jsp+servlet+javabean開發web項目

時間 2020-08-19

標籤 jsp+servlet+javabean jsp servlet javabean 開發 web 項目欄目 JSP 简体版

原文原文鏈接

一.介紹：html

　　項目依賴包：jdbc數據庫包java

　　jsp+servlet+javabean開發web項目，是最接近web項目原生運行原理的。web

　　可是，jsp內容混亂，項目結構複雜時，代碼會混亂sql

二.運行原理：數據庫

　　jsp發出請求到web--服務器

　　web接收請求並匹配請求對應的servlet--session

　　servlet調用數據庫dao層操做數據庫--oracle

　　若是有數據傳遞，放到request或者session中app

　　重點：servlet會執行doService()方法來判斷調用doGet()或者doPost()jsp

三.開發步驟：

1.新建web項目

2.新建實體類　　User.java

 1 package com.mart.bean;
 2 
 3 public class User {
 4     
 5     //屬性
 6     private Integer id;
 7     private String uname;
 8     private String upass;
 9     private String tname;
10     private String utype;
11     //屬性訪問
12     public Integer getId() {
13         return id;
14     }
15     public void setId(Integer id) {
16         this.id = id;
17     }
18     public String getUname() {
19         return uname;
20     }
21     public void setUname(String uname) {
22         this.uname = uname;
23     }
24     public String getUpass() {
25         return upass;
26     }
27     public void setUpass(String upass) {
28         this.upass = upass;
29     }
30     public String getTname() {
31         return tname;
32     }
33     public void setTname(String tname) {
34         this.tname = tname;
35     }
36     public String getUtype() {
37         return utype;
38     }
39     public void setUtype(String utype) {
40         this.utype = utype;
41     }
42     
43     //構造
44     public User() {
45         super();
46         // TODO Auto-generated constructor stub
47     }
48     public User(Integer id, String uname, String upass, String tname,
49             String utype) {
50         super();
51         this.id = id;
52         this.uname = uname;
53         this.upass = upass;
54         this.tname = tname;
55         this.utype = utype;
56     }
57     public User(String uname, String upass, String tname, String utype) {
58         super();
59         this.uname = uname;
60         this.upass = upass;
61         this.tname = tname;
62         this.utype = utype;
63     }
64     //更新操做改善,不加name更新
65     public User(Integer id, String upass, String tname, String utype) {
66         super();
67         this.id = id;
68         this.upass = upass;
69         this.tname = tname;
70         this.utype = utype;
71     }
72     
73     //tostring
74     @Override
75     public String toString() {
76         return "User [id=" + id + ", uname=" + uname + ", upass=" + upass
77                 + ", tname=" + tname + ", utype=" + utype + "]";
78     }
79     
80     
81 }

3.編寫操做接口　　UserDao.java

package com.mart.dao;

import java.util.List;

import com.mart.bean.User;

public interface UserDao {
    /**
     * @param u 待添加的用戶
     * @return 0-添加失敗  1-添加成功 
     */
    public Integer addUser(User u);
    /**
     * @param id 待刪除用戶編號
     * @return 0-刪除失敗  1-刪除成功
     */
    public Integer delUser(Integer id);
    /**
     * @param u 要添加的用戶
     * @return 0-更新失敗  1-更新成功
     */
    public Integer updUser(User u);
    /**
     * @param id 待查找的用戶編號
     * @return 要查找的用戶
     */
    public User findUserById(Integer id);
    /**
     * @return 所有用戶列表
     */
    public List<User> FindAllUser();
    
    
}

4.編寫數據庫操做工具類　　DBUtil.java

package com.mart.util;

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

public class DBUtil {
    
    //獲取oracle數據庫鏈接
    public Connection getCurrentConnection(){
        //初始返回值
        Connection conn = null;
        
        try {
            //加載驅動
            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.編寫接口實現　　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;
        //鏈接數據庫
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //添加語句
        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());
            //執行
            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;
        //鏈接數據庫
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //刪除語句
        PreparedStatement ps = null;
        String sql = "delete from mart_user where id=?";
        try {
            ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            //執行
            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;
        //鏈接數據庫
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //更新語句
        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，不設置名字
            ps.setString(1, u.getUpass());
            ps.setString(2, u.getTname());
            ps.setString(3, u.getUtype());
            ps.setInt(4, u.getId());
            //執行
            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;
        //鏈接數據庫
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //查找語句
        PreparedStatement ps = null;
        ResultSet rs = null;
        String sql = "select * from mart_user where id=?";
        
