正文

javaweb常用工具类及配置文件备份

IP云
IP云V管理员/7 阅读
07/24
提示：扫一扫查出行
【扫一扫了解最新限行尾号】
复制提示

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"
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<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

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
<?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 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。。。。。。