hibernate入门篇之新增特性.txt

Hibernate使用说明书

作者：smallduzi(杜恒飞)

版权声明：本文严禁转载，如有转载请求，请和作者联系

版本：hibernate-2.1final。

eclipse 2.1.2。

jsdk-1.4.2

所有文件存放在：com.javamodel.hibernate目录下

hibernate在连接数据库方面有两种方式：

1。使用hibernate.properties文件，我下面采用的就是这种方式。这种方式比较直观，也符合一些老程序员的思维模式。

2。使用hibernate.cfg.xml文件，这是hibernate默认的文件，在这里可以描述mapping文件，我想这就是最大的好处吧。

好，让我们开始吧！

Example.java

package com.javamodel.hibernate;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;
import net.sf.hibernate.HibernateException;
import net.sf.hibernate.MappingException;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.Transaction;
import net.sf.hibernate.cfg.Configuration;

public class Example{
    
    private static SessionFactory _sessions = null;
    private static Properties pops = new Properties();
    //启动后，一次加载。
    static{
        try {
                //这里根据个人的喜好，在这里要是着这样的话："/hibernate.properties"，
                //就可以把hibernate.properties放到src目录下和com平级，在tomcate中放在web应用程序的web-inf/class目录下了。
            InputStream stream = Example.class.getResourceAsStream("hibernate.properties");
            try {
                pops.load(stream);
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            Configuration cfg = new Configuration();
            //比较麻烦的地方，class需要一个一个的加载。也就是增加一个表和对应的类，那各类要在这里注册一下。
            cfg.addClass(Person.class);
            cfg.setProperties(pops);
            _sessions = cfg.buildSessionFactory();
        } catch (MappingException e) {
           e.printStackTrace();
        } catch (HibernateException e) {
           e.printStackTrace();
        }
    
    }
    
    public static void main(String[] args) throws HibernateException {
        
        Person person = new Person();
        person.setName("smallduzi");
        person.setEmail("[e-mail]");
        
        Session session = _sessions.openSession();
        
        Transaction tx = null;
        try{
            tx = session.beginTransaction();
            session.save(person);
            tx.commit();        
        }catch(HibernateException he){
            if(tx != null) tx.rollback();
            throw he;
        }
        finally{
            session.close();
        }
        
    }
    
}

Person.java

package com.javamodel.hibernate;

public class Person {
    
    private String id = null;
    private String name = null;
    private String email = null;    
    
    public Person(){}

    /**
     * @return
     */
    public String getEmail() {
        return email;
    }

    /**
     * @return
     */
    public String getId() {
        return id;
    }

    /**
     * @return
     */
    public String getName() {
        return name;
    }

    /**
     * @param string
     */
    public void setEmail(String string) {
        email = string;
    }

    /**
     * @param string
     */
    public void setId(String string) {
        id = string;
    }

    /**
     * @param string
     */
    public void setName(String string) {
        name = string;
    }

}

Person.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
<hibernate-mapping>
    <class name="com.javamodel.hibernate.Person" table="person">
        <id name="id">
            <column name="id" length="40"/>
            <generator class="uuid.hex"/>
        </id>
        <property name="name" column="name" />
        <property name="email" column="email" />
    </class>
</hibernate-mapping>

这里我用的是oracle数据库，如果你使用的是其他数据库，可参照hibernate.properties中其他的数据库连接说明。

hibernate.properties

## Oracle

hibernate.dialect net.sf.hibernate.dialect.OracleDialect
hibernate.connection.driver_class oracle.jdbc.driver.OracleDriver
hibernate.connection.username XXX
hibernate.connection.password XXX
#hibernate.connection.url jdbc:oracle:thin:@192.168.0.28:1521:orcl
hibernate.connection.url jdbc:oracle:oci8:@XXX

我没有对他进行进一步的封装。那样初学者可能不理解。对session的封装，可以参照hibernate文档的HibernateUtil.java这个类（没记错的话）。

注意：在工程里要引用hibernate的jar。参照hibernate的文档中有说需要的必须的jar。

作者：smallduzi(杜恒飞)

版权声明：本文严禁转载，如有转载请求，请和作者联系

接上一篇文章Hibernate入门篇之新增特性。我们继续进行！

Author.java

package com.javamodel.hibernate;

public class Author{
    
    private String id ;
    private String alias = null;
    private Person person = null;
    
    /**
     * @return
     */
    public String getAlias() {
        return alias;
    }

    /**
     * @return
     */
    public Person getPerson() {
        return person;
    }

    /**
     * @param string
     */
    public void setAlias(String string) {
        alias = string;
    }
    /**
     * @param person
     */
    public void setPerson(Person person) {
        this.person = person;
    }
    /**
     * @return
     */
    public String getId() {
        return id;
    }
    /**
     * @param i
     */
    public void setId(String i) {
        id = i;
    }

}

author.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
<hibernate-mapping>
    <class name="com.javamodel.hibernate.Author" table="author" > 
        <id name="id" column="id">
            <!-- 这里我把author作为主表，外键的描述也可以在Person.hbm.xml中表述，也是可以的-->
            <generator class="foreign">
              <param name="property">person</param>
            </generator>
        </id>
        <property name="alias" column="alias" />
        <one-to-one name="person" class="com.javamodel.hibernate.Person" cascade="all" constrained="true" />
    </class>
</hibernate-mapping>

