Hibernate-Entity.hbm.xml实现-intellij-kotlin入门级-阿里云开发者社区

个人博客
 项目地址-码云

intellij新建Maven项目
在src/resource下新建hibernate.cfg.xml文件，一定要在src/resource目录下，否则会报无法定位资源文件的错误。

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--数据库url，以及防止中文乱码-->
        <property name="connection.url">jdbc:mysql://localhost:3306/hibernate-final?useUnicode=true&characterEncoding=UTF-8</property>
        <!--Mysql驱动-->
        <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
        <!--Mysql用户名-->
        <property name="connection.username">root</property>
        <!--Mysql密码-->
        <property name="connection.password">rootPwd</property>

        <!--方言-->
        <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
        <!--调试时显示sql语句-->
        <property name="show_sql">true</property>
        <!--格式化调试时输出的sql语句-->
        <property name="format_sql">true</property>

        <!-- DB schema will be updated if needed -->
        <!--create表结构每次发生改变都会删除原来的表，创建新的表。update是在原有的表上进行更新，保留数据-->
        <property name="hbm2ddl.auto">update</property>
        <!--<property name="hbm2ddl.auto">create</property>-->

        <!--映射文件-->
        <mapping resource="StudentEntity.hbm.xml"/>
    </session-factory>
</hibernate-configuration>

不要使用intellij的Add Framework Support，可能是intellij的hibernate版本太低了，使用这种方式生成数据库表的时候会报错，"type"在mysql高版本中已经被删除。
在项目的pom文件中添加hibernate依赖

      <!--hibernate依赖-->
        <dependency>
            <groupId>org.hibernate</groupId>
            <artifactId>hibernate-core</artifactId>
            <version>4.3.11.Final</version>
        </dependency>
        <!--单元测试依赖-->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <version>4.10</version>
        </dependency>
        <!--mysqlJDBC依赖-->
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>5.1.39</version>
        </dependency>

新建持久化类

package Entity;


/**
 * Created by futao on 2017/9/24.
 */
public class Student {
    //JavaBean(持久化类)编写规范
    //1.公有的类
    //2.私有属性
    //3.提供公有的不带参数的默认构造方法
    //4.私有属性的公有getter和setter
    //5.为方便实例化对象，一般生成一个带参的构造方法

    //设置public static final String的意义在于：比如 .add(Restrictions.eq())的时候，可以直接通过实体的类型点出来，而不用手动输入，这样避免了手动输入发生错误的情况
    private int sid;
    public static final String _sid = "sid";
    private String name;
    public static final String _name = "name";
    private String gender;
    public static final String _gender = "gender";
    private Timestamp birthday;
    public static final String _birthday = "birthday";
    private String address;
    public static final String _address = "address";
    private String tel;
    public static final String _tel = "tel";

    public Student(){ }

    public Student(int sid, String name, String gender, String birthday, String address, String tel) {
        this.sid = sid;
        this.name = name;
        this.gender = gender;
        this.birthday = birthday;
        this.address = address;
        this.tel = tel;
    }

    public int getSid() {
        return sid;
    }

    public void setSid(int sid) {
        this.sid = sid;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public String getGender() {
        return gender;
    }

    public void setGender(String gender) {
        this.gender = gender;
    }

    public String getBirthday() {
        return birthday;
    }

    public void setBirthday(String birthday) {
        this.birthday = birthday;
    }

    public String getAddress() {
        return address;
    }

    public void setAddress(String address) {
        this.address = address;
    }

    public String getTel() {
        return tel;
    }

    public void setTel(String tel) {
        this.tel = tel;
    }
}

在src/resource文件夹下创建实体映射文件StudentEntity.hbm.xml，maven项目的配置文件应该都应该放在这个文件夹下，否则都会报错。

<?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">
<hibernate-mapping>

    <class name="Entity.Student" table="t_student">
        <id name="sid">
            <column name="sid" sql-type="int(11)"/>
            <generator class="native"/>
        </id>
        <property name="name">
            <column name="name" sql-type="varchar(255)" not-null="true"/>
        </property>
        <property name="birthday">
            <column name="birthday" sql-type="varchar(255)" not-null="true"/>
        </property>
        <property name="address">
            <column name="address" sql-type="varchar(255)" not-null="false"/>
        </property>
    </class>
</hibernate-mapping>

