在IntelliJ IDEA中配置MySQL Database.
Database是我们事先建立的数据库，对应我们的某一个项目.
添加Hibernate框架.
项目上右键->Add Framework Support.
Package是放置我们的实体类，一般是xx.xx.model就可以了.
生成的实体类已经包含了映射信息，所以不需要x.hbm.xml文件了.
@Entity
@Table(name = "users", schema = "mydb", catalog = "")
public class UsersEntity {
private int id;
private String name;
private Byte age;
@Id
@Column(name = "id", nullable = false)
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
@Basic
@Column(name = "name", nullable = true, length = 100)
public String getName() {
return name;
}
public void setName(String name) {
this.name = name;
}
@Basic
@Column(name = "age", nullable = true)
public Byte getAge() {
return age;
}
public void setAge(Byte age) {
this.age = age;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
UsersEntity that = (UsersEntity) o;
if (id != that.id) return false;
if (name != null ? !name.equals(that.name) : that.name != null) return false;
if (age != null ? !age.equals(that.age) : that.age != null) return false;
return true;
}
@Override
public int hashCode() {
int result = id;
result = 31 * result + (name != null ? name.hashCode() : 0);
result = 31 * result + (age != null ? age.hashCode() : 0);
return result;
}
}
那么再来看看Hiebrnate的配置文件，注意，该配置文件不在正确的路径上。在WEB-INF下建立文件夹classes,放进去.
没有Driver的jar包.
拷贝到lib目录中，还没完，为什么呢？没有添加到Build Path中.看！前面都没有三角标记.
跟别人不一样嘛.
右键项目->Open Model Settings->Libraries.
要注意关注Problems.
系统为我们生成了数据库连接的代码
public class Main {
private static final SessionFactory ourSessionFactory;
private static final ServiceRegistry serviceRegistry;
static {
try {
Configuration configuration = new Configuration();
configuration.configure();
serviceRegistry = new ServiceRegistryBuilder().applySettings(configuration.getProperties()).buildServiceRegistry();
ourSessionFactory = configuration.buildSessionFactory(serviceRegistry);
} catch (Throwable ex) {
throw new ExceptionInInitializerError(ex);
}
}
public static Session getSession() throws HibernateException {
return ourSessionFactory.openSession();
}
public static void main(final String[] args) throws Exception {
final Session session = getSession();
try {
System.out.println("querying all the managed entities...");
final Map metadataMap = session.getSessionFactory().getAllClassMetadata();
for (Object key : metadataMap.keySet()) {
final ClassMetadata classMetadata = (ClassMetadata) metadataMap.get(key);
final String entityName = classMetadata.getEntityName();
final Query query = session.createQuery("from " + entityName);
System.out.println("executing: " + query.getQueryString());
for (Object o : query.list()) {
System.out.println(" " + o);
}
}
} finally {
session.close();
}
}
}
新建目录db,将Main类改名成DbConnections.
获取数据库中的数据
@Controller
@RequestMapping("/users")
public class UserController {
@RequestMapping(value = "/list.do", method = RequestMethod.GET)
public String listUsers(ModelMap map) {
Session session = DbConnections.getSession();
List<UsersEntity> list = session.createCriteria(UsersEntity.class).list();
map.addAttribute("users", list);
session.close();
return "users";
}
}
doc + Alt + /:生成html模板，Alt + /需要自己配置.
<%@ page import="com.winner.db.entities.UsersEntity" %>
<%@ page import="java.util.List" %>
<%@ page pageEncoding="utf-8" %>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<ol>
<%for (UsersEntity e:(List<UsersEntity>)request.getAttribute("users")){%>
<li>名字：<%out.println(e.getName());%>，年龄：<%out.println(e.getAge());%></li>
<%}%>
</ol>
</body>
</html>
向数据库中添加用户：
@Controller
@RequestMapping("/users")
public class UserController {
@RequestMapping(value = "/list.do", method = RequestMethod.GET)
public String listUsers(ModelMap map) {
Session session = DbConnections.getSession();
List<UsersEntity> list = session.createCriteria(UsersEntity.class).addOrder(Order.desc("id")).list();
map.addAttribute("users", list);
session.close();
return "users";
}
@RequestMapping(value = "/add.do", method = RequestMethod.GET)
public String addUser() {
return "add_user";
}
@RequestMapping(value = "/result.do", method = RequestMethod.GET)
public String result(ModelMap map, String name, int age) {
map.addAttribute("name", name);
map.addAttribute("age", age);
Session session = DbConnections.getSession();
Transaction transaction = session.beginTransaction();
UsersEntity ue = new UsersEntity();
ue.setName(name);
ue.setAge((byte) age);
session.save(ue);
transaction.commit();
session.close();
return "redirect:list.do";
}
}
<%@ page pageEncoding="utf-8" %>
<html>
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<form action="/users/result.do" method="get" >
名字：<input type="text" name="name"/>
年龄：<input type="text" name="age">
<input type="submit" value="submit"/>
</form>
</body>
</html>