1.是什么?

Hibernate是一个操作数据库的框架，实现了对JDBC的封装
Hibernate与JDBC的对比

2.代码实现

需求1:使用hibernate实现(连接数据库+自动建表)
第一步:建bean(User.java)

public class User {
    private int uid;
    private String uname;
    private String upw;
    //省略Getter&Setter
}

第二步:建bean的映射文件(User.hbm.xml)

<?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>
        <class  
            name="com.yy1811.hibernate.bean.User" 
            table="user">
            <id
            name="uid"
            column="uid"
            length="36">
            <generator
                class="assigned" />
            </id>
                <property
                    name="uname"
                    column="uname"
                    update="true"
                    insert="true"
                    length="200"
                    not-null="true" />
                <property
                    name="upw"
                    column="upw"
                    update="true"
                    insert="true"
                    length="200"
                    not-null="true" />
        </class>
</hibernate-mapping>

第三步:建hibernate的配置文件(hibernate.cfg.xml)

<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--连接数据库-->
        <property name="hibernate.connection.url">
            jdbc:mysql://localhost:3306/test
        </property>
        <property name="hibernate.connection.driver_class">
            com.mysql.jdbc.Driver
        </property>
        <property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
        <property name="hibernate.connection.username">root</property>
        <property name="hibernate.connection.password">root</property>  
        <!-- 是否启动表结构自动生成 -->
        <property name="hbm2ddl.auto">update</property>
        <!-- 是否在控制台显示SQL语句 -->
        <property name="show_sql">true</property>
        <!-- 下面这一句是重点!!!特别是路径,千万别搞错 -->
        <mapping resource="com/yy1811/hibernate/bean/User.hbm.xml" />
    </session-factory>
</hibernate-configuration>