2021-09-22
作者：互联网
Hibernate实现增改删查
文章目录
前言
Hibernate作为轻量级框架可自动在数据库生成表一、什么是Hibernate
Hibernate是一个开放源代码的对象关系映射框架，它对JDBC进行了非常轻量级的对象封装，它将POJO与数据库表建立映射关系，是一个全自动的orm框架，hibernate可以自动生成SQL语句，自动执行，使得Java程序员可以随心所欲的使用对象编程思维来操纵数据库。 Hibernate可以应用在任何使用JDBC的场合，既可以在Java的客户端程序使用，也可以在Servlet/JSP的Web应用中使用，最具革命意义的是，Hibernate可以在应用EJB的JavaEE架构中取代CMP，完成数据持久化的重任。
二、创建Hibernate步骤
1.创建空Java项目
导入hibernate包
项目结构如下：
2.在src中创建hibernate.cfg.xml
右击src选择新建，选择其他，输入hibernate，点击带有cfg.xml的文件，点击完成
3.修改cfg文件
hibenate.cfg.xml代码如下：
<?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>
<property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="hibernate.connection.password">root</property>
<!-- jdbc:mysql://localhost:端口号/数据库名 -->
<property name="hibernate.connection.url">jdbc:mysql://localhost:3306/mycsdb</property>
<property name="hibernate.connection.username">root</property>
<!-- MySQL5InnoDB为数据库方言 -->
<property name="hibernate.dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
<property name="hibernate.show_sql">true</property>
<property name="hibernate.hbm2ddl.auto">update</property>
<mapping resource="pojo/Authors.hbm.xml"/>
<mapping class="pojo.Books"/>
</session-factory>
</hibernate-configuration>
4.在src中创建pojo包
创建两个java类：
Authors.java类：
package pojo;
import java.util.ArrayList;
import java.util.List;
public class Authors {
//write
//pojo中需要写属性，getter和setter toString()都可以自己生成
private int authorid;
private String authorname;
private List<Books> list = new ArrayList();
public Authors() {}
//auto
public Authors(int authorid, String authorname, List<Books> list) {
super();
this.authorid = authorid;
this.authorname = authorname;
this.list = list;
}
public List<Books> getList() {
return list;
}
public void setList(List<Books> list) {
this.list = list;
}
public int getAuthorid() {
return authorid;
}
public void setAuthorid(int authorid) {
this.authorid = authorid;
}
public String getAuthorname() {
return authorname;
}
public void setAuthorname(String authorname) {
this.authorname = authorname;
}
@Override
public String toString() {
return "Authors [authorid=" + authorid + ", authorname=" + authorname + ", list=" + list + "]";
}
}
Books.java类：
package pojo;
public class Books {
private int bookid;
private String bookname;
public Books() {};
public Books(int bookid,String boookame){
super();
this.bookid = bookid;
this.bookname = bookname;
}
public int getBookid() {
return bookid;
}
public void setBookid(int bookid) {
this.bookid = bookid;
}
public String getBookname() {
return bookname;
}
public void setBookname(String bookname) {
this.bookname = bookname;
}
@Override
public String toString() {
return "Books [bookid=" + bookid + ", bookname=" + bookname + "]";
}
}
5.HibernateList
在src中创建test包，在包中创建TestList类：
package test;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.Transaction;
import org.junit.Test;
import pojo.Authors;
import pojo.Books;
import util.HibernateUtil;
public class TestList {
@Test
public void testOne() {
//1.获取会话Session
Session session = HibernateUtil.getSessionFactory().openSession();
// Session session1 = HibernateUtil.getSession();
//2.开启事务
Transaction tx = session.beginTransaction();
//3.添加数据
Books book1 = new Books();//
book1.setBookname("白夜行");
book1.setBookid(1);
Books book2 = new Books();
book2.setBookname("解忧杂货店");
book2.setBookid(2);
Authors author = new Authors();//一
author.setAuthorname("东野圭吾");
//4.关联
author.getList().add(book1);
author.getList().add(book2);
//5.保存数据
session.save(author);
session.save(book1);
session.save(book2);
//6.事务提交
tx.commit();
//7.关闭资源
session.close();
}
@Test
public void testQuery() {
Session session = HibernateUtil.getSessionFactory().openSession();
Query query = session.createQuery("From pojo.Authors");
List list = query.list();
for(Iterator itr = list.iterator();itr.hasNext();) {
Authors a = (Authors) itr.next();
//借助pojo中的toString()方法打印内容
System.out.print(a.toString());
}
}
}
6.写工具类
在src中创建util类，创建HibernateUtil工具类：
package util;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
public class HibernateUtil {
static SessionFactory sf;
static {
sf = new Configuration().configure()
.buildSessionFactory();
}
public static SessionFactory getSessionFactory() {
return sf;
}
public static Session getSession() {
return sf.openSession();
}
}
7.生成hbm文件并且配置
将Authors和Books合并：
<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<!-- Generated 2021-9-22 21:47:19 by Hibernate Tools 3.5.0.Final -->
<hibernate-mapping>
<class name="pojo.Authors" table="AUTHORS">
<id name="authorid" type="int">
<column name="AUTHORID" />
<generator class="assigned" />
</id>
<property name="authorname" type="java.lang.String">
<column name="AUTHORNAME" />
</property>
<list name="list" cascade="all">
<key column="AUTHORID"/>
<list-index column="BOOKID"></list-index>
<one-to-many class="pojo.Books" />
</list>
</class>
<class name ="pojo.Books" table= "BOOKS">
<<id name="bookid" type ="int">
<column name ="BOOKID"/>
<generator class="assigned"/>
</id>
<property name="bookname" type="java.lang.String">
<column name="BOOKNAME"></column>
</property>
</class>
</hibernate-mapping>
测试
打开Navicat查看表：
总结
以上是Hibernate自动向数据库插入数据，如有错误请改正。
标签：hibernate,22,09,list,Hibernate,2021,Authors,import,public 来源： https://blog.csdn.net/weixin_42620428/article/details/120425014