Example.java

package com.javamodel.hibernate;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.MappingException;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.Transaction;
import net.sf.hibernate.cfg.Configuration;

public class Example{
    
    private static SessionFactory _sessions = null;
    private static Properties pops = new Properties();
    
    static{
        try {
            InputStream stream = Example.class.getResourceAsStream("hibernate.properties");
            try {
                pops.load(stream);
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            
            Configuration cfg = new Configuration();
            cfg.addClass(Person.class);
            cfg.addClass(Author.class);
            cfg.setProperties(pops);
            _sessions = cfg.buildSessionFactory();
            
        } catch (MappingException e) {
           e.printStackTrace();
        } catch (HibernateException e) {
           e.printStackTrace();
        }
    
    }
    
    public static void main(String[] args) throws HibernateException {
        
        Person person = new Person();
        
        person.setName("HengfeiDo");
        person.setEmail("[e-mail]");
        
        Author author = new Author();

        author.setAlias("smallduzi");
        author.setPerson(person);

        Session session = _sessions.openSession();
        
        Transaction tx = null;
        try{
            tx = session.beginTransaction();
            session.save(author);
            
            tx.commit();
            System.out.println("over");
        }catch(HibernateException he){
            if(tx != null) tx.rollback();
            throw he;
        }
        finally{
            session.close();
        }
        
    }
    
}

如果大家有更好的实现方式可拿出来讨论一下！

我将在下一篇文章介绍one-to-many。

参与讨论

hibernate入门篇之新增特性_3：one-to-many
作者：smallduzi(杜恒飞)

版权声明：本文严禁转载，如有转载请求，请和作者联系

接上一篇文章hibernate入门篇之新增特性_2：one-to-one。我们再继续进行！（为什么要说再呢？）

one to many时，两端都需要描述。

Publication.java

package com.javamodel.hibernate;
public class Publication {
    
    private String id = null;
    private String bookName = null;
    private String dataTime = null;
    private String authorId = null;
    private Author author = null;
    
    public Publication(){}
    
    /**
     * @return
     */
    public String getBookName() {
        return bookName;
    }

    /**
     * @return
     */
    public String getDataTime() {
        return dataTime;
    }

    /**
     * @return
     */
    public String getId() {
        return id;
    }

    /**
     * @param string
     */
    public void setBookName(String string) {
        bookName = string;
    }

    /**
     * @param string
     */
    public void setDataTime(String string) {
        dataTime = string;
    }

    /**
     * @param string
     */
    public void setId(String string) {
        id = string;
    }

    /**
     * @return
     */
    public String getAuthorId() {
        return authorId;
    }

    /**
     * @param string
     */
    public void setAuthorId(String string) {
        authorId = string;
    }

    /**
     * @return
     */
    public Author getAuthor() {
        return author;
    }

    /**
     * @param author
     */
    public void setAuthor(Author author) {
        this.author = author;
    }

}

Publication.hbm.xml

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping SYSTEM "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd" >
<hibernate-mapping>
    <class name="com.javamodel.hibernate.Publication" table="publication">
        <id name="id" column="id">
            <generator class="uuid.hex"/>
        </id>
        <property name="bookName" column="bookname" />
        <property name="dataTime" column="datatime" />
        <!--多的这端也需要一个简单的many-to-one的描述-->
        <many-to-one name="author" column="authorid" />
    </class>
</hibernate-mapping>

Author.java加上

private Set publications = new HashSet();//add get,set

author.hbm.xml加上

<!--
     这里是主的这端，你可以使用set,list,bag等，参照说明文档，inverse="true",默认为false。这个地方
    在描述这两个对应的mapping文件的时候，必须要有一端为:true。yehs220也多次提到过。
-->
        <set name="publications" lazy="true" inverse="true" cascade="all" >
          <key column="authorid"/> 
          <one-to-many class="com.javamodel.hibernate.Publication" />
        </set>

Example.java

package com.javamodel.hibernate;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

import net.sf.hibernate.HibernateException;
import net.sf.hibernate.MappingException;
import net.sf.hibernate.Session;
import net.sf.hibernate.SessionFactory;
import net.sf.hibernate.Transaction;
import net.sf.hibernate.cfg.Configuration;

public class Example{
    
    private static SessionFactory _sessions = null;
    private static Properties pops = new Properties();
    
    static{
        try {
            InputStream stream = Example.class.getResourceAsStream("hibernate.properties");
            try {
                pops.load(stream);
            } catch (IOException e1) {
                e1.printStackTrace();
            }
            
            Configuration cfg = new Configuration();
            cfg.addClass(Person.class);
            cfg.addClass(Author.class);
            cfg.addClass(Publication.class);
            cfg.setProperties(pops);
            _sessions = cfg.buildSessionFactory();
            
        } catch (MappingException e) {
           e.printStackTrace();
        } catch (HibernateException e) {
           e.printStackTrace();
        }
    
    }
    
    public static void main(String[] args) throws HibernateException {
        
        Person person = new Person();
        
        person.setName("HengfeiDo");
        person.setEmail("[e-mail]");
        
        Publication publication1 = new Publication();
        publication1.setBookName("AAA");
        publication1.setDataTime("20031224");
        Publication publication2 = new Publication();
        publication2.setBookName("BBB");
        publication2.setDataTime("20031225");
        
        Author author = new Author();

        author.setAlias("smallduzi");
        author.setPerson(person);
        author.getPublications().add(publication1);
        author.getPublications().add(publication2);
        
        publication1.setAuthor(author);
        publication2.setAuthor(author);

        Session session = _sessions.openSession();
        
        Transaction tx = null;
        try{
            tx = session.beginTransaction();
            session.save(author);
            
            tx.commit();
            System.out.println("over");
        }catch(HibernateException he){
            if(tx != null) tx.rollback();
            throw he;
        }
        finally{
            session.close();
        }
        
    }
    
}

下一篇，我们介绍many-to-many