc"> <column name="gdesc"></column> </property> <set name="students" table="student"> <key column="gid"></key> <one-to-many class="com.hpu.entity.Student" /> </set> </class> </hibernate-mapping>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.hpu.entity.Student" table="student"> <id name="sid" column="sid" type="java.lang.Integer"> <generator class="increment"></generator> </id> <property name="sname" type="java.lang.String"> <column name="sname" length="20" not-null="true"></column> </property> <property name="sex"><column name="sex"></column> </property> <many-to-one name="grade" class="com.hpu.entity.Grade" column="gid" cascade="save-update,persist"></many-to-one> </class> </hibernate-mapping>
package com.hpu.util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
private static SessionFactory sessionFactory;
private static Session session;
static {
Configuration config = new Configuration().configure();
StandardServiceRegistryBuilder ssrb = new StandardServiceRegistryBuilder()
.applySettings(config.getProperties());
StandardServiceRegistry ssr = ssrb.build();
sessionFactory = config.buildSessionFactory(ssr);
}
// 获取SessionFactory
public static SessionFactory getSessionFactory() {
return sessionFactory;
}
// 获取Session
public static Session getSession() {
session = sessionFactory.openSession();
return session;
}
// 关闭Session
public static void closeSession(Session session) {
if (session != null) {
session.close();
}
}
}
package com.hpu.test;
import org.hibernate.Session;
import org.hibernate.Transaction;
import com.hpu.entity.Grade;
import com.hpu.entity.Student;
import com.hpu.util.HibernateUtil;
public class Test {
public static void main(String[] args) {
add();
// findStudentsByGrade();
// update();
// delete();
}
public static void add(){
Grade g = new Grade("软件1302","软件1301");
Student stu1 = new Student("黄大于","男");
Student stu2 = new Student("小明","女");
Student stu3 = new Student("小红", "女");
g.getStudents().add(stu1);
g.getStudents().add(stu2);
g.getStudents().add(stu3);
Session session = HibernateUtil.getSession();
Transaction tx = session.beginTransaction();
session.save(g);
session.save(stu1);
session.save(stu2);
session.save(stu3);
tx.commit();
HibernateUtil.closeSession(session);
}
public static void findStudentsByGrade(){
Session session = HibernateUtil.getSession();
Grade grade = (Grade) session.get(Grade.class, 1);
System.out.println(grade.toString());
System.out.println(grade.getGname() + "," + grade.getGdesc());
}
public static void update(){
Grade g = new Grade("网络1301","网络1304");
Session session = HibernateUtil.getSession();
Transaction tx = session.beginTransaction();
Student stu = (Student) session.get(Student.class, 1);
session.save(g);
tx.commit();
HibernateUtil.closeSession(session);
}
public static void delete(){
Session session = HibernateUtil.getSession();
Transaction tx = session.beginTransaction();
Student stu = (Student) session.get(Student.class, 2);
session.delete(stu);
tx.commit();
HibernateUtil.closeSession(session);
}
}
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原文地址：http://blog.csdn.net/wojiaohuangyu/article/details/51344278
