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  • 今日份Java

    package util;
    
    import java.sql.*;
    
    public class DBUtil {
        
        static String url = "jdbc:mysql://localhost:3306/class?useunicuee& characterEncoding=utf8";
        static String username = "root";
        static String password = "root";
        static Connection conn = null;
        static ResultSet rs = null;
        static PreparedStatement ps = null;
        
        public static void init() {
            try {
                Class.forName("com.mysql.jdbc.Driver");
                conn = DriverManager.getConnection(url,username,password);
            }catch(Exception e) {
                System.out.println("init [SQL驱动程序初始化失败!]");
                e.printStackTrace();
            }
        }
        
        public static int addUpdDel(String sql) {
            int i = 0;
            try {
                PreparedStatement ps = conn.prepareStatement(sql);
                i = ps.executeUpdate();
            }catch(SQLException e) {
                System.out.println("sql数据库增删改异常!");
                e.printStackTrace();
            }
            return i;
        }
        
        public static ResultSet selectSql(String sql) {
            try {
                ps = conn.prepareStatement(sql);
                rs = ps.executeQuery(sql);
            }catch(SQLException e) {
                System.out.println("sql数据库查询异常!");
                e.printStackTrace();
            }
            return rs;
        }
        
        public static void closeConn() {
            try {
                conn.close();
            }catch(SQLException e) {
                System.out.println("sql数据库关闭异常!");
                e.printStackTrace();
            }
            
        }
    
    }
    package dao;
    
    import java.util.List;
    import entity.User;
    
    public interface UserDao {
        
        public boolean login(String name,String pwd);//登录
        public boolean register(User user);//注册
        public List<User> getUserAll();//返回用户信息集合
        public boolean delete(int id);//根据id删除用户
        public boolean update(int id,String name,String pwd,String sex,String home,String info);//更新用户信息
    
    }
    package dao;
    
    import java.sql.ResultSet;
    import java.sql.SQLException;
    import java.util.ArrayList;
    import java.util.List;
    
    import entity.User;
    import util.DBUtil;
    
    public class UserDaoImpl implements UserDao{
        public boolean register(User user) {
            boolean flag = false;
            DBUtil.init();
            int i = DBUtil.addUpdDel("insert into user(name,pwd,sex,home,info)" +
                             "values('"+user.getName()+"','"+user.getPwd()+"','"+user.getSex()+"','"+user.getHome()+"','"+user.getInfo()+"')");
            if(i>0) {
                flag = true;
            }    
            DBUtil.closeConn();
            return flag;
        }
        
        public boolean login(String name,String pwd) {
            boolean flag = false;
            try {
                DBUtil.init();
                ResultSet rs = DBUtil.selectSql("select * from user where name ='"+name+"' and pwd='"+pwd+"'");
                while(rs.next()) {
                    if(rs.getString("name").equals(name)&&rs.getString("pwd").equals(pwd)) {
                        flag = true;
                    }
                }
                DBUtil.closeConn();
            }catch(SQLException e) {
                e.printStackTrace();
            }
            return flag;
        }
        
        public List<User> getUserAll(){
            List<User> list = new ArrayList<User>();
            try {
                DBUtil.init();
                ResultSet rs = DBUtil.selectSql("select * from user");
                while(rs.next()) {
                    User user = new User();
                    user.setId(rs.getInt("id"));
                    user.setName(rs.getString("name"));
                    user.setPwd(rs.getString("pwd"));
                    user.setSex(rs.getString("sex"));
                    user.setHome(rs.getString("home"));
                    user.setInfo(rs.getString("info"));
                    list.add(user);
                }
                DBUtil.closeConn();
                return list;
            }catch(SQLException e) {
                e.printStackTrace();
            }
            return null;
        }
        
        public boolean update(int id,String name,String pwd,String sex,String home,String info) {
            boolean flag = false;
            DBUtil.init();
            String sql = "update user set name ='"+name
                    +"' , pwd ='"+pwd
                    +"' , sex ='"+sex
                    +"' , home ='"+home
                    +"' , info ='"+info+"' where id = "+id;
            int i =DBUtil.addUpdDel(sql);
            if(i>0) {
                flag = true;
            }
            DBUtil.closeConn();
            return flag;
        }
        
        public boolean delete(int id) {
            boolean flag = false;
            DBUtil.init();
            String sql = "delete from user where id="+id;
            int i = DBUtil.addUpdDel(sql);
            if(i>0) {
                flag = true;
            }
            DBUtil.closeConn();
            return flag;
        }
        
