java web页面增删改查_javaweb增删改查-优快云博客

本文详细介绍了一个Java Web项目的用户增删改查功能实现，包括添加、删除、编辑和更新用户的Servlet代码，以及相应的web.xml配置。通过示例代码展示了如何使用HttpServletRequest和HttpServletResponse进行前后端交互。

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package service;

import Bean.User;
import dao.UserDAO;

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 AddUser extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        //String id = req.getParameter("id");
        String name = req.getParameter("name");
        String pwd = req.getParameter("pwd");
        String sex = req.getParameter("sex");
        String home = req.getParameter("home");
        String info = req.getParameter("info");
        User user = new User();
        //user.setId(Integer.parseInt(id));
        user.setName(name);
        user.setPwd(pwd);
        user.setSex(sex);
        user.setHome(home);
        user.setInfo(info);

        new UserDAO().add(user);
        resp.sendRedirect("/user");
    }
}

package service;

import dao.UserDAO;

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 {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        String id = req.getParameter("id");

        new UserDAO().delete(Integer.parseInt(id));

        resp.sendRedirect("/user");
    }
}

package service;

import Bean.User;
import dao.UserDAO;

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 EditUserServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        String id = req.getParameter("id");
        User user = new UserDAO().get(Integer.parseInt(id));

        StringBuffer sb = new StringBuffer();
        resp.setContentType("text/html; charset=UTF-8");
        sb.append("<!DOCTYPE html>");
        sb.append("<form action='updateUser' method='post'><br>");
//        sb.append("编号： <input type='text' name='name' value='%d'><br>");
        sb.append("名字： <input type='text' name='name' value='%s'><br>");
        sb.append("密码： <input type='text' name='pwd' value='%s'><br>");
        sb.append("性别： <input type='text' name='sex' value='%s'><br>");
        sb.append("home： <input type='text' name='home' value='%s'><br>");
        sb.append("info： <input type='text' name='info' value='%s'><br>");
        sb.append("<input type='hidden' name='id' value='%d'>");
        sb.append("<input type='submit' value='更新'>");
        sb.append("</form>");

        String format = String.format(sb.toString(), user.getName(), user.getPwd(),
                user.getSex(), user.getHome(), user.getInfo(), user.getId());

        resp.getWriter().write(format);
    }
}

package service;

import Bean.User;
import dao.UserDAO;

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 UpdateUserServlet extends HttpServlet {
    @Override
    protected void service(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        req.setCharacterEncoding("UTF-8");
        User user = new User();
        user.setId(Integer.parseInt(req.getParameter("id")));
        user.setName(req.getParameter("name"));
        user.setPwd(req.getParameter("pwd"));
        user.setSex(req.getParameter("sex"));
        user.setHome(req.getParameter("home"));
        user.setInfo(req.getParameter("info"));
        new UserDAO().update(user);

        resp.sendRedirect("/user");
    }
}

web.xml配置

<?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>UserServlet</servlet-name>
        <servlet-class>service.UserServlet</servlet-class>
    </servlet>
    
    <servlet>
        <servlet-name>AddUser</servlet-name>
        <servlet-class>service.AddUser</servlet-class>
    </servlet>
    
    <servlet>
        <servlet-name>DeleteServlet</servlet-name>
        <servlet-class>service.DeleteServlet</servlet-class>
    </servlet>
    <servlet>
        <servlet-name>EditServlet</servlet-name>
        <servlet-class>service.EditUserServlet</servlet-class>
    </servlet>
    
    <servlet>
        <servlet-name>UpdateUserServlet</servlet-name>
        <servlet-class>service.UpdateUserServlet</servlet-class>
    </servlet>
    
    <servlet-mapping>
        <servlet-name>EditServlet</servlet-name>
        <url-pattern>/editUser</url-pattern>
    </servlet-mapping>
    
    <servlet-mapping>
        <servlet-name>UpdateUserServlet</servlet-name>
        <url-pattern>/updateUser</url-pattern>
    </servlet-mapping>
    
    <servlet-mapping>
        <servlet-name>DeleteServlet</servlet-name>
        <url-pattern>/deleteUser</url-pattern>
    </servlet-mapping>
    
    <servlet-mapping>
        <servlet-name>UserServlet</servlet-name>
        <url-pattern>/user</url-pattern>
    </servlet-mapping>
    
    <servlet-mapping>
        <servlet-name>AddUser</servlet-name>
        <url-pattern>/addUser</url-pattern>
    </servlet-mapping>
</web-app>

页面详情：