        try {
            ps = conn.prepareStatement(sql);
            ps.setInt(1, id);
            //獲取結果
            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>();
        //鏈接數據庫
        DBUtil dbUtil = new DBUtil();
        Connection conn = dbUtil.getCurrentConnection();
        //查找語句
        PreparedStatement ps = null;
        ResultSet rs = null;
        String sql = "select * from mart_user";
        
        try {
            ps = conn.prepareStatement(sql);
            rs = ps.executeQuery();
            //獲取結果
            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.編寫測試文件，測試是否底層數據操做成功　　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 {
    //主測試
    public static void main(String[] args) {
        //實例化實現
        UserDaoImpl udi = new UserDaoImpl();
        
//        addTest(udi);
//        delTest(udi);
//        updTest(udi);
//        findTest(udi);
//        findAllTest(udi);
        
    }
    
    //添加測試
    private static void addTest(UserDaoImpl udi){
        //設置添加對象
        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("添加失敗");
        }
    }
    //刪除測試
    private static void delTest(UserDaoImpl udi){
        //設置刪除編號
        int id = 2;
        int res = udi.delUser(id);
        if(res>0){
            System.out.println("刪除成功");
        }else{
            System.out.println("刪除失敗");
        }
    }
    //更新測試
    private static void updTest(UserDaoImpl udi){
        //設置更新對象
        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("更新失敗");
        }
    }
    //id查找測試
    private static void findTest(UserDaoImpl udi){
        //設置查找id
        int id = 6;
        User u =udi.findUserById(id);
        System.out.println(u);
    }
    //所有查找
    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.編寫jsp顯示界面,僅以用戶顯示界面爲例　　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>用戶顯示</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="width: 800px;height: 50px">
        <h3>用戶顯示界面</h3>
    </div>
    <div class="center" style="width: 800px;height: auto;">
        <table border="1">
            <tr>
                <th>用戶編號</th>
                <th>用戶帳戶</th>
                <th>用戶密碼</th>
                <th>真實名字</th>
                <th>用戶類型</th>
                <th>用戶操做</th>
            </tr>
            <tr>
               <%
                   //實例化接口
                   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":"管理員" %>
                        </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() %>">刪除</a>
                        </td>
                    </tr>
                <%
                   }
                %>
            </tr>
            <tr>
                <td colspan="6" align="center">
                    <a href="./add.jsp">用戶添加</a>
                </td>
            </tr>
        </table>
    </div>
    
  </body>
</html>

8.編寫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 {

    //解析請求方法
    public void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        
        System.out.println("用戶展現界面：com.mart.controller.show");
        //獲取用戶列表
        UserDao udi = new UserDaoImpl();
        List<User> uList = udi.FindAllUser();
        //傳遞用戶列表到前斷
        //此處用session則服務器過載
        request.setAttribute("uList", uList);
        //轉到顯示界面
        //不能重定向，會丟失數據
        response.sendRedirect("user/show.jsp");
        
    }

    //響應請求方法
    public void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        /**
         * get和post行爲相同時，直接設置內部調用便可
         */
        this.doGet(request, response);
    }

}

8.在web.xml裏註冊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>淘寶商城servlet-xml配置</display-name>
  <servlet>
    <description>這是個人用戶顯示界面，顯示所有用戶</description>
    <display-name>user_show</display-name>
    <servlet-name>ShowAction</servlet-name>
    <servlet-class>com.mart.controller.ShowAction</servlet-class>
  </servlet>
  <servlet>
    <description>這是個人用戶添加界面</description>
    <display-name>user_add</display-name>
    <servlet-name>AddAction</servlet-name>
    <servlet-class>com.mart.controller.AddAction</servlet-class>
  </servlet>
  <servlet>
    <description>這是個人用戶刪除界面</description>
    <display-name>user_delete</display-name>
    <servlet-name>DeleteAction</servlet-name>
    <servlet-class>com.mart.controller.DeleteAction</servlet-class>
  </servlet>
  <servlet>
    <description>這是個人用戶更新界面</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>