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jsp+servlet+javabean开发web项目

2020-08-18 22:50 946 查看

一、运行原理:

  项目依赖包:jdbc数据库包

  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() 

二、开发步骤: 

  1、新建web项目

 

  2、新建实体类  User.java

1 package com.mart.bean;
2
3 public class User {
4
5     //属性
6     private Integer id;
7     private String uname;
8     private String upass;
9     private String tname;
10     private String utype;
11     //属性访问
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     //构造
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     //更新操作改善,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、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="width: 800px;height: 50px">
<h3>用户显示界面</h3>
</div>
<div class="center" style="width: 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);
}

}

    9、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>

 

 转载于:https://www.cnblogs.com/hackxiyu/p/7073850.html

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