Hibernate的多对一操作：
例子参考引用：
http://www.tutorialspoint.com/hibernate/hibernate_many_to_one_mapping.htm
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> <!-- Database connection settings -->
<property name="connection.driver_class">com.mysql.jdbc.Driver</property>
<property name="connection.url">jdbc:mysql://127.0.0.1/testdb</property>
<property name="connection.username">root</property>
<property name="connection.password"></property> <!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property> <!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.MySQL5Dialect</property> <!-- Enable Hibernate's automatic session context management -->
<property name="current_session_context_class">thread</property> <!-- Disable the second-level cache -->
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property> <!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property> <!-- Drop and re-create the database schema on startup -->
<property name="hbm2ddl.auto">update</property> <mapping resource="com/my/hbm/User.hbm.xml"/>
<mapping resource="com/my/hbm/UserAccount.hbm.xml"/> </session-factory> </hibernate-configuration>
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> <class name="com.my.bean.User" table="user">
<id name="id" type="int">
<column name="id" />
<generator class="native" />
</id>
<property name="name" type="java.lang.String" length="50">
<column name="name" not-null="true" length="50" />
</property>
<property name="age" type="int">
<column name="age" />
</property>
<property name="password" type="java.lang.String" length="50">
<column name="password" length="50" />
</property>
<property name="email" type="java.lang.String" length="100">
<column name="email" length="100" />
</property>
<property name="createtime" type="java.util.Date">
<column name="createtime" />
</property>
</class> </hibernate-mapping>
UserAccount.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> <class name="com.my.bean.UserAccount" table="user_account">
<id name="id" type="int">
<column name="id" />
<generator class="native" />
</id>
<many-to-one name="user" column="user_id" class="com.my.bean.User" not-null="true"></many-to-one>
<property name="account" type="java.lang.String" length="50">
<column name="account" not-null="true" length="50" />
</property>
</class> </hibernate-mapping>
Java Bean: User.java
package com.my.bean;
import java.util.Date;
public class User {
private int id;
private String name;
private int age;
private String password;
private String email;
private Date createtime;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
public int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public Date getCreatetime() {
return createtime;
}
public void setCreatetime(Date createtime) {
this.createtime = createtime;
}
}Java Bean: UserAccount.java
package com.my.bean;
public class UserAccount {
private int id;
private String account;
private User user;
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getAccount() {
return account;
}
public void setAccount(String account) {
this.account = account;
}
public User getUser() {
return user;
}
public void setUser(User user) {
this.user = user;
}
}HibernateUtil.java
package com.my.dao.util; import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration; public class HibernateUtil { private static final SessionFactory sessionFactory = buildSessionFactory(); private static SessionFactory buildSessionFactory() {
try {
// Create the SessionFactory from hibernate.cfg.xml
Configuration configuration = new Configuration();
return configuration.configure().buildSessionFactory(
new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build());
} catch (Throwable ex) {
// Make sure you log the exception, as it might be swallowed
System.err.println("Initial SessionFactory creation failed." + ex);
throw new ExceptionInInitializerError(ex);
}
} public static SessionFactory getSessionFactory() {
return sessionFactory;
} }
测试：
package com.my.init; import java.util.Date;
import java.util.List; import org.hibernate.HibernateException;
import org.hibernate.Query;
import org.hibernate.Session; import com.my.bean.User;
import com.my.bean.UserAccount;
import com.my.dao.util.HibernateUtil; public class Test { public static void main(String[] args) {
Test t = new Test(); // Add new user
User user = t
.addUser("robin", "abcd1234", "robin@88db.com", new Date());
System.out.println(user.getId()); // Get user list
List<User> users = t.listUser();
for (User item : users) {
System.out.println("User name: " + item.getName());
} // Add UserAccount
UserAccount ua = t.addUserAccount("robinzhang", user);
System.out.println("Add UserAccount: " + ua.getId()); // Update UserAccount
UserAccount ua_u = t.updateUserAccount(ua.getId(), "robin_zhang");
System.out.println("Update UserAccount: " + ua_u.getAccount()); // Get User Account List
List<UserAccount> uas = t.listUserAccount();
for (UserAccount item : uas) {
System.out.println("UserAccount: " + item.getAccount());
System.out.println("UserID: " + item.getUser().getId());
} // Delete UserAccount
boolean result = t.deleteUserAccount(1);
System.out.println("Delete UserAccount: " + result); // Delete User
result = t.deleteUser(user);
System.out.println("Delete User: " + result);
} /**
* List Users
*/
@SuppressWarnings("unchecked")
public List<User> listUser() {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); List<User> users = null;
try {
// Select action
String hqlSelect = "from User where name like :name";
Query query = session.createQuery(hqlSelect);
query.setParameter("name", "%ro%");
users = query.list();
session.getTransaction().commit();
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
}
return users;
} /**
* Add new user
*
* @param name
* User name
* @param password
* User password
* @param email
* User email
* @param createtime
* User create time
* @return User object
*/
public User addUser(String name, String password, String email,
Date createtime) {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); User u = new User();
try {
u.setName(name);
u.setPassword(password);
u.setCreatetime(createtime);
u.setEmail(email);
u.setAge(18);
// Get new user id
Integer userid = (Integer) session.save(u);
session.getTransaction().commit();
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
} return u;
} /**
* Get UserAccount Object
*
* @param account
* account name
* @param user
* User ID
* @return UserAccount object
*/
public UserAccount addUserAccount(String account, User user) {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); UserAccount ua = null;
try {
ua = new UserAccount();
ua.setAccount(account);
ua.setUser(user);
session.save(ua);
session.getTransaction().commit();
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
} return ua;
} /**
* Get User Account List
*
* @return
*/
@SuppressWarnings("unchecked")
public List<UserAccount> listUserAccount() {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); List<UserAccount> uas = null;
try {
String hqlSelect = "from UserAccount where account like :account";
Query query = session.createQuery(hqlSelect);
query.setParameter("account", "%ro%");
uas = query.list();
session.getTransaction().commit();
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
} return uas;
} /**
* Update User Account
*
* @param id
* @param account
*/
public UserAccount updateUserAccount(Integer id, String account) {
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); UserAccount ua = null;
try {
ua = (UserAccount) session.get(UserAccount.class, id);
ua.setAccount(account);
session.update(ua);
session.getTransaction().commit();
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
} return ua;
} /**
* Delete UserAccount
*
* @param id
* @return true/false
*/
public boolean deleteUserAccount(Integer id) {
boolean result = false;
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); try {
UserAccount ua = (UserAccount) session.get(UserAccount.class, id);
session.delete(ua);
session.getTransaction().commit();
result = true;
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
} return result;
} /**
* Delete User
*
* @param user
* @return
*/
public boolean deleteUser(User user) {
boolean result = false;
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction(); try {
session.delete(user);
session.getTransaction().commit();
result = true;
} catch (HibernateException e) {
if (session.getTransaction() != null)
session.getTransaction().rollback();
e.printStackTrace();
} finally {
session.close();
} return result;
} }
使用Hibernate会自动建库。