手机网站模板更换方法,新闻客户端网站开发,wordpress 分词插件,centos 7 安装wordpress一、需求
在Servlet中可以使用JDBC技术访问数据库#xff0c;常见功能如下#xff1a;
查询DB数据#xff0c;然后生成显示页面#xff0c;例如#xff1a;列表显示功能。接收请求参数#xff0c;然后对DB操作#xff0c;例如#xff1a;注册、登录、修改密码等功能。…一、需求
在Servlet中可以使用JDBC技术访问数据库常见功能如下
查询DB数据然后生成显示页面例如列表显示功能。接收请求参数然后对DB操作例如注册、登录、修改密码等功能。
二、代码演示
1、编写注册界面 创建空工程在工程中创建javaEE模块 配置中设置tomcat的部署 编写register界面 !DOCTYPE html
html langen
headmeta charsetUTF-8title简单注册界面/title
/head
bodyform actionregister methodpost用户名input typetext nameuserName/br密码input typetext namepasswordbrinput typesubmit value注册/form/body
/html2、编写Servlet 获取注册信息
编写servlet
RegisterServlet javapackage com.example.register_demo01;import javax.servlet.*;import javax.servlet.http.*;import java.io.IOException;public class RegisterServlet extends HttpServlet {Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1、获取请求的用户名和密码String userName request.getParameter(userName);System.out.println(获取到的用户名为 userName);String password request.getParameter(password);System.out.println(获取到的密码为 password);}}web.xml ?xml version1.0 encodingUTF-8?
web-app xmlnshttp://xmlns.jcp.org/xml/ns/javaeexmlns:xsihttp://www.w3.org/2001/XMLSchema-instancexsi:schemaLocationhttp://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsdversion4.0servletservlet-nameRegisterServlet/servlet-nameservlet-classcom.example.register_demo01.RegisterServlet/servlet-class/servletservlet-mappingservlet-nameRegisterServlet/servlet-nameurl-pattern/register/url-pattern/servlet-mapping
/web-app部署测试 运行tomcat 访问注册界面发送注册请求tomcat获取注册信息
3、 创建原始User类
package com.example.register_demo01.pojo;public class User {private int id;private String userName;private String password;public User(){}public User(String userName, String password) {this.userName userName;this.password password;}public int getId() {return id;}public void setId(int id) {this.id id;}public String getUserName() {return userName;}public void setUserName(String userName) {this.userName userName;}public String getPassword() {return password;}public void setPassword(String password) {this.password password;}Overridepublic String toString() {return User{ id id , userName userName \ , password password \ };}
}4、创建数据库 5、创建DbUtil使用jdbc控制数据库
代码
package com.example.register_demo01.utils;import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;public class DbUtil {private static String jdbcName;private static String dbUrl;private static String dbUserName;private static String dbPassword;//静态初始化操作static {jdbcName com.mysql.jdbc.Driver;dbUrl jdbc:mysql://localhost:3306/db_web;dbUserName root;dbPassword root;try {Class.forName(jdbcName);} catch (ClassNotFoundException e) {e.printStackTrace();}}public static Connection getConnection() throws SQLException {Connection connection DriverManager.getConnection(dbUrl, dbUserName, dbPassword);return connection;}public static void closeConnection(Connection con) throws SQLException {if (null ! con){con.close();}}}6、编写UserDao将User对象存储到数据库
代码
package com.example.register_demo01.dao;import com.example.register_demo01.pojo.User;
import com.example.register_demo01.utils.DbUtil;import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;public class UserDao {public int createUser(User user) {Connection connection null;PreparedStatement preparedStatement null;try {//1、获取连接Connection connection1 DbUtil.getConnection();//2、准备sqlString sql insert into t_user values(null, ?, ?);//3、获取PreparedStatementpreparedStatement connection.prepareStatement(sql);//4、向问号位置设置数据preparedStatement.setString(1, user.getUserName());preparedStatement.setString(2, user.getPassword());//5、执行sqlint row preparedStatement.executeUpdate();return row;} catch (SQLException throwables) {throwables.printStackTrace();}finally {//6、关闭资源try {DbUtil.closeConnection(connection);if(preparedStatement ! null){preparedStatement.close();}} catch (SQLException throwables) {throwables.printStackTrace();}}return -1;//执行失败}
}7、修改Servlet添加保存进数据库的操作 代码 package com.example.register_demo01;import com.example.register_demo01.dao.UserDao;
import com.example.register_demo01.pojo.User;import javax.servlet.*;
import javax.servlet.http.*;
import java.io.IOException;
import java.io.PrintWriter;public class RegisterServlet extends HttpServlet {Overrideprotected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {this.doPost(request, response);}Overrideprotected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {//1、获取请求的用户名和密码String userName request.getParameter(userName);System.out.println(获取到的用户名为 userName);String password request.getParameter(password);System.out.println(获取到的密码为 password);//2、封装user信息将信息保存到数据库User user new User(userName, password);UserDao userDao new UserDao();int res userDao.createUser(user);//3、将处理结果响应到浏览器response.setContentType(text/html;charsetutf-8);PrintWriter writer response.getWriter();if (1 res){System.out.println(注册成功);writer.write(h1注册成功/h1);}else {System.out.println(注册失败);writer.write(h1注册失败/h1);}writer.close();}
}测试结果
