Hibernate核心组件入门
Hibernate核心组件入门
在Hibernate开发中关键一点就是使用Hibernate的核心类和接口，它位于业务层和持久化层之间，它除了核心组件外还包括它的配置文件（hibernate.cfg.xml或者hibernate.properties）,映射文件（XXX.hbm.xml）和持久化对象。
1：Configuration
主要负责配置并且启动hibernate，创建SessionFactory对象，在启动的时候，Configuration首先定位到映射文件的位置，读取配置，然后创建sessionFactory对象。
2：SessionFactory
负责初始化Hibernate，它充当数据存储源的代理，并且负责创建session对象，这里用到了工厂的模式，SesionFactory不是轻量级的，所以一个项目就需要一个SessionFactory,当需要多次操作数据库的时候，可以为每一个数据库制定一个sessionfactory线程对象，sessionfactory是产生session的工厂。
3：Session
负责执行持久化对象的操作它用get(),load(),save(),update()delete()等方法对PO进行加载，保存更新及删除等操作。Session对象是非线程安全的。
4:Transaction
管理Hibernate的事务，它的主要的方法是commit(),和rollback().Session的beginTransation()方法可以生成该对象。
5：Query
负责各种数据库的查询，可以使用HQL语言对PO进行查询操作，Query对象可以由Session的createQuery的方法生成。
下面是一个简单的基于Struts-Hibernate的登录注册系统：
1：首先需要引入需要的架包
2：编写web.xml文件
<?xml version="1.0" encoding="UTF-8"?> <web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"> <filter> <filter-name>struts2</filter-name> <filter-class>org.apache.struts2.dispatcher.FilterDispatcher</filter-class> </filter> <filter-mapping> <filter-name>struts2</filter-name> <url-pattern>/*</url-pattern> </filter-mapping> <session-config> <session-timeout> 30 </session-timeout> </session-config> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> </web-app>
3：还需要写一个struts.xml文件，这个文件是处理逻辑的和数据库的hibernate.cfg.xml文件
<!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.0//EN" "http://struts.apache.org/dtds/struts-2.0.dtd"> <struts> <package name="default" extends="struts-default"> <action name="login" class="action.LoginAction"> <result name="success">/success.jsp</result> <result name="input">/login.jsp</result> <result name="error">/login.jsp</result> </action> <action name="register" class="action.RegisterAction"> <result name="success">/login.jsp</result> <result name="input">/register.jsp</result> <result name="error">/register.jsp</result> </action> </package> </struts>
<?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"> <hibernate-configuration> <session-factory> <property name="hibernate.dialect">org.hibernate.dialect.MySQLDialect</property> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/db_loginRegis</property> <property name="hibernate.connection.username">root</property> <property name="hibernate.connection.password">root</property> <mapping resource="PO/UserInfoPO.hbm.xml"/> </session-factory> </hibernate-configuration>
4:编写登录的界面
<%@ page language="java" contentType="text/html; charset=utf-8" pageEncoding="utf-8"%> <%@taglib prefix="s" uri="/struts-tags" %><!-- 引入struts标签 --> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <title>SH登录和注册系统</title> </head> <body bgcolor = "green"> <s:form action="login" method="post"> <br><br><br><br><br><br> <table border = "1" align="center" bgcolor="red"> <tr> <td><s:textfield name="userName" label="用户名" size="16"></s:textfield> </td> </tr> <tr> <td><s:textfield name="password" label="用户密码" size="16"></s:textfield> </td> </tr> <tr> <td colspan="2" align="left"> <s:submit value="登录"></s:submit> </td> </tr> <tr> <td colspan = "2" align = "center"> <s:a href ="http://localhost:8080/SH_Login/register.jsp">注册</s:a> </td> </tr> </table> </s:form> </body> </html>
注册界面：
<%@page contentType="text/html" pageEncoding="UTF-8"%> <%@taglib prefix="s" uri="/struts-tags" %> <!DOCTYPE html> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> </head> <body bgcolor="#CCCCFF"> <s:form action="register" method="post"> <br><br><br><br><br><br> <table border="1" align="center" bgcolor="red"> <tr> <td> <s:textfield name="userName" label="用户名字" size="16"/> </td> </tr> <tr> <td> <s:password name="password1" label="用户密码" size="18"/> </td> </tr> <tr> <td> <s:password name="password2" label="再次输入密码" size="18"/> </td> </tr> <tr> <td colspan="2" align="center"> <input type="submit" value="提交"/> <input type="reset" value="清空"/> </td> </tr> <tr> <td colspan="2" align="center"> <s:a href="/login.jsp">返回</s:a> </td> </tr> </table> </s:form> </body> </html>
工具类：
package Util; import org.hibernate.Session; import org.hibernate.SessionFactory; import org.hibernate.cfg.Configuration; public class HibernateSessionFactory { private SessionFactory sessionFactory; public HibernateSessionFactory(){ } public SessionFactory config(){ try{ Configuration configuration=new Configuration(); Configuration configure = configuration.configure("hibernate.cfg.xml"); return configure.buildSessionFactory(); }catch(Exception e){ e.getMessage(); return null; } } public Session getSession(){ sessionFactory=config(); return sessionFactory.openSession(); } }
action业务逻辑处理
