接下来我们开始介绍Hibernate的数据类型，因为我们现在暂时只关注Hibernate这块，因此我们这次只建立一个Java Project，命名为hibernate2。
加入hibernate JAR包：
选择hibernate2项目，点击MyEclipse->Add Hibernate Capabilities, Hibernate Specification与风中页老师的相同，为Hibernate3.2，点击next，继续next，去掉Specify database connection details前面的√接着next，去掉Create SessionFactory class？前面的√点击Finish。
把上一个hibernate项目的hibernate.cfg.xml文件拷贝过来，覆盖掉当前src下面的hibernate.cfg.xml文件，修改mapping信息：
<?xml version=‘1.0‘ encoding=‘UTF-8‘?>
<!DOCTYPE hibernate-configuration PUBLIC
"-//Hibernate/Hibernate Configuration DTD 3.0//EN"
"http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<!-- Generated by MyEclipse Hibernate Tools. -->
<hibernate-configuration>
<session-factory>
<property name="show_sql">true</property> <!-- 属性之间没有上下关系，放在哪里都行 -->
<property name="connection.url">jdbc:mysql://localhost:3306/myhibernate</property>
<property name="connection.username">root</property>
<property name="connection.password">root</property>
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="dialect">org.hibernate.dialect.MySQLDialect</property>
<mapping resource="Customers.hbm.xml"/> <!-- 将主配置文件包含对象-关系映射文件，之所以映射是因为hibernate启动时只会加载主配置文件 -->
</session-factory>
</hibernate-configuration>
添加MySql驱动，从hibernate项目拷贝mysql-connector-java-5.1.34-bin.jar到hibernate根目录下。
创建表：（bigint即long类型；bit即boolean类型；timestamp也是一个日期类型的，比date精度更高，可以精确到毫秒；blob即二进制大型物件）
mysql> create table CUSTOMERS(
-> ID bigint not null primary key,
-> NAME varchar(15) not null,
-> EMAIL varchar(128) not null,
-> PASSWORD varchar(8) not null,
-> PHONE int,
-> ADDRESS varchar(255),
-> SEX char(1),
-> IS_MARRIED bit,
-> DESCRIPTION text,
-> IMAGE blob,
-> BIRTHDAY date,
-> REGISTERED_TIME timestamp
-> );
新建com.test.bean包，在该包下面新建一个类Customer.java:
package com.test.bean;
import java.sql.Date;
import java.sql.Timestamp;
public class Customer
{
private Long id;
private String name;
private String email;
private String password;
private int phone; // or Integer
private String address;
private char sex;
private boolean married;
private String description;
private byte[] image;
private Date birthday;
private Timestamp registeredTime;
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 String getEmail()
{
return email;
}
public void setEmail(String email)
{
this.email = email;
}
public String getPassword()
{
return password;
}
public void setPassword(String password)
{
this.password = password;
}
public int getPhone()
{
return phone;
}
public void setPhone(int phone)
{
this.phone = phone;
}
public String getAddress()
{
return address;
}
public void setAddress(String address)
{
this.address = address;
}
public char getSex()
{
return sex;
}
public void setSex(char sex)
{
this.sex = sex;
}
public boolean isMarried()
{
return married;
}
public void setMarried(boolean married)
{
this.married = married;
}
public String getDescription()
{
return description;
}
public void setDescription(String description)
{
this.description = description;
}
public byte[] getImage()
{
return image;
}
public void setImage(byte[] image)
{
this.image = image;
}
public Date getBirthday()
{
return birthday;
}
public void setBirthday(Date birthday)
{
this.birthday = birthday;
}
public Timestamp getRegisteredTime()
{
return registeredTime;
}
public void setRegisteredTime(Timestamp registeredTime)
{
this.registeredTime = registeredTime;
}
}
在src下面新建一个Customers.hbm.xml：
<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd"> <hibernate-mapping> <class name="com.test.bean.Customer" table="customers"> <!-- 将类与表相关联，使得类中的属性和表中的字段关联起来 --> <id name="id" column="id" type="long"> <!-- 类中id属性和映射到表中的id字段，类型为int/integer皆可 --> <generator class="increment"> <!-- 主键id的生成方式为自增 --> </generator> </id> <property name="name" column="name" type="string" not-null="true"></property> <!-- 如果不写字段名，则默认与类中的属性名相同 ;hibernate层和数据库层都可以对非空进行检查--> <property name="email" column="email" type="string" not-null="true"></property> <property name="password" column="password" type="string" not-null="true"></property> <property name="phone" column="phone" type="int"></property> <property name="address" column="address" type="string" ></property> <property name="sex" column="sex" type="character" ></property> <property name="married" column="is_married" type="boolean" ></property> <property name="description" column="description" type="text"></property> <property name="image" column="image" type="binary" ></property> <property name="birthday" column="birthday" type="date" ></property> <property name="registeredTime" column="registered_time" type="timestamp"></property> </class> </hibernate-mapping>
在com.test.bean包下面，创建测试类HibernateTest.java同时放置一个photo.gif文件：
package com.test.bean;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.io.PrintStream;
import java.sql.Date;
