2代码样例（注册登录）

代码样例：
注册RegServlet

package com.neuedu.servlet;

import java.io.IOException;
import java.io.PrintWriter;

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 com.neuedu.model.service.IUserService;
import com.neuedu.model.service.impl.UserServiceImpl;
import com.neuedu.pojo.User;

/**
 * Servlet implementation class RegServlet
 */
@WebServlet("/regServlet")
public class RegServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
   
/**
 * @see HttpServlet#HttpServlet()
 */
public RegServlet() {
super();
// TODO Auto-generated constructor stub
}

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request,response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    request.setCharacterEncoding("utf-8");
    response.setCharacterEncoding("utf-8");
    //接收用户输入
        String name=request.getParameter("uname");
        System.out.println(name);
        String password=request.getParameter("paw");
        String repassword=request.getParameter("paw1");
        String email=request.getParameter("email");
        String idCard=request.getParameter("idcard");
        String[] cookieFlag=request.getParameterValues("CookieYN");
        System.out.println(cookieFlag);
        //打包user
        User user=new User();
        user.setUserName(name);
        user.setUserPwd(password);
        user.setUserPwd1(repassword);
        user.setEmail(email);
        user.setIdCard(idCard);
        //调用service进行处理
        IUserService userService=new UserServiceImpl();
        int i=userService.addUser(user);
        //返回处理结果
        response.setContentType("text/html;charset=utf-8");
        PrintWriter out=response.getWriter();
        if(i>0){
            out.println("success");
        }else{
            out.println("failure");
        }
    }

}

登录LoginServlet

package com.neuedu.servlet;

import java.io.IOException;

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 com.neuedu.model.service.IUserService;
import com.neuedu.model.service.impl.UserServiceImpl;
import com.neuedu.pojo.User;

/**
 * Servlet implementation class LoginServlet
 */
@WebServlet("/loginServlet")
public class LoginServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
   
/**
 * @see HttpServlet#HttpServlet()
 */
public LoginServlet() {
super();
// TODO Auto-generated constructor stub
}

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        doPost(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
                
        request.setCharacterEncoding("utf-8");
        response.setCharacterEncoding("utf-8");
        //获取页面输入的用户名和密码
        String username=request.getParameter("username");
        String password=request.getParameter("password");
        User user=new User();
        user.setUserName(username);
        user.setUserPwd(password);
        IUserService service=new UserServiceImpl();
        User dbuser=service.getUser(user);
        if(dbuser!=null){//如果数据库里有此用户
            System.out.println("回首页");
            //判断是普通用户还是管理员
            //如果是普通用户，进首页
            if(dbuser.getPower()==0){
                //index.html
                response.sendRedirect(request.getContextPath()+"/user/index.html");
            }else{
                //如果是管理员，进管理员首页
                //admin/index.html
                response.sendRedirect(request.getContextPath()+"/admin/index.html");
            }
            
        }else{
        //回登录页重新登录
        request.getRequestDispatcher("/login.html").forward(request, response);
    }
    }
}

接口
public interface IUserService {

    int addUser(User user);

    User getUser(User user);

}

public interface IUserDao {


public int add(User user);

User getUser(User user);

}

相关service

package com.ne
uedu.model.service.impl;

import com.neuedu.model.dao.IUserDao;
import com.neuedu.model.dao.impl.UserDaoImpl;
import com.neuedu.model.service.IUserService;
import com.neuedu.pojo.User;

public class UserServiceImpl implements IUserService {
    IUserDao userDao=new UserDaoImpl();

    @Override
    public int addUser(User user) {
        int i=0;
        
        //验证合法性
        //比如用户名是否重复
        //两次密码是否一致。。。。。。
        //如果验证通过，就存库
        User dbuser=userDao.getUser(user);
        //调用dao存库
        if(dbuser!=null){//已经被注册过了
            return 0;
        }else{
            i=userDao.add(user);
        }
        
        return i;
    }

    @Override
    public User getUser(User user) {
        return userDao.getUser(user);
    }

}

dao:

package com.neuedu.model.dao.impl;

import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;

import com.neuedu.model.dao.IUserDao;
import com.neuedu.pojo.User;
import com.neuedu.utils.DBUtil;

public class UserDaoImpl implements IUserDao {
    PreparedStatement ps=null;
    Connection conn=null;
    ResultSet rs=null;
    @Override
    public int add(User user) { 
        int i=0;
        try {
            conn=DBUtil.getConnection();
            ps=conn.prepareStatement("INSERT INTO t_user VALUES(NULL,?,?,?,?,?)");
            ps.setString(1,user.getUserName());
            ps.setString(2,user.getUserPwd());
            ps.setString(3,user.getEmail());
            ps.setString(4,user.getIdCard());
            ps.setInt(5, user.getPower());
            i=ps.executeUpdate();
        } catch (SQLException e) {
            e.printStackTrace();
        }
        
        return i;
    }
    @Override
    public User getUser(User user) {
        User dbuser=null;
        conn=DBUtil.getConnection();
        try {
            ps=conn.prepareStatement("select * from t_user where user_name=? and user_pwd=?");
            ps.setString(1, user.getUserName());
            ps.setString(2, user.getUserPwd());
            rs=ps.executeQuery();
            if(rs.next()){//如果有该用户
                dbuser=new User();
                dbuser.setId(rs.getInt("user_id"));
                dbuser.setUserName(rs.getString("user_name"));
                dbuser.setUserPwd(rs.getString("user_pwd"));
                dbuser.setEmail(rs.getString("user_email"));
                dbuser.setIdCard(rs.getString("user_idcard"));
                dbuser.setPower(rs.getInt("user_power"));
            }
        } catch (SQLException e) {

            e.printStackTrace();
        }
        return dbuser;
    }
  }

作者：wqjcarnation
链接：https://www.jianshu.com/p/e1e458b75001
来源：简书
简书著作权归作者所有，任何形式的转载都请联系作者获得授权并注明出处。