    }
    package entity;
    
    public class User {
        
        private int id;
        private String name;
        private String pwd;
        private String sex;
        private String home;
        private String info;
        
        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 getPwd() {
            return pwd;
        }
        public void setPwd(String pwd) {
            this.pwd=pwd;
        }
        public String getSex() {
            return sex;
        }
        public void setSex(String sex) {
            this.sex=sex;
        }
        public String getHome() {
            return home;
        }
        public void setHome(String home) {
            this.home=home;
        }
        public String getInfo() {
            return info;
        }
        public void setInfo(String info) {
            this.info=info;
        }
        
    }
    package servlet;
    
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import dao.UserDao;
    import dao.UserDaoImpl;
    
    public class DeleteServlet extends HttpServlet{
        public void doGet(HttpServletRequest request, HttpServletResponse response)            
                throws ServletException, IOException {        
            doPost(request, response);    
            }    
        public void doPost(HttpServletRequest request, HttpServletResponse response)            
                throws ServletException, IOException {    
            String id = request.getParameter("id");
            int userId = Integer.parseInt(id);
            
            UserDao ud = new UserDaoImpl();
            
            if(ud.delete(userId)) {
                request.setAttribute("xiaoxi", "删除成功");        
                request.getRequestDispatcher("/Searchall").forward(request, response);
            }else {
                response.sendRedirect("index.jsp");
            }
        }
    
    }
    package servlet;
    
    import java.io.IOException;
    //import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    //import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import dao.UserDao;
    import dao.UserDaoImpl;
    
    public class DengLuServlet extends HttpServlet{
        
        public void doGet(HttpServletRequest request,HttpServletResponse response)
                        throws ServletException,IOException {
            doPost(request,response);
        }
        
        public void doPost(HttpServletRequest request,HttpServletResponse response)
                        throws ServletException,IOException {
            String name = request.getParameter("name");
            String pwd = request.getParameter("pwd");
            UserDao ud = new UserDaoImpl();
            
            if(ud.login(name, pwd)) {
                request.setAttribute("xiaoxi", "欢迎用户"+name);
                request.getRequestDispatcher("/success.jsp").forward(request,response);
            }else {
                response.sendRedirect("index.jsp");
            }
        }
    
    }
    package servlet;
    
    import java.util.List;
    import java.io.IOException;
    import java.io.PrintWriter;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import dao.UserDao;
    import dao.UserDaoImpl;
    import entity.User;
    
    public class SearchallServlet extends HttpServlet{
        public void doGet(HttpServletRequest request, HttpServletResponse response)            
                throws ServletException, IOException {        
            doPost(request, response);    
            }    
        public void doPost(HttpServletRequest request, HttpServletResponse response)            
                throws ServletException, IOException {                
            UserDao ud = new UserDaoImpl();        
            List<User> userAll = ud.getUserAll();        
            request.setAttribute("userAll", userAll);        
            request.getRequestDispatcher("/showall.jsp").forward(request, response);    
        }
    }
    package servlet;
    
    import java.io.IOException;
    
    import javax.servlet.ServletException;
    import javax.servlet.http.HttpServlet;
    import javax.servlet.http.HttpServletRequest;
    import javax.servlet.http.HttpServletResponse;
    
    import dao.UserDao;
    import dao.UserDaoImpl;
    import entity.User;
    
    public class ZhuCeServlet extends HttpServlet{
        
        public void doGet(HttpServletRequest request,HttpServletResponse response)
                        throws ServletException,IOException {
            doPost(request,response);
        }
        public void doPost(HttpServletRequest request,HttpServletResponse response)
                        throws ServletException,IOException {
            String name = request.getParameter("name");
            String pwd = request.getParameter("pwd");
            String sex = request.getParameter("sex");
            String home = request.getParameter("home");
            String info = request.getParameter("info");
            
            User user = new User();
            user.setName(name);
            user.setPwd(pwd);
            user.setSex(sex);
            user.setHome(home);
            user.setInfo(info);
            
            UserDao ud = new UserDaoImpl();
            
            if(ud.register(user)) {
                request.setAttribute("username", name);
                request.getRequestDispatcher("/denglu.jsp").forward(request, response);
            }else {
                response.sendRedirect("index.jsp");
            }
        }
    
    }
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  • 原文地址:https://www.cnblogs.com/vvxvv/p/12012227.html
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