- _nosay
JDBC实践-编辑功能的实现
2017-12-06 22:12:08
1. 建立EditUserServlet文件,文件内容如下
package com.ungly.servlet;
import com.ungly.bean.User;
import com.ungly.service.ListService;
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 java.io.IOException;
import java.io.PrintWriter;
@WebServlet(name = "EditUserServlet",urlPatterns = "/editUser")
public class EditUserServlet extends HttpServlet {
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8"); //设置编码
String id = request.getParameter("id");
String username = request.getParameter("username");
ListService listService = new ListService();
boolean status = listService.editUser(id, username);
if(status)
{
response.sendRedirect("/List");
}else{
response.setContentType("text/html;charset=utf-8;");
PrintWriter writer = response.getWriter();
writer.write("编辑失败");
}
}
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("UTF-8"); //设置编码
String id = request.getParameter("id"); //接收id参数
ListService listService = new ListService();
User user = listService.showUser(id);
if(user != null)
{
request.setAttribute("user",user);
request.getRequestDispatcher("/WEB-INF/jsp/front/editUser.jsp").forward(request,response);
}else{
}
}
}
2. 在UserDao.java文件中,添加showUser和editUser方法,内容如下
public User showUser(Integer id)
{
User user = new User();
String sql = "SELECT id,username FROM user where id =?";
try {
this.preparedStatement = this.conn.prepareStatement(sql);
this.preparedStatement.setInt(1,id);
ResultSet resultSet = this.preparedStatement.executeQuery();
while (resultSet.next())
{
user.setId(resultSet.getString("id"));
user.setUsername(resultSet.getString("username"));
}
} catch (SQLException e) {
e.printStackTrace();
}
return user;
}
public boolean editUser(Integer id,String username)
{
if(id>0)
{
try {
String sql = "UPDATE user SET username=? WHERE id =?";
this.preparedStatement = this.conn.prepareStatement(sql);
this.preparedStatement.setString(1,username);
this.preparedStatement.setInt(2,id);
int i = this.preparedStatement.executeUpdate();
if(i>0)
{
this.status = true;
}else{
this.status = false;
}
}catch (SQLException e) {
e.printStackTrace();
}finally {
try {
this.conn.close();
this.preparedStatement.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}else{
this.status = false;
}
return this.status;
}
3. 在LisetService文件中添加showUser和editUser方法,内容如下
public User showUser(String id)
{
return this.userDao.showUser(Integer.valueOf(id));
}
public boolean editUser(String id,String username)
{
return this.userDao.editUser(Integer.valueOf(id),username);
}
4. 添加editUser.jsp文件,内容如下
<%--
Created by IntelliJ IDEA.
User: nosay
Date: 17-12-5
Time: 下午3:31
To change this template use File | Settings | File Templates.
--%>
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<html>
<head>
<title>Title</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<link href="https://cdn.bootcss.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet">
</head>
<body>
<div class="container">
<div class="row clearfix">
<div class="col-md-12 column">
<form role="form" method="post" action="/editUser">
<div class="form-group">
<label for="username">用户名</label><input class="form-control" name="username" value="${requestScope.user.username}" id="username" type="username" />
<input type="hidden" name="id" value="${requestScope.user.id}" />
</div>
<button type="submit" class="btn btn-default">Submit</button>
</form>
</div>
</div>
</div>
</body>
</html>
这样实现了所有CURD功能,很简单,算是一个入门的项目吧.
相应的练习项目地址:
阿里云代码托管