dljd_(008-010)hibernate_第一个程序

Posted 2021-01-25 1024军团

一、定义实体类

　　1.1新建一个java project项目

　　1.2新建lib文件夹并导入hibernate项目所必须的外部jar文件

　　1.3实体类编写　　

package edu.aeon.beans;
/**
 * [说明]:学生实体(bean)类
 * @author aeon
 *
 */
public class Student {
    /**用户id*/
    private Integer stuId;
    /**用户名*/
    private String stuName;
    /**用户年龄*/
    private int stuAge;
    /**用户分数*/
    private double stuScore;
    /**空构造器*/
    public Student() {
        super();
    }
    /**带惨构造、没有stuId是因为最后这个用户id我们自动生成*/
    public Student(String stuName, int stuAge, double stuScore) {
        super();
        this.stuName = stuName;
        this.stuAge = stuAge;
        this.stuScore = stuScore;
    }
    /**setter/getter*/
    public Integer getStuId() {
        return stuId;
    }
    public void setStuId(Integer stuId) {
        this.stuId = stuId;
    }
    public String getStuName() {
        return stuName;
    }
    public void setStuName(String stuName) {
        this.stuName = stuName;
    }
    public int getStuAge() {
        return stuAge;
    }
    public void setStuAge(int stuAge) {
        this.stuAge = stuAge;
    }
    public double getStuScore() {
        return stuScore;
    }
    public void setStuScore(double stuScore) {
        this.stuScore = stuScore;
    }
    /**重写toString方法*/
    @Override
    public String toString() {
        return "Student [stuId=" + stuId + ", stuName=" + stuName + ", stuAge=" + stuAge + ", stuScore=" + stuScore
                + "]";
    }
}

 1.4映射实体类到数据库表

　　dtd头文件可以直接从导入的包中找！　　

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC 
    "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- 
    映射文件的作用:
        1.映射实体类到数据库表
        2.映射实体类属性到数据库表字段
 -->
<hibernate-mapping package="edu.aeon.beans.Student">
    <!-- 1.映射实体类到数据库表 -->
    <class  table="t_student">
    <!-- 2.映射实体类属性到数据库表字段 -->
        <id name="stuId">
            <generator class="native"/>
        </id>
    <property name="stuName" length="16" column="stu_name" />
    <property name="stuAge"  column="stu_age" />
    <property name="stuScore" length="6" column="t_score" />
    </class>
</hibernate-mapping>