javaweb常用工具类及配置文件备份
Javaweb常用工具类及配置文件备份
做一个代码备份，以后常用到的。
hibernate工具类备份
package com.dly.service;/* * hibernate获取session 的工具类 */import java.io.Serializable;import org.hibernate.SessionFactory;import org.hibernate.Transaction;import org.hibernate.cfg.Configuration;import org.hibernate.Session;public final class HibernateUtil { private static SessionFactory sessionFactory; public static SessionFactory getSessionFactory() { return sessionFactory; } private HibernateUtil(){}static{ Configuration cfg=new Configuration(); cfg.configure();//配置文件名 sessionFactory=cfg.buildSessionFactory();}public static Session getSession(){ return sessionFactory.openSession(); }/** * 添加信息 * @param entity */public static void add(Object entity){ Session s=null; Transaction tx=null; try{ s=HibernateUtil.getSession(); tx=s.beginTransaction(); s.save(entity); tx.commit(); }finally{ if(s!=null){ s.close(); } }}/** * 更新信息 * @param entity */public static void update(Object entity){ Session s=null; Transaction tx=null; try{ s=HibernateUtil.getSession(); tx=s.beginTransaction(); s.update(entity); tx.commit(); }finally{ if(s!=null){ s.close(); } }}/** * 删除信息 * @param entity */public static void delete(Object entity){ Session s=null; Transaction tx=null; try{ s=HibernateUtil.getSession(); tx=s.beginTransaction(); s.delete(entity); tx.commit(); }finally{ if(s!=null){ s.close(); } }}/** * 根据id查询 * @param clazz * @param id * @return */public static Object get(Class clazz,Serializable id){ Session s=null; try{ s=HibernateUtil.getSession(); Object obj=s.get(clazz, id); return obj; }finally{ if(s!=null){ s.close(); } }}} |
操作数据库举例：
package com.dly.service;import java.util.List;import org.hibernate.Query;import org.hibernate.Session;import com.dly.entity.Users;public class UserDao { public static String queryByname(String name){ Session s=null; String result=null; //System.out.println("调用了"); try{ s=HibernateUtil.getSession(); String hql="from Users as user where user.username=:username";//里面User是类名，不是表名，为类名起别名user，查询的是对象 Query query=s.createQuery(hql); query.setString("username", name); Users u=(Users) query.uniqueResult();//确定只有一个数据，限制用户名唯一时使用 // System.out.println(u.getUsername()); if(u!=null){ result=u.getUsername(); System.out.println(result); } return result; }finally{ if(s!=null){ s.close(); } } } public static Users queryByusername(String username,String pwd){ Users user=null; Session s=null; try{ s=HibernateUtil.getSession(); String hql="from Users as users where users.username=:username";//里面User是类名，不是表名，为类名起别名user，查询的是对象 Query query=s.createQuery(hql); query.setString("username", username); List<Users>list =query.list(); for(Users users:list){ String u=users.getUsername(); String p=users.getPassword(); if(u.equals(username)&&p.equals(pwd)){ user=users; } } return user; }finally{ if(s!=null){ s.close(); } } } } |
servlet常用代码举例：
package com.dly.servlet;import java.io.IOException;import java.util.ArrayList;import java.util.Iterator;import java.util.List;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.json.JSONArray;import com.dly.entity.Shop;import com.dly.service.BuyCarDao;import com.dly.service.HibernateUtil;@WebServlet("/BuyCarList")public class BuyCarList extends HttpServlet { private static final long serialVersionUID = 1L; // Class clazz=BuyCar.class; Class<Shop> clazz=Shop.class; List<Shop> shop=new ArrayList<Shop>(); protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); int userid=Integer.parseInt(request.getParameter("userid")); List<Integer> list=new ArrayList<Integer>(); list=BuyCarDao.querayByuserid(userid); Iterator<Integer> it=list.iterator(); List<Shop>shop=new ArrayList<Shop>(); while(it.hasNext()){ int shopid=(Integer) it.next(); shop.add((Shop) HibernateUtil.get(clazz, shopid)); } JSONArray shoplist=new JSONArray(shop); response.getWriter().println(shoplist.toString()); }} |
package com.dly.servlet;import java.io.IOException;import javax.servlet.ServletException;import javax.servlet.annotation.WebServlet;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import com.dly.entity.BuyCar;import com.dly.service.BuyCarDao;import com.dly.service.HibernateUtil;@WebServlet("/AddBuyCar")public class AddBuyCar extends HttpServlet { private static final long serialVersionUID = 1L; protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { doPost(request, response); } protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { request.setCharacterEncoding("UTF-8"); response.setContentType("text/html;charset=UTF-8"); BuyCar buycar; int shopid = Integer.parseInt(request.getParameter("shopid")); int userid=Integer.parseInt(request.getParameter("userid")); BuyCar result =BuyCarDao.queryByshopid(shopid); if(result==null){ buycar=new BuyCar(); buycar.setShopid(shopid); buycar.setUserid(userid); HibernateUtil.add(buycar); response.getWriter().print("添加成功"); response.getWriter().flush(); }else{ response.getWriter().print("该商品已在购物车中"); response.getWriter().flush(); } }} |
hibernate配置文件编写
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-configuration PUBLIC "-//Hibernate/Hibernate Configuration DTD 3.0//EN"<hibernate-configuration> <session-factory> <!-- 映射文件 --> <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property> <property name="connection.url">jdbc:mysql://localhost:3306/trade?useUnicode=true&characterEncoding=UTF-8</property> <property name="connection.username">root</property> <property name="connection.password"></property> <property name="dialect"> org.hibernate.dialect.MySQLDialect</property> <mapping resource="com/dly/entity/Users.hbm.xml"/> </session-factory> </hibernate-configuration> |
Users.hbm.xml
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<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" <hibernate-mapping package="com.dly.entity"> <class name="Users" table="users" > <!-- id值 --> <id name="userid" type="int" length="11"> <generator class="native"/> </id> <property name="username" type="string" length="32" column="username"></property> <property name="password" type="string" length="32" column="password"></property> <property name="school" type="string" length="64" column="school"></property> <property name="userphone" type="string" length="32" column="userphone"></property> </class> </hibernate-mapping> |
此代码正在完善中。。。。。。
