Hibernate 映射文件使用方式案例

小咪咪 2022-06-05 22:21 180阅读 0赞

**Hibernate 映射文件使用方式案例**

本案例使用的hibernate版本为 hibernate-release-5.2.10.Final

为了测试，本案例在mysql数据库中创建了一个db数据库。

创建一个java项目：项目的结构如下：（lib文件夹用于存放jar包）

![Center][]

lib目录下则是hibernate5需要的jar包（注需要将jar加载到项目中：选中jar包右键 --》BuildPath--》Add to Build Path）  
![Center 1][]  
log4j.properties为日志配置文件（需要加载配置junit），此项目可以不需要日志，使用日志只是为了观察方便。  
注：junit配置可以参考 [http://blog.csdn.net/benxiaohai888/article/details/78231911][http_blog.csdn.net_benxiaohai888_article_details_78231911]

由于在主配置文件配置了字段创建数据表的配置，所以第一次加载时就会自动创建数据表

配置的代码：

<property name="hbm2ddl.auto">update</property>

接下来是示例代码：

1、主配置文件 hibernate.cfg.xml

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE hibernate-configuration PUBLIC
    	"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    	"http://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.url">jdbc:mysql://localhost:3306/db?characterEncoding=utf8</property>
    		
    		<property name="hibernate.connection.username">root</property>
    		
    		<property name="hibernate.connection.password"></property>
    
    		
    		<property name="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</property>
    
    		
    
    		
    		<property name="hibernate.show_sql">true</property>
    		
    		<property name="hibernate.format_sql">true</property>
    		
    		<property name="hbm2ddl.auto">update</property>
    		
    		<property name="hibernate.current_session_context_class">thread</property>
    		
    		<property name="hibernate.connection.isolation">4</property>
    
    
    		
    		<mapping resource="cn/sz/entity/User.hbm.xml" />
    
    
    	</session-factory>
    </hibernate-configuration>

2、工具类（获取Session）HibernateUtil.java

package cn.sz.utils;
    
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.cfg.Configuration;
    
    public class HibernateUtil {
    	public static Session getSession() {
    		Session session = null;
    		// 创建一个读取主配置文件的对象
    		Configuration cfg = new Configuration();
    		// 读取主配置文件
    		cfg.configure();
    		// 创建Session工厂
    		SessionFactory factory = cfg.buildSessionFactory();
    		// 打开Session
    		// session = factory.openSession();
    		// 如果在主配置文件将session绑定到线程中，所以可以从线程中取出session
    		session = factory.getCurrentSession();
    		return session;
    	}
    }

3、日志文件 log4j.properties

log4j.rootLogger=DEBUG,console,FILE
    log4j.appender.console=org.apache.log4j.ConsoleAppender
    log4j.appender.console.threshold=INFO
    log4j.appender.console.layout=org.apache.log4j.PatternLayout
    log4j.appender.console.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} [%5p] - %c -%F(%L) -%m%n
    log4j.appender.FILE=org.apache.log4j.RollingFileAppender
    log4j.appender.FILE.maxBackupIndex=100
    ##log4j.appender.FILE=org.apache.log4j.DailyRollingFileAppender 
    log4j.appender.FILE.Append=true
    log4j.appender.FILE.File=c:/error1.log
    log4j.appender.FILE.Threshold=INFO
    log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
    log4j.appender.FILE.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} [%5p] - %c -%F(%L) -%m%n
    log4j.appender.FILE.MaxFileSize=1MB

4、实体类 User.java

package cn.sz.entity;
    
    import java.io.Serializable;
    import java.util.Date;
    import java.util.List;
    import java.util.Map;
    import java.util.Set;
    
    public class User implements Serializable {
    	// 适应数值形式的主键值
    	private Integer uid;
    	private String uname;
    	private Date udate;
    
    	private String content;
    	// 使用字节数组存储图片
    	private byte[] photo;
    
    	// 集合类型的属性
    	// Set集合
    	private Set<String> setAddress;
    	// List集合
    	private List<String> listAddress;
    	// 对应映射文件bag
    	private List<String> bagListAddress;
    	// Map集合
    	private Map<String, String> mapAddress;
    	// 数组属性
    	private String[] arrayAddress;
    
    	public User() {
    
    	}
    
    	public Set<String> getSetAddress() {
    		return setAddress;
    	}
    
    	public void setSetAddress(Set<String> setAddress) {
    		this.setAddress = setAddress;
    	}
    
    	public List<String> getListAddress() {
    		return listAddress;
    	}
    
    	public void setListAddress(List<String> listAddress) {
    		this.listAddress = listAddress;
    	}
    
    	public List<String> getBagListAddress() {
    		return bagListAddress;
    	}
    
    	public void setBagListAddress(List<String> bagListAddress) {
    		this.bagListAddress = bagListAddress;
    	}
    
    	public Map<String, String> getMapAddress() {
    		return mapAddress;
    	}
    
    	public void setMapAddress(Map<String, String> mapAddress) {
    		this.mapAddress = mapAddress;
    	}
    
    	public String[] getArrayAddress() {
    		return arrayAddress;
    	}
    
    	public void setArrayAddress(String[] arrayAddress) {
    		this.arrayAddress = arrayAddress;
    	}
    
    	public String getContent() {
    		return content;
    	}
    
    	public void setContent(String content) {
    		this.content = content;
    	}
    
    	public byte[] getPhoto() {
    		return photo;
    	}
    
    	public void setPhoto(byte[] photo) {
    		this.photo = photo;
    	}
    
    	public Date getUdate() {
    		return udate;
    	}
    
    	public void setUdate(Date udate) {
    		this.udate = udate;
    	}
    
    	public Integer getUid() {
    		return uid;
    	}
    
    	public void setUid(Integer uid) {
    		this.uid = uid;
    	}
    
    	public String getUname() {
    		return uname;
    	}
    
    	public void setUname(String uname) {
    		this.uname = uname;
    	}
    
    }

5、User实体映射文件User.hbm.xml

<?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 package="cn.sz.entity">
    	
    	<class table="q_user" name="User">
    		
    		<id name="uid">
    			
    			<generator class="native"></generator>
    		</id>
    		
    		
    		<property name="uname" length="30"></property>
    
    		<property name="udate" type="date"></property>
    		<property name="content" type="text" length="10000"></property>
    		<property name="photo" type="byte[]" length="1024000"></property>
    
