（三十一）web 开发基础项目

1.　　编写index.jsp

 <%@ page language="java" contentType="text/html; charset=UTF-8"

     pageEncoding="UTF-8"%>

 <!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>Insert title here</title>

 </head>

 <body>

     <form action="servlet/login?action=add" method="post">

         用户名:<input type="text" name="userName" /><br/>

         密&nbsp;码:<input type="password" name="passWd" /><br/>

         年&nbsp;龄:<input type="text" name="age" /><br/>

         <input type="submit" />

     </form>

 </body>

 </html>

2.　　设计数据库，确定po包、dao包、bo包、service包

　　2.1　　设计数据库

　　2.2　　确定po包，存放的是永久化对象，即与数据库的表一一对应。

userPO.java

 package po;

 import java.util.Date;

 public class UserPO {

     private String userName;

     private String passWd;

     private Date birthday;

     public UserPO(){

     }

     public UserPO(String userName, String passWd, Date birthday) {

         super();

         this.userName = userName;

         this.passWd = passWd;

         this.birthday = birthday;

     }

     public String getUserName() {

         return userName;

     }

     public void setUserName(String userName) {

         this.userName = userName;

     }

     public String getPassWd() {

         return passWd;

     }

     public void setPassWd(String passWd) {

         this.passWd = passWd;

     }

     public Date getBirthday() {

         return birthday;

     }

     public void setBirthday(Date birthday) {

         this.birthday = birthday;

     }

 }

2.3　　确定dao包，包里存的是操作数据的对象（对数据库的增删改查）,一般有接口+实现+工具类.

UserDAOI.java

 package dao;

 import java.util.List;

 import po.UserPO;

 public interface UserDAOI {

     public boolean addUser(UserPO user);

     public boolean delUser(String userName);

     public boolean uptUser(UserPO user);

     public List<UserPO> gets();

 }

DBUtil.java

 package dao;

 import java.beans.PropertyVetoException;

 import java.sql.Connection;

 import java.sql.PreparedStatement;

 import java.sql.ResultSet;

 import java.sql.SQLException;

 import java.text.DateFormat;

 import java.util.ArrayList;

 import java.util.List;

 import com.mchange.v2.c3p0.ComboPooledDataSource;

 import po.UserPO;

 public class DBUtil {

     public static ComboPooledDataSource  dateSource;

     static{

         dateSource=new ComboPooledDataSource();

         final String URL="jdbc:mysql://localhost:3306/user?useUnicode=true&characterEncoding=utf-8";

         final String USER="root";

         final String PASSWD="";

         final String Driver="com.mysql.jdbc.Driver";

         try {

             dateSource.setDriverClass(Driver);

             dateSource.setJdbcUrl(URL);

             dateSource.setUser(USER);

             dateSource.setPassword(PASSWD);

             dateSource.setMaxPoolSize(100);

             dateSource.setMinPoolSize(10);

             dateSource.setMaxStatements(10000);

         } catch (Exception e) {

             e.printStackTrace();

         }

     }

     /**

      *

      * @return 连接池中的连接

      */

     public static Connection getConn(){

         try {

             return dateSource.getConnection();

         } catch (SQLException e) {

             e.printStackTrace();

         }

         return null;

     }

     /**

      *

      * 增删改方法

      * @param sql sql语句

      * @param list sql语句中的？值

      * @return

      */

     public static boolean cud(String sql,List<Object> list){

         boolean flag=false;

         Connection conn=null;

         PreparedStatement pstat=null;

         try{

             conn=getConn();

             pstat=conn.prepareStatement(sql);

             if(list!=null){

                 for(int i=0;i<list.size();i++){

                     pstat.setObject(i+1, list.get(i));

                 }

             }

             int res=pstat.executeUpdate();

             if(res>0){

                 flag=true;

             }

         }catch(Exception e){

             e.printStackTrace();

         }finally{

             close(conn, pstat, null);

         }

         return flag;

     }

     /**

      * 关闭流

      * @param conn 连接流

      * @param pstat    sql语句流

      * @param res    结果集流

      */

     public static void close(Connection conn,PreparedStatement pstat,ResultSet res){

         try{

             if(conn!=null)

