【JAVA】Servlet有条理的实现层次分明的注册及注销

前言前期准备导入jar包设置数据库 Codemodel下的User类util下的DBUtil类dao下的UserDao类service下的UserService类servlet下的AddServlet类servlet下的AddServlet类web下的web.xml页面web下的index.jsp页面web下的add.jsp页面web下的delete.jsp页面 效果图

前言

Java项目实习第四次课后作业：实现Tomcat简单注册及注销界面。

前期准备

导入jar包

设置数据库

Code

model下的User类

package com.zr0629.model; public class User { private int id; private String name; private String password; private String age; //按住键盘上的alt + insert键 public int getId() { return id; } public void setId(int id) { this.id = id; } public String getName() { return name; } public void setName(String name) { this.name = name; } public String getPassword() { return password; } public void setPassword(String password) { this.password = password; } public String getAge() { return age; } public void setAge(String age) { this.age = age; } @Override public String toString() { return "User{" + "id=" + id + ", name='" + name + '\'' + ", password='" + password + '\'' + ", age='" + age + '\'' + '}'; } }

util下的DBUtil类

package com.zr0629.util; import java.sql.*; public class DBUtil { public static Connection getConnection() throws ClassNotFoundException, SQLException { Class.forName("com.mysql.jdbc.Driver"); System.out.println("连接数据库"); //创建连接 Connection connection = DriverManager.getConnection("jdbc:mysql://localhost:3306/testtt?useSSL=false&serverTimezone=Asia/Shanghai","root","123456"); return connection; } public static void closeAll(ResultSet rs, Statement stmt,Connection conn) throws SQLException { if(rs!=null){ rs.close(); } if(stmt!=null){ stmt.close(); } if(conn!=null){ conn.close(); } } }

dao下的UserDao类

package com.zr0629.dao; import com.zr0629.model.User; import com.zr0629.util.DBUtil; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.SQLException; import java.util.stream.Stream; public class UserDao { public int add(User user){ Connection connection = null; PreparedStatement pstmt = null; int count = 0; try{ connection = DBUtil.getConnection(); System.out.println("连接成功"); //获取执行sql的Statement对象 pstmt = connection.prepareStatement("insert into user(name,password,age) values (?,?,?)"); pstmt.setString(1,user.getName()); pstmt.setString(2,user.getPassword()); pstmt.setString(3,user.getAge()); //执行sql，获取结果 count = pstmt.executeUpdate(); System.out.println("insert操作：" + count); return count; }catch (Exception e){ e.printStackTrace(); }finally { try { DBUtil.closeAll(null,pstmt,connection); } catch (SQLException e) { e.printStackTrace(); } } return count; } public int delete(User user){ Connection connection = null; PreparedStatement pstmt = null; int count = 0; try{ connection = DBUtil.getConnection(); //获取执行sql的Statement对象 pstmt = connection.prepareStatement("delete from user where name = ? and password = ? and age = ?"); pstmt.setString(1,user.getName()); pstmt.setString(2,user.getPassword()); pstmt.setString(3,user.getAge()); //执行sql，获取结果 count = pstmt.executeUpdate(); System.out.println("delete操作：" + count); return count; }catch (Exception e){ e.printStackTrace(); }finally { try { DBUtil.closeAll(null,pstmt,connection); } catch (SQLException e) { e.printStackTrace(); } } return count; } }

service下的UserService类

package com.zr0629.service; import com.zr0629.dao.UserDao; import com.zr0629.model.User; public class UserService { UserDao userDao = new UserDao(); public int add(User user){ System.out.println("service中add方法被调用"); return userDao.add(user); } public int delete(User user){ System.out.println("service中del方法被调用"); return userDao.delete(user); } }

servlet下的AddServlet类

package com.zr0629.servlet; import com.zr0629.model.User; import com.zr0629.service.UserService; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class AddServlet extends HttpServlet { UserService userService = new UserService(); protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("执行了doPost"); String method = req.getParameter("method"); if(method.equals("save")){ insert(req,resp); } } public void insert(HttpServletRequest req,HttpServletResponse resp) throws ServletException, IOException { User user = new User(); String name = req.getParameter("name"); String password = req.getParameter("password"); String age = req.getParameter("age"); user.setName(name); user.setPassword(password); user.setAge(age); System.out.println(user); int count = userService.add(user); if(count>0){ resp.sendRedirect("/index.jsp"); }else { resp.getWriter().write("failed"); } } }

servlet下的AddServlet类

package com.zr0629.servlet; import com.zr0629.model.User; import com.zr0629.service.UserService; import javax.servlet.ServletException; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import java.io.IOException; public class DeleteServlet extends HttpServlet { UserService userService = new UserService(); protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { System.out.println("执行了doPost"); String method = req.getParameter("method"); if(method.equals("delete")){ delete(req,resp); } } public void delete(HttpServletRequest req,HttpServletResponse resp) throws ServletException, IOException { User user = new User(); String name = req.getParameter("name"); String password = req.getParameter("password"); String age = req.getParameter("age"); user.setName(name); user.setPassword(password); user.setAge(age); System.out.println(user); int count = userService.delete(user); if(count>0){ resp.sendRedirect("/index.jsp"); }else { resp.getWriter().write("failed"); } } }

web下的web.xml页面

<?xml version="1.0" encoding="UTF-8"?> <web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_4_0.xsd" version="4.0"> <servlet> <servlet-name>addservlet</servlet-name> <!--与下方mapping的name保持一致--> <servlet-class>com.zr0629.servlet.AddServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>addservlet</servlet-name> <!--与上方name保持一致--> <url-pattern>/add</url-pattern> </servlet-mapping> <servlet> <servlet-name>deleteServlet</servlet-name> <!--与下方mapping的name保持一致--> <servlet-class>com.zr0629.servlet.DeleteServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>deleteServlet</servlet-name> <!--与上方name保持一致--> <url-pattern>/delete</url-pattern> </servlet-mapping> </web-app>

web下的index.jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>$Title$</title> </head> <body> <h1>登陆</h1> <form action="/login" method="post"> name:<input name="name" type="text"> password:<input name="password" type="password"> <input type="submit" value="login"> </form> <a href="add.jsp">注册</a> <a href="delete.jsp">注销</a> </body> </html>

web下的add.jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>注册</title> </head> <h1>注册</h1> <body> <form action="/add?method=save" method="post"> <!-- 对应AddServlet中的if语句--> name:<input name="name" type="text"> password:<input name="password" type="password"> age:<input name="age" type="text"> <input type="submit" value="注册" > </form> </body> </html>

web下的delete.jsp页面

<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>注销账户</title> </head> <h1>注销</h1> <body> <form action="/delete?method=delete" method="post"> <!-- 对应AddServlet中的if语句--> name:<input name="name" type="text"> password:<input name="password" type="password"> age:<input name="age" type="text"> <input type="submit" value="注销" > </form> </body> </html>

效果图

最开始的user表 运行程序后的开始界面-index,jsp

点击注册超链接 输入未有名称进行注册 注册后的user表 再返回点击注销超链接 输入已有名称进行注销 注销后的user表