初学Hibernate心得/

 1 <?xml version="1.0" encoding="UTF-8"?> 2 <!DOCTYPE hibernate-configuration PUBLIC 3 ????????"-//Hibernate/Hibernate Configuration DTD 3.0//EN" 4 ????????"http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd"> 5 <!--Hibernate的配置信息 --> 6 <hibernate-configuration> 7 ????<!--配置工厂信息，全局信息 --> 8 ????<session-factory> 9 ????????<!--1、设置四本一言 ?-->10 ????????<!--四本一言 四大基本项： 1、驱动类名 2、指明需要连接的url 3、用户名 4、密码 Hibernate支持不同的数据库，但是每种数据库语法可能有区别，可以使用方言,注意版本 -->11 ????????<!--数据库驱动类全称 ?-->12 ????????<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>13 ????????<!--数据库url地址 ?-->14 ????????<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/text?characterEncoding=UTF-8</property>15 ????????<!--用户名 ?-->16 ????????<property name="hibernate.connection.username">root</property>17 ????????<!--密码 ?-->18 ????????<property name="hibernate.connection.password">1111</property>19 ????????<!--方言 -->20 ????????<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>21 ????????<!--2、全局配置信息 ?-->22 ????????<!--执行DDL的类别：23 ????????create:每次都删除新建24 ????????update:存在就修改，不存在就新建 ?-->25 ????????<property name="hibernate.hbm2ddl.auto">update</property>26 ????????<!--是否显示SQL语句 ?-->27 ????????<property name="hibernate.show_sql">true</property>28 ????????<!--是否格式化SQL语句 ?-->29 ????????<property name="hibernate.format_sql">true</property>30 ????????<!-- 启用getCurrentSession，默认未启用 -->31 ????????<property name="hibernate.current_session_context_class">thread</property>32 ????????<!--3、加载配置文件 ?-->33 ????????<mapping resource="com/Student.hbm.xml"></mapping>34 ????????<mapping resource="com/Classes.hbm.xml"></mapping>35 ????????36 ????</session-factory>37 </hibernate-configuration>

 1 package com; 2 ?3 import java.util.HashSet; 4 import java.util.Set; 5 ?6 public class Classes { 7 ????/** 8 ?????* @param cid 9 ?????* @param name10 ?????*/11 ????public Classes() {}12 ????public Classes(int cid, String name) {13 ????????this.cid = cid;14 ????????this.name = name;15 ????}16 ????private int cid; //标示符属性17 ????private String name; ?//一般属性18 ????private String description;19 ????private Set<Student> student = new HashSet<Student>();20 ????public Set<Student> getStudent() {21 ????????return student;22 ????}23 ????public void setStudent(Set<Student> student) {24 ????????this.student = student;25 ????}26 27 ????public int getCid() {28 ????????return cid;29 ????}30 ????public void setCid(int cid) {31 ????????this.cid = cid;32 ????}33 ????public String getName() {34 ????????return name;35 ????}36 ????public void setName(String name) {37 ????????this.name = name;38 ????}39 ????public String getDescription() {40 ????????return description;41 ????}42 ????public void setDescription(String description) {43 ????????this.description = description;44 ????}45 46 }

 1 package com; 2 ?3 public class Student { 4 ????public Student(int sid, String name, String description, Classes classes) { 5 ????????this.sid = sid; 6 ????????this.name = name; 7 ????????this.description = description; 8 ????????this.classes = classes; 9 ????}10 ????public Student(int sid, String name, Classes classes) {11 ????????this.sid = sid;12 ????????this.name = name;13 ????????this.classes = classes;14 ????}15 ????public Student()16 ????{}17 ????private int sid;18 ????private String name;19 ????private String description;20 ????private Classes classes;21 ????public Classes getClasses() {22 ????????return classes;23 ????}24 ????public void setClasses(Classes classes) {25 ????????this.classes = classes;26 ????}27 28 ????public int getSid() {29 ????????return sid;30 ????}31 ????public void setSid(int sid) {32 ????????this.sid = sid;33 ????}34 ????public String getName() {35 ????????return name;36 ????}37 ????public void setName(String name) {38 ????????this.name = name;39 ????}40 ????public String getDescription() {41 ????????return description;42 ????}43 ????public void setDescription(String description) {44 ????????this.description = description;45 ????}46 47 }