在hibernate主配置文件中添加实体映射文件

  <!--映射文件-->
        <mapping resource="StudentEntity.hbm.xml"/>

测试

package Entity

import org.hibernate.cfg.Configuration
import org.junit.Test

@Suppress("DEPRECATION")
/**
 * Created by futao on 2017/9/24.
 */
class t{

    @Test
    fun testInit(){
        //加载配置文件
        val configuration=Configuration().configure()
        //创建会话工厂
        val sessionFactory=configuration.buildSessionFactory()
        //创建会话
        val session=sessionFactory.openSession()
        //开启事务
        val transaction=session.beginTransaction()

        //crud
        session.save(Student(1,"熊小二","男", "2017-9-24","上海市小二房","1887978252"))

        //提交事务
        transaction.commit()
        //关闭会话
        session.close()
        //关闭会话工厂
        sessionFactory.close()
    }

}

基础版完成 ↑↑↑↑↑↑↑

Hibernate执行流程

session简单地理解就是一个操作数据库的对象
hibernate的操作必须包装在事务当中，否则操作不会同步到数据库（或者使用doWord()的方式）

创建session对象的两种方式

val session=sessionFactory.openSession()
val session=sessionFactory.currentSession
使用第二种方式获得session需要在hibernate主配置文档中进行配置

 <!-- Enable Hibernate's automatic session context management -->
        <property name="current_session_context_class">thread</property>

hbm常用配置

mapping

class

主键生成策略

基本类型

timestamp时间戳

image.png

长文本

//Entity
  private Blob picture;//照片,长文本
    public static final String _picture = "picture";


//hbm.xml
       <property name="picture">
            <column name="picture" sql-type="longblob" not-null="false"/>
        </property>


//Test    存
 val f= File("d:"+File.separator+"banner.png")
        val input=FileInputStream(f)
        val blob=Hibernate.getLobCreator(session).createBlob(input, input.available().toLong())
        session.save(Student(5,"熊","男", Timestamp(DateTime.now().millis) ,"上海市小二房","1887978252",blob))


//    取
 val entity = session.get(Student::class.java, 4) as Student
        //获得Blob对象
        val pic= entity.picture
        //获得照片的输入流
        val inPut=pic.getBinaryStream()
        //创建输出流
        val file = File("d:"+File.separator+"bannerNew.png")
        //获得输出流
        val outPut=FileOutputStream(file)
        //创建缓冲区
        var buff = ByteArray(inPut.available())
        inPut.read(buff)
        outPut.write(buff)
        inPut.close()
        outPut.close()

组件属性

<?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">
<hibernate-mapping>

    <class name="Entity.Student" table="t_student">
        <id name="sid">
            <column name="sid" sql-type="int(11)"/>
            <generator class="native"/>
        </id>
        <property name="name">
            <column name="name" sql-type="varchar(255)" not-null="true"/>
        </property>
        <property name="birthday">
            <column name="birthday" sql-type="timestamp" not-null="true"/>
        </property>
        <!--<property name="address">-->
            <!--<column name="address" sql-type="varchar(255)" not-null="false"/>-->
        <!--</property>-->
        <property name="picture">
            <column name="picture" sql-type="longblob" not-null="false"/>
        </property>
        <!--组件属性-->
        <component name="addressEntity" class="Entity.Address">
            <property name="postCode">
                <column name="postCode"/>
            </property>
            <property name="phone">
                <column name="phone"/>
            </property>
            <property name="address">
                <column name="address"/>
            </property>
        </component>
    </class>
</hibernate-mapping>

组件属性的所有property会在实体(Student)对应的表中生成相应的字段