             {

                 conn.close();

             }

             if(pstat!=null)

             {

                 pstat.close();

             }if(res!=null)

             {

                 res.close();

             }

         }

         catch(Exception e)

         {

             e.printStackTrace();

         }

     }

     /**查找数据库中所有po对象并返回list
　　　　　*@param sql sql语句
　　　　　*@param list 存放sql预处理语句中的？值
　　　　　*/

     public static List<UserPO> gets(String sql,List<Object> list) {

         List<UserPO> users=new ArrayList<UserPO>();

         UserPO user=null;

         Connection conn=null;

         PreparedStatement pstat=null;

         ResultSet res=null;

         try

         {

             conn=DBUtil.getConn();

             pstat=conn.prepareStatement(sql);

             if(list!=null)

             {

                 for(int i=0;i<list.size();i++)

                 {

                     pstat.setObject(i+1, list.get(i));

                 }

             }

             res=pstat.executeQuery();

             while(res.next())

             {

                 user=new UserPO();

                 user.setUserName(res.getString("userName"));

                 user.setBirthday(res.getDate("birthday"));

                 user.setPassWd(res.getString("passWd"));

                 users.add(user);

             }

         }

         catch(Exception e)

         {

             e.printStackTrace();

         }finally

         {

             close(conn, pstat, res);

         }

         return users;

     }

 }

UserDAOImpl.java

package dao;

import java.awt.geom.CubicCurve2D;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.util.ArrayList;

import java.util.List;

import po.UserPO;

public class UserPOImpl implements UserDAOI {

	public boolean addUser(UserPO user) {

		String sql="insert into user values(?,?,?)";

		List<Object> list=new ArrayList<Object>();

		list.add(user.getUserName());

		list.add(user.getPassWd());

		list.add(user.getBirthday());

		return DBUtil.cud(sql, list);

	}

	public boolean delUser(String userName) {

		String sql="delete from user where userName=?";

		List<Object> list=new ArrayList<Object>();

		list.add(userName);

		return DBUtil.cud(sql, list);

	}

	public boolean uptUser(UserPO user) {

		String sql="update user set passWd=?,birthday=? where userName=?";

		List<Object> list=new ArrayList<Object>();

		list.add(user.getPassWd());

		list.add(user.getBirthday());

		list.add(user.getUserName());

		return DBUtil.cud(sql, list);

	}

	public List<UserPO> gets() {

		String sql="select * from user";

		return DBUtil.gets(sql, null);

	}

}

2.4　　确定bo包，存放的是对象，即与用户提供的信息一一对应。

userBO.java

 package bo;

 public class UserBO {

     private String userName;

     private String passWd;

     private String age;

     public UserBO()

     {

     }

     public UserBO(String userName, String passWd, String age) {

         super();

         this.userName = userName;

         this.passWd = passWd;

         this.age = age;

     }

     public String getUserName() {

         return userName;

     }

     public void setUserName(String userName) {

         this.userName = userName;

     }

     public String getPassWd() {

         return passWd;

     }

     public void setPassWd(String passWd) {

         this.passWd = passWd;

     }

     public String getAge() {

         return age;

     }

     public void setAge(String age) {

         this.age = age;

     }

 }

　　解析： bo对象与po对象不同点在于： bo对象是业务对象，存放的数据是用户直接提供的，以本题为例，用户数据为userName、passWd、age，bo对象成员属性也为这三个，而

po对象则是存放于数据库中的数据，即用户数据经过处理之后才能存放于数据库中（比如用户注册的age数据，如果数据库中直接存放age毫无意义，因为第二年的时候age+1，数据库管理员还得给每个age+1），po对象存放的数据为userName、passWd、birthday。

2.5　确定service包，将servlet得到的原始数据（即用户数据）转换为DAO包里的数据格式。

userServiceI.java

 package service;

 import java.util.List;

 import bo.UserBO;

 public interface UserServiceI {

     public boolean addUser(UserBO user);

     public boolean delUser(String userName);

     public boolean uptUser(UserBO user);

     public List<UserBO> gets();

