Hibernate入门笔记
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import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.JoinColumn;
import javax.persistence.ManyToOne;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;
@Entity //注解Entity表示该类能被Hibernate持久化
@Table(name = "tb_cat") //指定该Entity对应的数据表名
public class Cat {
@Id //指定该列为主键。主键类型最好不要使用int等原始类型
@GeneratedValue(strategy = GenerationType.AUTO) //主键类型auto表示该主键为自增长型
private Integer id;
@Column(name = "name") //指定该属性对应的数据库表的列为name,列名与属性名一样时这句注解可省略
private String name;
@Column(name = "description")
private String description;
@ManyToOne //指定实体类之间的关系,本例表示多对一关系
@JoinColumn(name = "mother_id")
private Cat mother;
@Temporal(TemporalType.TIMESTAMP)//日期类型(DATE,TIME或TIMESTEMP)
@Column(name = "birthday")
private Date birthday;
//getters and setters
public Integer getId() {
return id;
}
public void setId(Integer id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public String getDescription() {
return description;
}
public void setDescription(String description) {
this.description = description;
}
public Cat getMother() {
return mother;
}
public void setMother(Cat mother) {
this.mother = mother;
}
public Date getBirthday() {
return birthday;
}
public void setBirthday(Date birthday) {
this.birthday = birthday;
}
}
<!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>
<!-- 配置JDBC -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://localhost:3306/hibernate</property>
<property name="connection.username">root</property>
<property name="connection.password">123456</property>
<!-- 指定使用MySQL数据库格式的SQL语句 -->
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<!-- 指定在控制台打印生成的SQL语句 -->
<property name="show_sql">true</property>
<!-- 指定Hibernate启动时自动创建表结构 -->
<property name="hbm2ddl.auto">create</property>
<!-- 加上这一句以防止未知错误 -->
<property name="current_session_context_class">thread</property>
<!-- 指定Cat类为Hibernate实体类 -->
<mapping class="com.levice.firsthibernate.bean.Cat"/>
</session-factory>
</hibernate-configuration>
create database hibernate;
package com.levice.firsthibernate.util;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.AnnotationConfiguration;
@SuppressWarnings("deprecation")
public class HibernateUtil {
private static final SessionFactory sessionFactory;
static{
try{
sessionFactory = new AnnotationConfiguration().configure().buildSessionFactory();
}catch(Throwable ex){
System.err.println("Initial SessionFactory creation failed.");
throw new ExceptionInInitializerError(ex);
}
}
public static SessionFactory getSessionFactory(){
return sessionFactory;
}
}
package com.levice.firsthibernate.test;
import java.awt.Font;
import java.util.Date;
import java.util.List;
import javax.swing.JOptionPane;
import org.hibernate.Session;
import org.hibernate.Transaction;
import com.levice.firsthibernate.bean.Cat;
import com.levice.firsthibernate.util.HibernateUtil;
public class CatTest {
public static void main(String[] args) {
// TODO Auto-generated method stub
/*初始化几只Cat的信息*/
Cat mother = new Cat();
mother.setName("Mother White");
mother.setDescription("This is mother cat");
mother.setBirthday(new Date());
Cat kitty = new Cat();
kitty.setMother(mother);
kitty.setName("Kitty");
kitty.setDescription("This is Kitty");
kitty.setBirthday(new Date());
Cat tom = new Cat();
tom.setMother(mother);
tom.setName("Tom");
tom.setDescription("This is Tom");
tom.setBirthday(new Date());
@SuppressWarnings("static-access")
Session session = new HibernateUtil().getSessionFactory().openSession(); //获取session并open,开启一个Hibernate会话
Transaction trans = session.beginTransaction(); //开启一个事务
session.persist(mother); //将mother保存到数据库
session.persist(kitty);
session.persist(tom);
@SuppressWarnings("all")
List<Cat> catList = session.createQuery(" from Cat ").list(); //查询数据库中所有的猫
StringBuffer result = new StringBuffer();
result.append("all cats: \\r\\n\\r\\n");
for (Cat cc : catList) {
result.append("name:" + cc.getName() + "\\n");
result.append("mother:" + (cc.getMother() == null ? "null" : cc.getMother().getName()) + "\\n");
result.append("description:" + cc.getDescription() + "\\r\\n\\r\\n");
}
trans.commit(); //提交事务
session.close(); //关闭Hibernate会话
//用Swing显示查询结果
JOptionPane.getRootFrame().setFont(new Font("Arial", Font.BOLD, 14));
JOptionPane.showMessageDialog(null, result.toString());
}
}
Hibernate: alter table tb_cat drop foreign key FK_dix3h50rxo8ahrcu5roir75n1
Hibernate: drop table if exists tb_cat
Hibernate: create table tb_cat (id integer not null auto_increment, birthday datetime, description varchar(255), name varchar(255), mother_id integer, primary key (id))
Hibernate: alter table tb_cat add constraint FK_dix3h50rxo8ahrcu5roir75n1 foreign key (mother_id) references tb_cat (id)
Hibernate: insert into tb_cat (birthday, description, mother_id, name) values (?, ?, ?, ?)
Hibernate: insert into tb_cat (birthday, description, mother_id, name) values (?, ?, ?, ?)
Hibernate: insert into tb_cat (birthday, description, mother_id, name) values (?, ?, ?, ?)
Hibernate: select cat0_.id as id1_0_, cat0_.birthday as birthday2_0_, cat0_.description as descript3_0_, cat0_.mother_id as mother_i5_0_, cat0_.name as name4_0_ from tb_cat cat0_