package action; import com.opensymphony.xwork2.ActionSupport; import Dao.LoginRegisterInfo; import PO.UserInfoPO; import java.util.List; public class LoginAction extends ActionSupport{ private String userName; private String password; private String message="error"; private List list; public String getUserName() { return userName; } public void setUserName(String userName) { this.userName = userName; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public void validate(){ if(this.getUserName()==null||this.getUserName().length()==0){ addFieldError("userName","用户名不能为空！"); }else{ LoginRegisterInfo info=new LoginRegisterInfo(); list=info.queryInfo("userName", this.getUserName()); if(list.size()==0){ addFieldError("userName","该用户尚未注册！"); }else{ UserInfoPO ui=new UserInfoPO(); int count=0; for(int i=0;i<list.size();i++){ count++; ui=(UserInfoPO)list.get(i); if(this.getUserName().equals(ui.getUserName())){ if(ui.getPassword().equals(this.getPassword())){ message="success"; }else{ addFieldError("password","登录密码不正确！"); } } } } } } public String execute() throws Exception{ return message; } }
package action; import PO.UserInfoPO; import com.opensymphony.xwork2.ActionSupport; import Dao.LoginRegisterInfo; import java.util.List; public class RegisterAction extends ActionSupport{ private String userName; private String password1; private String password2; private String mess="error"; private List list; public String getUserName() { return userName; } public void setUserName(String userName) { this.userName= userName; } public String getPassword1() { return password1; } public void setPassword1(String password1) { this.password1 = password1; } public String getPassword2() { return password2; } public void setPassword2(String password2) { this.password2 = password2; } public void validate(){ if(this.getUserName()==null||this.getUserName().length()==0){ addFieldError("userName","用户名不能为空！"); }else{ LoginRegisterInfo info=new LoginRegisterInfo(); list=info.queryInfo("userName", this.getUserName()); UserInfoPO ui=new UserInfoPO(); for(int i=0;i<list.size();i++){ ui=(UserInfoPO)list.get(i); if(ui.getUserName().equals(this.getUserName())){ addFieldError("userName","用户名已存在！"); } } } if(this.getPassword1()==null||this.getPassword1().length()==0){ addFieldError("password1","登录密码不允许为空！"); }else if(this.getPassword2()==null||this.getPassword2().length()==0){ addFieldError("password2","重复密码不允许为空！"); }else if(!this.getPassword1().equals(this.getPassword2())){ addFieldError("password2","两次密码不一致！"); } } public UserInfoPO userInfo(){ UserInfoPO info=new UserInfoPO(); info.setUserName(this.getUserName()); info.setPassword(this.getPassword1()); return info; } public String execute() throws Exception{ LoginRegisterInfo lr=new LoginRegisterInfo(); String ri=lr.saveInfo(userInfo()); if(ri.equals("success")){ mess="success"; } return mess; } }
Dao的编写:
package Dao; import Util.HibernateSessionFactory; import PO.UserInfoPO; import java.util.List; import javax.swing.JOptionPane; import org.hibernate.Query; import org.hibernate.Session; import org.hibernate.Transaction; public class LoginRegisterInfo { private Session session; private Transaction transaction; private Query query; HibernateSessionFactory getSession; public LoginRegisterInfo(){ } public String saveInfo(UserInfoPO info){ String mess="error"; getSession=new HibernateSessionFactory(); session=getSession.getSession(); try{ transaction=session.beginTransaction(); session.save(info); transaction.commit(); mess="success"; return mess; }catch(Exception e){ message("RegisterInfo.error:"+e); e.printStackTrace(); return null; } } public List queryInfo(String type,Object value){ getSession=new HibernateSessionFactory(); session=getSession.getSession(); try{ String hqlsql="from UserInfoPO as u where u.userName=?"; query=session.createQuery(hqlsql); query.setParameter(0, value); List list=query.list(); transaction=session.beginTransaction(); transaction.commit(); return list; }catch(Exception e){ message("LoginRegisterInfo类中有异常，异常为:"+e); e.printStackTrace(); return null; } } public void message(String mess){ int type=JOptionPane.YES_NO_OPTION; String title="提示信息"; JOptionPane.showMessageDialog(null, mess, title, type); } }
映射文件：
<?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="PO.UserInfoPO" table="info" catalog="db_loginRegis"> <id name="id" type="int"> <column name="id"/> <generator class="native"/> </id> <property name="userName" type="string"> <column name="userName" length="30" not-null="true"/> </property> <property name="password" type="string"> <column name="password" length="30" not-null="true"/> </property> </class> </hibernate-mapping>