 }

userServiceImpl.java

 package service;

 import java.util.ArrayList;

 import java.util.Date;

 import java.util.List;

 import bo.UserBO;

 import dao.UserPOImpl;

 import po.UserPO;

 public class UserServiceImpl implements UserServiceI {

     UserPOImpl im=new UserPOImpl();

     public boolean addUser(UserBO user) {

         return im.addUser(bo2po(user));

     }

     public boolean delUser(String userName) {

         im.delUser(userName);

         return true;

     }

     public boolean uptUser(UserBO user) {

         return im.uptUser(bo2po(user));

     }

     public List<UserBO> gets() {

         List<UserPO> poList=im.gets();

         return po2bo(poList);

     }

     /**

      * 把BO对象转为PO对象，这个方法只适用于增加和修改操作

      *

      * @param user

      * @return

      */

     private UserPO bo2po(UserBO user)

     {

         UserPO userpo=new UserPO();

         Date date=new Date();

         @SuppressWarnings("deprecation")

         int year=date.getYear(); //拿到今年第几年

         int yearDB=year-Integer.parseInt(user.getAge()); //得到存入数据库的年份

         @SuppressWarnings("deprecation")

         Date date1=new Date(yearDB,date.getMonth(),date.getDay());

         userpo.setBirthday(date1);

         userpo.setUserName(user.getUserName());

         userpo.setPassWd(user.getPassWd());

         return userpo;

     }

     /**

      * 把存有PO对象的List转为存有BO对象的List

      * 步骤：

      *  1. 拿到存有PO对象的list容器之后，进行遍历

      *     2.  每次遍历都要new一个BO对象，然后把PO对象的值对应转化为BO对象

      *     3. 返回存放BO对象的list

      * @param userpo

      * @return BO对象

      */

     private List<UserBO> po2bo(List<UserPO> poList)

     {

         List<UserBO> boList=new ArrayList<UserBO>();

         UserBO userbo=null;

         for(int i=0;i<poList.size();i++)

         {

             userbo=new UserBO();

             userbo.setUserName(poList.get(i).getUserName());

             userbo.setPassWd(poList.get(i).getPassWd());

             Date birthday=poList.get(i).getBirthday();

             Date getYear=new Date();

             int age=getYear.getYear()-birthday.getYear();

             userbo.setAge(String.valueOf(age));

             boList.add(userbo);

         }

         return boList;

     }

 }

3. 编写servlet包

LoginServlet.java

package srevlet;

import java.io.IOException;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import bo.UserBO;

import service.UserServiceImpl;

public class LoginServlet extends HttpServlet {

    private static final long serialVersionUID = 1L;

    public LoginServlet() {

        super();

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        this.doPost(request, response);

    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        //拿到用户数据

        UserBO user=null;

        UserServiceImpl userIm=new UserServiceImpl();

        String userName=request.getParameter("userName");

        String passWd=request.getParameter("passWd");

        String age=request.getParameter("age");

        String action=request.getParameter("action");

        if(action.equals("add"))

        {

            //增加一条记录

            user=new UserBO();

            user.setUserName(userName);

            user.setPassWd(passWd);

            user.setAge(age);

            userIm.addUser(user);

        }

        if(action.equals("del"))

        {

            //删除一条记录

            String name=request.getParameter("userName");

            userIm.delUser(name);

        }

        if(action.equals("upt"))

        {

            user=new UserBO();

            user.setAge(request.getParameter("age"));

            user.setPassWd(request.getParameter("passWd"));

            user.setUserName(request.getParameter("userName"));

            userIm.uptUser(user);

        }

        if(action.equals("gets"))

        {

            //拿到数据库的全部数据

            List<UserBO> listbo=userIm.gets();

            for(int i=0;i<listbo.size();i++)

            {

                System.out.println(listbo.get(i).getUserName()+" "+listbo.get(i).getAge()+" "+listbo.get(i).getPassWd());

            }

        }

    }

}

结果：

解析：查看servlet 当action=del的时候，会执行servlet的相应操作，request.getParameter("userName"); 可以得到地址栏里的userName的值“nihao”，这样就可以从数据库中删除。

巴特西

（三十一）web 开发基础项目

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