Hibernate入門案例及增刪改查

標籤：

一、Hibernate入門案例剖析：

①建立實體類Student 並重寫toString方法

public class Student {    private Integer sid;    private Integer age;    private String name;    public Integer getSid() {        return sid;    }    public void setSid(Integer sid) {        this.sid = sid;    }    public Integer getAge() {        return age;    }    public void setAge(Integer age) {        this.age = age;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    @Override    public String toString() {        return "Student [sid=" + sid + ", age=" + age + ", name=" + name + "]";    }        }

② 建立學生對象 並賦值

 

 ③引入jar包

④ 構建大配置<hibernate.cfg.xml>

可分為以下步驟：

1.串連資料庫的語句

2.sql方言

3.可省的配置(show_sql、format_sql 取值為true)

4.讓程式產生底層資料表(hbm2ddl.auto) update/create。create是每次將資料表刪除後，重新建立

5.關聯小配置

<mapping resource="cn/happy/entity/Student.hbm.xml" />

關鍵代碼如下：

<?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>        <!-- Database connection settings 資料庫連接設定-->        <!-- 驅動類 -->        <property name="connection.driver_class">oracle.jdbc.OracleDriver</property>        <!-- url地址 -->        <property name="connection.url">jdbc:oracle:thin:@localhost:1521:orcl3</property>        <property name="connection.username">wj</property>        <property name="connection.password">9090</property>        <!-- SQL dialect  (SQL 方言) -->        <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>        <!--在控制台列印多工緩衝的SQL語句 -->        <property name="show_sql">true</property>                        <!-- 格式化顯示SQL -->        <!-- <property name="format_sql">true</property> -->                        <!-- 自動產生student表 -->         <property name="hbm2ddl.auto">update</property>          <!-- 關聯小配置 -->        <mapping resource="cn/happy/entity/Student.hbm.xml" />        <!-- <mapping class="cn.happy.entity.Grade"/> -->            </session-factory></hibernate-configuration>

⑤ 構建小配置(Student.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.happy.entity">        <class name="Student" table="STUDENT">        <id name="sid" column="SID">           <!-- 主鍵建置原則：native:           native:如果後台是Oracle                                 後台是MySQL，自動應用自增                                                                            assigned:程式員給主鍵賦值              uuid:32位的16進位數              sequence              native                          -->                        <generator class="assigned">               <param name="sequence">SEQ_NUM</param>            </generator>        </id>       <!--  <version name="version"></version> -->        <property name="name" type="string" column="NAME"/>        <property name="age"/>    </class></hibernate-mapping>

⑥ 工具類HibernateUtil、構建私人靜態Configuration、SessionFactory對象、定義返回session以及關閉session的方法

private static Configuration cf=new Configuration().configure();    private static SessionFactory sf=cf.buildSessionFactory();        //方法返回session    public static Session getSession(){        return sf.openSession();    }        //關閉Session        public static void CloseSession(){        getSession().close();    }

⑦測試類別【增刪改查】 使用標記After、Before可簡化代碼

package cn.happy.test;import org.hibernate.Session;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.junit.After;import org.junit.Before;import org.junit.Test;import cn.happy.entity.Student;import cn.happy.util.HibernateUtil;public class Test1 {            Session session;    Transaction tx;     @After    public void afterTest(){        tx.commit();        HibernateUtil.CloseSession();    }    @Before    public void initData(){        session=HibernateUtil.getSession();        tx=session.beginTransaction();    }        /*     * get方法查詢     */    @Test    public void getData(){        Student stu=(Student)session.get(Student.class, 3);        System.out.println(stu);    }            /*     * 增加     */        @Test    public void addData(){        Student stu=new Student();        stu.setSid(12);        stu.setAge(11);        stu.setName("李小龍1");    //讀取大設定檔 擷取串連資訊        Configuration cfg=new Configuration().configure();        //建立SessionFactory        SessionFactory fa=cfg.buildSessionFactory();    //加工Session    Session se=fa.openSession();    Transaction tx = se.beginTransaction();    //儲存    se.save(stu);    //事務提交    tx.commit();    se.close();        System.out.println("Save ok!");            }         /*     * 刪除     */    @Test    public void delData(){        Session session=HibernateUtil.getSession();        Student stu=new Student();        stu.setSid(2);        Transaction tx=session.beginTransaction();        session.delete(stu);        tx.commit();        HibernateUtil.CloseSession();        System.out.println("del ok!");    }        /*     * 修改     */    @Test    public void updateData(){        Session session=HibernateUtil.getSession();                Student stu=(Student)session.load(Student.class,3);        stu.setName("呵呵");        Transaction tx=session.beginTransaction();        session.update(stu);        tx.commit();        HibernateUtil.CloseSession();        System.out.println("update ok!");    }            }

 

Hibernate入門案例及增刪改查