<?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> ???<!-- name：实体, table:表名 --> ???<class name="com.Classes" table="m2o_cla"> ???????<!-- name:主键的名字,column:主键数据库表列,identity自增 --> ???????<id name="cid"> ???????????<!-- Hibernate使用generator类来生成主键 --> ???????????<generator class="identity" /> ???????</id> ???????<!-- name：实体中的属性名，length:长度 ,column:表中的字段(实体属性和字段一致可省略)，type:类型(可不写由hiberbate自动匹配) --> ???????<property name="name" ?/> ???????<property name="description"/> ???????????????<!-- inverse:这个属性（stus） 是否为关系的维护方，默认值为false ???????????如果inverse设置为true，表示将由对方维护两者之间的关联关系 ????????--> ???????<!--cascade（级联）意思是指定两个对象之间的操作联动关系，对一个对象执行了操作之后，对其指定的级联对象也需要执行相同的操作 ???????????all-代表在所有的情况下都执行级联操作 ???????????none-在所有情况下都不执行级联操作 ???????????save-update-在保存和更新的时候执行级联操作 ???????????delete-在删除的时候执行级联操作 ????????--> ????????<!--lazy:延迟加载，默认true,如学生实体不调用班级实体信息，可以不用加载 ?--> ???????<set name="student" inverse="false" cascade="all" lazy="true"> ???????????<!-- 关系维护方的外键列 --> ???????????<key column="cid"></key> ???????????<one-to-many class="com.Student" /> ???????</set> ???</class></hibernate-mapping>

<?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> ???<!-- name：实体, table:表名 --> ???<class name="com.Student" table="m2o_stu"> ???????<!-- name:主键的名字,column:主键数据库表列,identity自增 --> ???????<id name="sid"> ???????????<!-- Hibernate使用generator类来生成主键 --> ???????????<generator class="identity" /> ???????</id> ???????<!-- name：实体中的属性名，length:长度 ,column:表中的字段(实体属性和字段一致可省略)，type:类型(可不写由hiberbate自动匹配) --> ???????<property name="name" ?/> ???????<property name="description"/> ???????????????<!-- 对应班级配置中的cid --> ???????<many-to-one name="classes" column="cid" cascade="save-update"></many-to-one> ???</class></hibernate-mapping>

 1 package com; 2 import org.hibernate.Session; 3 import org.hibernate.SessionFactory; 4 import org.hibernate.Transaction; 5 import org.hibernate.cfg.Configuration; 6 ?7 public class project_text { 8 ????public static Configuration cfg; 9 ????public static SessionFactory sessionFactory;10 ????static { 11 ????????cfg = new Configuration().configure("hibernate.cfg.xml");12 ????????sessionFactory = cfg.buildSessionFactory();13 ????}14 ????public static Session openSesson()15 ????{16 ????????return sessionFactory.openSession();17 ????}18 ????public static Transaction beginTransaction(Session session)19 ????{20 ????????return session.beginTransaction();21 ????}22 }

