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Hibernate学习之类级别注解

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类级别注解:

  1. @Entity        实体:表示映射实体类,使用@Entity时必须指定实体类的主键属性

                   @Entity(name="")

                   name:可选,对应数据库中的一张表。若表名与实体名相同则可省略

  2. @Table         表:表示实体类对应的数据库表的信息   

                   @Table(name="", catalog="", schema="")

                   name:可选,映射表的名称,默认表名与实体名称一致,只有在不一致的情况下才需指定表名

                   catalog:可选,表示目录名称,默认为Catalog("")

                   schema:可选,表示模式名称,默认为Schema("")

  3. @Embeddable      嵌入类:表示一个非Entity类可以嵌入到一个Entity类中作为属性而存在

实例

1.项目结构

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2.pom.xml

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
  
  	<modelVersion>4.0.0</modelVersion>

	<groupId>org.hibernate</groupId>
	<artifactId>Hibernate-ClassAnnotation</artifactId>
	<version>0.0.1-SNAPSHOT</version>
	<packaging>jar</packaging>

	<properties>
		<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
		<hibernate.version>5.1.7.Final</hibernate.version>
	</properties>

	<dependencies>
		<!-- junit -->
		<dependency>
			<groupId>junit</groupId>
			<artifactId>junit</artifactId>
			<version>4.12</version>
			<scope>test</scope>
		</dependency>
		<!-- Hibernate -->
		<dependency>
		    <groupId>org.hibernate</groupId>
		    <artifactId>hibernate-core</artifactId>
		    <version>${hibernate.version}</version>
		</dependency>
		<!-- MySQL -->
		<dependency>
		    <groupId>mysql</groupId>
		    <artifactId>mysql-connector-java</artifactId>
		    <version>5.1.42</version>
		</dependency>
	</dependencies>
</project>

3.Address.java

package org.hibernate.model;

import javax.persistence.Embeddable;

@Embeddable
public class Address {

	private String postcode;// 邮编
	private String address;// 地址
	private String telephone;// 电话
	
	public String getPostcode() {
		return postcode;
	}
	
	public void setPostcode(String postcode) {
		this.postcode = postcode;
	}
	
	public String getAddress() {
		return address;
	}
	
	public void setAddress(String address) {
		this.address = address;
	}
	
	public String getTelephone() {
		return telephone;
	}
	
	public void setTelephone(String telephone) {
		this.telephone = telephone;
	}
	
}

4.Student.java

package org.hibernate.model;

import java.util.Date;

import javax.persistence.Entity;
import javax.persistence.Id;
import javax.persistence.Table;

@Entity
@Table(name="t_student")
public class Student {

	private long id;// 学号
	private String name;// 姓名
	private Date birthday;// 出生日志
	private String sex;// 性别
	private Address address;// 地址
	
	public Student() {
	}
	
	public Student(long id, String name, Date birthday, String sex, Address address) {
		this.id = id;
		this.name = name;
		this.birthday = birthday;
		this.sex = sex;
		this.address = address;
	}
	
	@Id
	public long getId() {
		return id;
	}
	
	public void setId(long id) {
		this.id = id;
	}
	
	public String getName() {
		return name;
	}
	
	public void setName(String name) {
		this.name = name;
	}
	
	public Date getBirthday() {
		return birthday;
	}
	
	public void setBirthday(Date birthday) {
		this.birthday = birthday;
	}
	
	public String getSex() {
		return sex;
	}
	
	public void setSex(String sex) {
		this.sex = sex;
	}

	public Address getAddress() {
		return address;
	}

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

5.hibernate.cfg.xml

<?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>

	<!-- SessionFactory配置 -->
	<session-factory>
		<!-- 数据库常用配置 -->		
		<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
		<property name="connection.username">root</property>
		<property name="connection.password">***</property>
		<property name="connection.url">
			jdbc:mysql:///hibernate?useSSL=true&amp;characterEncoding=UTF-8
		</property>
		<property name="dialect">org.hibernate.dialect.MySQL5InnoDBDialect</property>
		<!-- 开发常用配置 -->
		<property name="show_sql">true</property>
        <property name="format_sql">true</property> <property name="hbm2ddl.auto">create</property> <!-- 引入映射类 --> <mapping class="org.hibernate.model.Student"/> </session-factory> </hibernate-configuration>

6.TestClassAnnotation.java

package org.hibernate.test;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;

public class TestClassAnnotation {
  
	private SessionFactory sessionFactory;
	private Session session;
	private Transaction transaction;

	@Before
	public void before() {
		
		sessionFactory = new Configuration().configure().buildSessionFactory();// 创建SessionFactory对象
		session = sessionFactory.openSession();// 获取Session对象
		transaction = session.beginTransaction();// 开启事务
		
	}
	
	@After
	public void after() {
		
		transaction.commit();// 提交事务
		session.close();// 关闭Session
		sessionFactory.close();// 关闭SessionFactory
		
	}
	
	@Test
	public void testAnnotation() {
		
		System.out.println("执行成功...");
		
	}
	
}

7.效果预览

  7.1 执行testAnnotation()方法-控制台

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  7.2 表结构

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参考:http://www.imooc.com/video/10073

Hibernate学习之类级别注解