jsp+servlet+javabean开发web项目

一.介绍：

　　项目依赖包：jdbc数据库包

　　jsp+servlet+javabean开发web项目，是最接近web项目原生运行原理的。

　　但是，jsp内容混乱，项目结构复杂时，代码会混乱

二.运行原理：

　　jsp发出请求到web--

　　web接收请求并匹配请求对应的servlet--

　　servlet调用数据库dao层操作数据库--

　　如果有数据传递，放到request或者session中

　　重点：servlet会执行doService()方法来判断调用doGet()或者doPost()

三.开发步骤：

1.新建web项目

2.新建实体类　　User.java

package com.mart.bean;

public class User {
    
    //属性
    private Integer id;
    private String uname;
    private String upass;
    private String tname;
    private String utype;
    //属性访问
    public Integer getId() {
        return id;
    }
    public void setId(Integer id) {
        this.id = id;
    }
    public String getUname() {
        return uname;
    }
    public void setUname(String uname) {
        this.uname = uname;
    }
    public String getUpass() {
        return upass;
    }
    public void setUpass(String upass) {
        this.upass = upass;
    }
    public String getTname() {
        return tname;
    }
    public void setTname(String tname) {
        this.tname = tname;
    }
    public String getUtype() {
        return utype;
    }
    public void setUtype(String utype) {
        this.utype = utype;
    }
    
    //构造
    public User() {
        super();
        // TODO Auto-generated constructor stub
    }
    public User(Integer id, String uname, String upass, String tname,
            String utype) {
        super();
        this.id = id;
        this.uname = uname;
        this.upass = upass;
        this.tname = tname;
        this.utype = utype;
    }
    public User(String uname, String upass, String tname, String utype) {
        super();
        this.uname = uname;
        this.upass = upass;
        this.tname = tname;
        this.utype = utype;
    }
    //更新操作改善,不加name更新
    public User(Integer id, String upass, String tname, String utype) {
        super();
        this.id = id;
        this.upass = upass;
        this.tname = tname;
        this.utype = utype;
    }
    
    //tostring
    @Override
    public String toString() {
        return "User [id=" + id + ", uname=" + uname + ", upass=" + upass
                + ", tname=" + tname + ", utype=" + utype + "]";
    }
    
    
}

3.编写操作接口　　UserDao.java

package com.mart.dao;

import java.util.List;

import com.mart.bean.User;

public interface UserDao {
    /**
     * @param u 待添加的用户
     * @return 0-添加失败  1-添加成功 
     */
    public Integer addUser(User u);
    /**
     * @param id 待删除用户编号
     * @return 0-删除失败  1-删除成功
     */
    public Integer delUser(Integer id);
    /**
     * @param u 要添加的用户
     * @return 0-更新失败  1-更新成功
     */
    public Integer updUser(User u);
    /**
     * @param id 待查找的用户编号
     * @return 要查找的用户
     */
    public User findUserById(Integer id);
    /**
     * @return 全部用户列表
     */
    public List<User> FindAllUser();
    
    
}

4.编写数据库操作工具类　　DBUtil.java

package com.mart.util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DBUtil {
    
    //获取oracle数据库连接
    public Connection getCurrentConnection(){
        //初始返回值
        Connection conn = null;
        
        try {
            //加载驱动
            Class.forName("oracle.jdbc.driver.OracleDriver");
            conn = DriverManager.getConnection("jdbc:oracle:thin:@127.0.0.1:1521:orcl", 
                                                "mart", "java");
            
            
        } catch (ClassNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        
        return conn;
    }
}

5.编写接口实现　　UserDaoImpl.java

package com.mart.dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.mart.bean.User;
import com.mart.dao.UserDao;
import com.mart.util.DBUtil;

public class UserDaoImpl implements UserDao{

    @Override
    public Integer addUser(User u) {
        // TODO Auto-generated method stub
        int res=-1;
        //连接数据库
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //添加语句
        PreparedStatement ps = null;
        String sql = "insert into mart_user values(seq_mart_user.nextval,?,?,?,?)";
        
        try {
            ps = conn.prepareStatement(sql);
            ps.setString(1, u.getUname());
            ps.setString(2, u.getUpass());
            ps.setString(3, u.getTname());
            ps.setString(4, u.getUtype());
            //执行
            res = ps.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(ps!=null)ps.close();
                if(conn!=null)conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return res;
    }