 1 package com; 2 ?3 import java.util.List; 4 ?5 import org.hibernate.Query; 6 import org.hibernate.Session; 7 import org.hibernate.SessionFactory; 8 import org.hibernate.Transaction; 9 import org.hibernate.cfg.Configuration;10 public class pro_text {11 12 ????public static void main(String[] args) {13 ????????project_text text_hibernate = new project_text();14 ????????Session textSession = ?text_hibernate.openSesson();15 ????????Transaction textTransaction = text_hibernate.beginTransaction(textSession);16 ????????text text1 =new text(2,"quanmina","123");17 ????????job job1 =new job(2,"adress","1111");18 ????????19 ????????textSession.save(text1);20 ????????21 ????????text text2 = new text();22 ????????text2.setId(1);23 ????????text2.setName("updatename");24 ????????text2.setPassword("123123");25 ????????textSession.update(text2);26 ????????27 // ???????text text3 = new text();28 // ???????text3.setId(3); 29 // ???????textSession.delete("3",text3);30 ????????31 ????????//text text4 = (text)textSession.get("text", 1);32 ????????//System.out.println("id:"+text4.getId()+"---name:"+text4.getName()+"----password:"+text4.getPassword());33 ????????Query ?query = textSession.createQuery("from text");34 ????????List<text> textList = query.list();35 ????????System.out.println("-*----------------------------------------*-");36 ????????for( text item ?: ?textList)37 ????????{38 ????????????System.out.println("id:"+item.getId()+"---name:"+item.getName()+"----password:"+item.getPassword()+"------"+item.get_job().getJobAdress());39 ????????}40 ????????41 ????????Query ?query1 = textSession.createQuery("from text,job where text.id=job.id");42 ????????List<text> textList1 = query1.list();43 ????????System.out.println("-*----------------------------------------*-");44 ????????for( text item ?: ?textList1)45 ????????{46 ????????????System.out.println("id:"+item.getId()+"---name:"+item.getName()+"----password:"+item.getPassword());47 ????????}48 ????????textSession.getTransaction().commit();49 ????????textSession.close();50 ????????51 ????????// TODO 自动生成的方法存根52 // ???????Configuration conf=new Configuration();//这个构造方法调用了一个受保护的构造方法：53 // ???????conf.configure("hibernate.cfg.xml");54 // ???????//创建工厂55 // ???????SessionFactory sf=conf.buildSessionFactory();56 // ???????//取得session57 // ???????Session session=sf.openSession();58 // ???????//开始事务59 // ???????session.beginTransaction();60 // ???????text text=new text(1,"quanmina","123");61 // ???????session.save(text);62 // ???????System.out.println("保存成功");63 // ???????session.getTransaction().commit();64 // ???????session.close();65 // ???????sf.close();66 ????}67 68 }

 1 package com; 2 ?3 import java.util.LinkedList; 4 import java.util.List; 5 ?6 import org.hibernate.Query; 7 import org.hibernate.Session; 8 import org.hibernate.Transaction; 9 10 public class StudClassesMian {11 12 ????public static void main(String[] args) {13 ????????// TODO 自动生成的方法存根14 ????????project_text text_hibernate = new project_text();15 ????????Session session = ?text_hibernate.openSesson();16 ????????Transaction transaction = text_hibernate.beginTransaction(session);17 ????????Student student = new Student();18 ????????student.setName("asfd");19 ????????Classes classes = new Classes();20 ????????classes.setName("12期");21 ?????????//创建班级与学生之间的关联22 ????????student.setClasses(classes); ?//通过学生建立的关联 ?23 ?????????//session.save(student);24 ?????????transaction.commit();25 ????????????String hqlS= "select s.sid,s.name,c.cid,c.name from com.Student as s,com. Classes as c where s.classes = c.cid";26 ????????????Query query = session.createQuery(hqlS);27 ????????????List<Object> list_stu = query.list();28 ????????????List<Student> listResult= new LinkedList<Student>();29 ????????????for(int i=0;i<list_stu.size();i++)30 ????????????{31 ????????????????Object[] obj = (Object[])list_stu.get(i); ???32 ????????????????Classes cls = new Classes((int)obj[2],obj[3].toString()); ?//利用构造函数将查询结构保存到实体类中，方便数据使用/33 ????????????????Student stu = new Student((int)obj[0],obj[1].toString(),cls);34 ????????????????listResult.add(stu);35 ????????????}36 ????????????for(Student item : listResult)37 ????????????{38 ????????????????System.out.println(item.getSid()+"=="+item.getName()+"=="+item.getClasses().getCid()+"=="+item.getClasses().getName());39 ????????????}40 ????????????List<Object> list = query.list();41 ????????????for(int i=0;i<list.size();i++)42 ????????????{43 ????????????????Object[] obj = (Object[])list.get(i);44 ????????????????System.out.println(obj[0]+"==="+obj[1]+"==="+obj[2]+"==="+obj[3]+"===");45 ????????????}46 ????????????System. out.println(list.size());47 ????????????String SQLStr= "select s.sid as sid,s.name as sname,c.cid as cid,c.name as cname from m2o_stu as s, m2o_cla as c where s.cid = c.cid";48 ????????????Query querySQL = session.createSQLQuery(SQLStr);49 ????????????List lsitSQL = querySQL.list();50 ????????????System. out.println(lsitSQL.size());51 ?????????session.close();52 ????}53 54 }