import java.util.Iterator;
import java.util.List;
import org.hibernate.Query;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.Transaction;
import org.hibernate.cfg.Configuration;
public class HibernateTest
{
public static SessionFactory sessionFactory;
static
{
try
{
Configuration config = new Configuration().configure();
sessionFactory = config.buildSessionFactory();
}
catch (Exception e)
{
e.printStackTrace();
}
}
public void findAllCustomers(PrintStream out) throws Exception
{
// Ask for a session using the JDBC information we‘ve configured
Session session = sessionFactory.openSession();
Transaction tx = null;
try
{
tx = session.beginTransaction();
List customers = session.createQuery("from Customer as c order by c.name asc").list();
for (Iterator it = customers.iterator(); it.hasNext();)
{
printCustomer(out, (Customer) it.next());
}
// We‘re done; make our changes permanent
tx.commit();
}
catch (Exception e)
{
if (tx != null)
{
// Something went wrong; discard all partial changes
tx.rollback();
}
throw e;
}
finally
{
// No matter what, close the session
session.close();
}
}
public static void saveCustomer(Customer customer) throws Exception
{
// Ask for a session using the JDBC information we‘ve configured
Session session = sessionFactory.openSession();
Transaction tx = null;
try
{
tx = session.beginTransaction();
session.save(customer);
// We‘re done; make our changes permanent
tx.commit();
}
catch (Exception e)
{
if (tx != null)
{
// Something went wrong; discard all partial changes
tx.rollback();
}
throw e;
}
finally
{
// No matter what, close the session
session.close();
}
}
public void loadAndUpdateCustomer(Long customer_id, String address)
throws Exception
{
// Ask for a session using the JDBC information we‘ve configured
Session session = sessionFactory.openSession();
Transaction tx = null;
try
{
tx = session.beginTransaction();
Customer c = (Customer) session.load(Customer.class, customer_id);
c.setAddress(address);
// We‘re done; make our changes permanent
tx.commit();
}
catch (Exception e)
{
if (tx != null)
{
// Something went wrong; discard all partial changes
tx.rollback();
}
throw e;
}
finally
{
// No matter what, close the session
session.close();
}
}
public void deleteAllCustomers() throws Exception
{
// Ask for a session using the JDBC information we‘ve configured
Session session = sessionFactory.openSession();
Transaction tx = null;
try
{
tx = session.beginTransaction();
Query query = session.createQuery("from Customer");
List list = query.list();
for (Iterator i = list.iterator(); i.hasNext();)
{
session.delete((Customer) i.next());
}
tx.commit();
}
catch (Exception e)
{
if (tx != null)
{
// Something went wrong; discard all partial changes
tx.rollback();
}
throw e;
}
finally
{
// No matter what, close the session
session.close();
}
}
private void printCustomer(PrintStream out, Customer customer)
throws Exception
{
byte[] buffer = customer.getImage();
OutputStream fout = new FileOutputStream("photo_copy.gif");
fout.write(buffer);
fout.close();
out.println("------以下是" + customer.getName() + "的个人信息------");
out.println("ID: " + customer.getId());
out.println("口令: " + customer.getPassword());
out.println("E-Mail: " + customer.getEmail());
out.println("电话: " + customer.getPhone());
out.println("地址: " + customer.getAddress());
String sex = customer.getSex() == ‘M‘ ? "男" : "女";
out.println("性别: " + sex);
String marriedStatus = customer.isMarried() ? "已婚" : "未婚";
out.println("婚姻状况: " + marriedStatus);
out.println("生日: " + customer.getBirthday());
out.println("注册时间: " + customer.getRegisteredTime());
out.println("自我介绍: " + customer.getDescription());
}
public void test(PrintStream out) throws Exception
{
Customer customer = new Customer();
customer.setName("zhangsan");
customer.setEmail("[email protected]");
customer.setPassword("1234");
customer.setPhone(1381234);
customer.setAddress("Shanghai");
customer.setSex(‘M‘);
customer.setDescription("I am very honest.");
InputStream in = this.getClass().getResourceAsStream("photo.gif");
byte[] buffer = new byte[in.available()];
in.read(buffer);
customer.setImage(buffer);
customer.setBirthday(Date.valueOf("1980-05-06"));
saveCustomer(customer);
findAllCustomers(out);
loadAndUpdateCustomer(customer.getId(), "Tianjin");
findAllCustomers(out);
deleteAllCustomers();
}
public static void main(String args[]) throws Exception
{
new HibernateTest().test(System.out);
sessionFactory.close();
}
}
通过给一下几行代码添加注释的方式进行测试：
saveCustomer(customer); findAllCustomers(out); loadAndUpdateCustomer(customer.getId(), "Tianjin"); findAllCustomers(out); deleteAllCustomers();
运行后在hibernate2根目录下面会生成一个photo_copy.gif图形文件。
上面的例子比较简单，下面我们看一个复杂的：表与表之间存在关联关系，类与类之间存在关联关系：
时间： 2024-11-10 01:10:17