    @Override
    public Integer delUser(Integer id) {
        // TODO Auto-generated method stub
        int res=-1;
        //连接数据库
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //删除语句
        PreparedStatement ps = null;
        String sql = "delete from mart_user where id=?";
        try {
            ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            //执行
            res = ps.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(ps!=null)ps.close();
                if(conn!=null)conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return res;
    }

    @Override
    public Integer updUser(User u) {
        // TODO Auto-generated method stub
        int res=-1;
        //连接数据库
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //更新语句
        PreparedStatement ps = null;
        String sql = "update mart_user set upass=?,tname=?,utype=? where id=?";
        
        try {
            ps = conn.prepareStatement(sql);
//            ps.setString(1, u.getUname());--完善更改，不设置名字
            ps.setString(1, u.getUpass());
            ps.setString(2, u.getTname());
            ps.setString(3, u.getUtype());
            ps.setInt(4, u.getId());
            //执行
            res = ps.executeUpdate();
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(ps!=null)ps.close();
                if(conn!=null)conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return res;
    }

    @Override
    public User findUserById(Integer id) {
        // TODO Auto-generated method stub
        User u = null;
        //连接数据库
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //查找语句
        PreparedStatement ps = null;
        ResultSet rs = null;
        String sql = "select * from mart_user where id=?";
        
        try {
            ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            //获取结果
            rs = ps.executeQuery();
            rs.next();
            u = new User(rs.getInt("id"), rs.getString("uname"), rs.getString("upass"), 
                            rs.getString("tname"), rs.getString("utype"));
            
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(rs!=null)rs.close();
                if(ps!=null)ps.close();
                if(conn!=null)conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return u;
    }

    @Override
    public List<User> FindAllUser() {
        // TODO Auto-generated method stub
        List<User> uList = new ArrayList<User>();
        //连接数据库
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //查找语句
        PreparedStatement ps = null;
        ResultSet rs = null;
        String sql = "select * from mart_user";
        
        try {
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            //获取结果
            while(rs.next()){
                uList.add(new User(rs.getInt("id"), rs.getString("uname"), rs.getString("upass"), 
                            rs.getString("tname"), rs.getString("utype")));
            }
        } catch (SQLException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }finally{
            try {
                if(rs!=null)rs.close();
                if(ps!=null)ps.close();
                if(conn!=null)conn.close();
            } catch (SQLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
        
        return uList;
    }

}

 6.编写测试文件，测试是否底层数据操作成功　　UserTest.java

package com.mart.test;

import java.util.ArrayList;
import java.util.List;

import com.mart.bean.User;
import com.mart.dao.impl.UserDaoImpl;

public class UserTest {
    //主测试
    public static void main(String[] args) {
        //实例化实现
        UserDaoImpl udi = new UserDaoImpl();
        
//        addTest(udi);
//        delTest(udi);
//        updTest(udi);
//        findTest(udi);
//        findAllTest(udi);
        
    }
    
    //添加测试
    private static void addTest(UserDaoImpl udi){
        //设置添加对象
        User u = new User("wangwu", "0002", "王五", "0");
        Integer res = udi.addUser(u);
        if(res>0){
            System.out.println("添加成功");
        }else{
            System.out.println("添加失败");
        }
    }
    //删除测试
    private static void delTest(UserDaoImpl udi){
        //设置删除编号
        int id = 2;
        int res = udi.delUser(id);
        if(res>0){
            System.out.println("删除成功");
        }else{
            System.out.println("删除失败");
        }
    }
    //更新测试
    private static void updTest(UserDaoImpl udi){
        //设置更新对象
        User u = new User(9, "tiqi", "123", "田七", "0");
        Integer res = udi.updUser(u);
        if(res>0){
            System.out.println("更新成功");
        }else{
            System.out.println("更新失败");
        }
    }
    //id查找测试
    private static void findTest(UserDaoImpl udi){
        //设置查找id
        int id = 6;
        User u =udi.findUserById(id);
        System.out.println(u);
    }
    //全部查找
    private static void findAllTest(UserDaoImpl udi){
        //新建保存集
        List<User> uList = new ArrayList<User>();
        uList = udi.FindAllUser();
        for (User user : uList) {
            System.out.println(user);
        }
    }
    