    		
    		<set name="setAddress" table="q_set">
    			
    			<key column="userid"></key>
    			<element column="address" type="string"></element>
    		</set>
    
    		
    		<list name="listAddress" table="q_list">
    			<key column="userid"></key>
    			<list-index column="index_"></list-index>
    			<element column="address" type="string"></element>
    		</list>
    
    		
    		<bag name="bagListAddress" table="q_bag">
    			<key column="userid"></key>
    			<element column="address" type="string"></element>
    		</bag>
    
    		
    		<array name="arrayAddress" table="q_arr">
    			<key column="userid"></key>
    			<index column="index_"></index>
    			<element column="address" type="string"></element>
    		</array>
    
    		
    		<map name="mapAddress" table="q_map">
    			<key column="userid"></key>
    			
    			<map-key column="key_" type="string"></map-key>
    			<element column="address" type="string"></element>
    		</map>
    	</class>
    </hibernate-mapping>

6、测试类

package cn.sz.test;
    
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.util.ArrayList;
    import java.util.Date;
    import java.util.HashMap;
    import java.util.HashSet;
    import java.util.List;
    import java.util.Map;
    import java.util.Map.Entry;
    import java.util.Set;
    
    import org.hibernate.Session;
    import org.junit.Test;
    
    import cn.sz.entity.User;
    import cn.sz.utils.HibernateUtil;
    
    public class UserTest {
    	@Test
    	public void testSave() throws IOException {
    		Session session = HibernateUtil.getSession();
    		session.beginTransaction();
    		// 创建一个用户
    		User u = new User();
    		u.setUname("张三");
    		u.setContent("张三的个人简介");
    		u.setUdate(new Date());
    		// 读取图片
    		InputStream is = new FileInputStream(new File("C:\\Users\\Administrator\\Desktop\\test.jpg"));
    		byte[] photo = new byte[is.available()];
    		is.read(photo);
    		u.setPhoto(photo);
    
    		// 创建Map集合
    		Map<String, String> map = new HashMap<>();
    		map.put("a1", "北京");
    		map.put("a2", "上海");
    		// 将map集合绑定到用户
    		u.setMapAddress(map);
    
    		// 创建List集合
    		List<String> list = new ArrayList<>();
    		list.add("南京");
    		list.add("昆明");
    		// 将List集合绑定到用户
    		u.setListAddress(list);
    
    		// 测试List集合和Set的结合体bag
    		List<String> list2 = new ArrayList<>();
    		list2.add("南京");
    		list2.add("昆明");
    		// 将List集合绑定到用户
    		u.setBagListAddress(list2);
    
    		// 创建Set集合
    		Set<String> set = new HashSet<>();
    		set.add("西藏");
    		set.add("深圳");
    		// 将set集合绑定到用户
    		u.setSetAddress(set);
    
    		// 创建数组
    		String[] arr = new String[2];
    		arr[0] = "龙华";
    		arr[1] = "澳门";
    		// 将数组绑定到用户
    		u.setArrayAddress(arr);
    
    		session.save(u);
    		session.getTransaction().commit();
    		is.close();
    		session.close();
    	}
    
    	@Test
    	public void testQuery() throws IOException {
    		Session session = HibernateUtil.getSession();
    		session.beginTransaction();
    		// 查询id为1的用户姓名
    		User user = session.get(User.class, 1);
    
    		System.out.println(user.getUname());
    
    		// set集合查询
    		Set<String> set = user.getSetAddress();
    		for (String string : set) {
    			System.out.println(string);
    		}
    		// list集合查询
    		List<String> listAddress = user.getListAddress();
    		for (String string : listAddress) {
    			System.out.println(string);
    		}
    		// map集合查询
    		Map<String, String> mapAddress = user.getMapAddress();
    		Set<String> keySet = mapAddress.keySet();
    		for (String string : keySet) {
    			System.out.println(mapAddress.get(string));
    		}
    
    		// 数组查询
    		String[] arrayAddress = user.getArrayAddress();
    		for (String string : arrayAddress) {
    			System.out.println(string);
    		}
    		// bag
    		List<String> bagListAddress = user.getBagListAddress();
    		for (String string : bagListAddress) {
    			System.out.println(string);
    		}
    
    		// 将图片写出去
    		OutputStream os = new FileOutputStream(new File("C:\\Users\\Administrator\\Desktop\\测试.jpg"));
    		byte[] photo = user.getPhoto();
    		os.write(photo);
    
    		os.close();
    		session.getTransaction().commit();
    		session.close();
    	}
    }

[Center]: /images/20220606/c09f70514e8d437ea48ee0d8b48d8dcf.png
[Center 1]: /images/20220606/5e70341d433d4453b13bbab1219e3160.png
[http_blog.csdn.net_benxiaohai888_article_details_78231911]: http://blog.csdn.net/benxiaohai888/article/details/78231911