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");
}
} }

今日份Java的更多相关文章

  1. Spark案例分析

    一.需求:计算网页访问量前三名 import org.apache.spark.rdd.RDD import org.apache.spark.{SparkConf, SparkContext} /* ...

  2. java日期操作大全

    摘自(http://www.blogjava.net/i369/articles/83483.html) java日期操作 大全 先来一个:  取得指定月份的第一天与取得指定月份的最后一天  http ...

  3. java实现获取当前年月日 小时 分钟 秒 毫秒

    java代码实现如下 view source print?     /**      * 英文简写(默认)如:2010-12-01      */     public static String F ...

  4. Java基础——JDBC

    今天学习的内容是:JDBC 通常jdbc连接分6步: 1)注册驱动: 2)建立连接: 3)创建Statement: 4)执行sql 语句: 5)处理结果集(若sql 语句为查询语句): 6)关闭连接. ...

  5. Java时间日期格式转换Date转String和String转Date

    Java时间格式转换大全 import java.text.*; import java.util.Calendar; public class VeDate { /** * 获取现在时间 * * @ ...

  6. java实现获取当前年、月、日 、小时 、分钟、 秒、 毫秒

    转载 : https://blog.csdn.net/qq_36652619/article/details/85621020 package com.app.test; import java.te ...

  7. java 和js 时间 格式化(yyyy-MM-dd HH:mm:ss) 以及获取当前时间

    1.js var myDate = new Date(); myDate.getYear(); //获取当前年份(2位) myDate.getFullYear(); //获取完整的年份(4位,1970 ...

  8. java网页日期选择框对应的星期有误

    · 我用java写了个星期查询代码,有的日期对有的日期错,求帮忙看看哪里有问题!! import java.util.*;public class Test1 {public static void ...

  9. 故障重现(内存篇2),JAVA内存不足导致频繁回收和swap引起的性能问题

    背景起因: 记起以前的另一次也是关于内存的调优分享下   有个系统平时运行非常稳定运行(没经历过大并发考验),然而在一次活动后,人数并发一上来后,系统开始卡. 我按经验开始调优,在每个关键步骤的加入如 ...

随机推荐

  1. c++产生非常量引用的初始值必须是左值

    出现这种情况是因为调用函数的形参类型是  T&(T为某一类型),该类型与调用参数值传入不一致,比如函数中形参是int型,而传入实参是double,存在隐式类型转化,系统会自动产生临时变量tem ...

  2. Spring-cloud微服务实战【八】:API网关zuul

      在前面的文章中,我们先后使用了eureka/ribbon/feign/hystrix搭建了一个看似完美的微服务了,那是否还有值得继续优化的地方呢?答案肯定是有的,如果从整个微服务内部来看,基本已经 ...

  3. android实例 listview与sqlite数据绑定

    ListView与Sqlite数据库绑定步骤: 1.将Sqlite数据库的内容查询出来并放入数组列表中,形成ListView的数据源: 2.适配器绑定数据源,显示在ListView item中. 本文 ...

  4. An internal error occurred during: "Launching New_configuration". Path for project must have only on

    在Eclipse中按照如下操作 Project -> Properties -> Run/Debug Settings: 1. select "Launching New_con ...

  5. POJ_3450_KMP

    http://poj.org/problem?id=3450 直接暴力枚举第一行的每一个字串,在下面的字符串中查找就行了,注意不符合就及时break. 然后试了一下strstr,发现效率是KMP的3- ...

  6. Codeforces 1064D Labyrinth(双端队列BFS)

    题意: 给一个图,"*"不可以走,给你一个起点,限制向左走L次,向右走R次,上下不限制,问你最多可以走到多少个格子 思路: BFS,每次将上下走的策略加入队首,左右加入队尾,(相当 ...

  7. 【WPF学习】第四十五章 可视化对象

    前面几章介绍了处理适量适中的图形内容的最佳方法.通过使用几何图形.图画和路径,可以降低2D图形的开销.即使正在使用复杂的具有分层效果的组合形状和渐变画刷,这种方法也仍然能够正常得很好. 然而,这样设计 ...

  8. gridFS-Nginx的安装与使用

    在使用gridFs的nginx模块时,先确认好你的机器上已经安装好了mongo 首先通过git将最新的gridfs的nginx模块下载到本地 git clone https://github.com/ ...

  9. 1138 - Trailing Zeroes (III) 二分

    1138 - Trailing Zeroes (III)   You task is to find minimal natural number N, so that N! contains exa ...

  10. webpack性能优化

    Webpack优化打包速度以及性能优化 1.跟上技术的迭代(Node.Npm.Yarn) 2.在尽可能少的模块上应用loader 3.Plugin尽可能精简并确保可靠 4.resolve参数合理配置 ...