    
}

7.编写jsp显示界面,仅以用户显示界面为例　　show.jsp

<%@page import="com.mart.bean.User"%>
<%@page import="com.mart.dao.impl.UserDaoImpl"%>
<%@page import="com.mart.dao.UserDao"%>
<%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%>
<html>
  <head>
    <title>用户显示</title>    
    <meta http-equiv="pragma" content="no-cache">
    <meta http-equiv="cache-control" content="no-cache">
    <meta http-equiv="expires" content="0">    
    <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
    <meta http-equiv="description" content="This is my page">    
  </head>
  
  <body>
    <div class="top" style=" 800px;height: 50px">
        <h3>用户显示界面</h3>
    </div>
    <div class="center" style=" 800px;height: auto;">
        <table border="1">
            <tr>
                <th>用户编号</th>
                <th>用户账户</th>
                <th>用户密码</th>
                <th>真实名字</th>
                <th>用户类型</th>
                <th>用户操作</th>
            </tr>
            <tr>
               <%
                   //实例化接口
                   UserDao udi = new UserDaoImpl();
                   List<User> uList = new ArrayList<User>();
                   uList = udi.FindAllUser();
                   for(User u : uList){
                %>
                    <tr>
                        <td>
                            <%=u.getId() %>
                        </td>
                        <td>
                            <%=u.getUname() %>
                        </td>
                        <td>
                            <%=u.getUpass() %>
                        </td>
                        <td>
                            <%=u.getTname() %>
                        </td>
                        <td>
                            <%=u.getUtype().equals("0")?"普通":"管理员" %>
                        </td>
                        <td>
                            <a href="upd.jsp?id=<%=u.getId() %>&uname=<%=u.getUname()%>&
                                            upass=<%=u.getUpass() %>&tname=<%=u.getTname()%>&
                                            utype=<%=u.getUtype() %>">更新</a>
                            /<a href="../del.do?id=<%=u.getId() %>">删除</a>
                        </td>
                    </tr>
                <%
                   }
                %>
            </tr>
            <tr>
                <td colspan="6" align="center">
                    <a href="./add.jsp">用户添加</a>
                </td>
            </tr>
        </table>
    </div>
    
  </body>
</html>

8.编写servlet文件　　ShowAction.java

package com.mart.controller;

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 com.mart.bean.User;
import com.mart.dao.UserDao;
import com.mart.dao.impl.UserDaoImpl;

public class ShowAction extends HttpServlet {

    //解析请求方法
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        System.out.println("用户展示界面：com.mart.controller.show");
        //获取用户列表
        UserDao udi = new UserDaoImpl();
        List<User> uList = udi.FindAllUser();
        //传递用户列表到前断
        //此处用session则服务器过载
        request.setAttribute("uList", uList);
        //转到显示界面
        //不能重定向，会丢失数据
        response.sendRedirect("user/show.jsp");
        
    }

    //响应请求方法
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        /**
         * get和post行为相同时，直接设置内部调用即可
         */
        this.doGet(request, response);
    }

}

 8.在web.xml里注册servlet

<?xml version="1.0" encoding="UTF-8"?>
<web-app version="2.5" 
    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_2_5.xsd">
  <display-name>淘宝商城servlet-xml配置</display-name>
  <servlet>
    <description>这是我的用户显示界面，显示全部用户</description>
    <display-name>user_show</display-name>
    <servlet-name>ShowAction</servlet-name>
    <servlet-class>com.mart.controller.ShowAction</servlet-class>
  </servlet>
  <servlet>
    <description>这是我的用户添加界面</description>
    <display-name>user_add</display-name>
    <servlet-name>AddAction</servlet-name>
    <servlet-class>com.mart.controller.AddAction</servlet-class>
  </servlet>
  <servlet>
    <description>这是我的用户删除界面</description>
    <display-name>user_delete</display-name>
    <servlet-name>DeleteAction</servlet-name>
    <servlet-class>com.mart.controller.DeleteAction</servlet-class>
  </servlet>
  <servlet>
    <description>这是我的用户更新界面</description>
    <display-name>user_update</display-name>
    <servlet-name>UpdateAction</servlet-name>
    <servlet-class>com.mart.controller.UpdateAction</servlet-class>
  </servlet>




  <servlet-mapping>
    <servlet-name>ShowAction</servlet-name>
    <url-pattern>/show.do</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>AddAction</servlet-name>
    <url-pattern>/add.do</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>DeleteAction</servlet-name>
    <url-pattern>/del.do</url-pattern>
  </servlet-mapping>
  <servlet-mapping>
    <servlet-name>UpdateAction</servlet-name>
    <url-pattern>/upd.do</url-pattern>
  </servlet-mapping>    
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>