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🍖🍖🍖
🍖🍖🍖🍖 作者 : 不良使
🍖🍖🍖🍖🍖 潜力创作新星 华为云享专家
🍖🍖🍖🍖🍖🍖 博客记录学习的思路,项目和错误,寻找志同道合的朋友
🍖🍖🍖🍖🍖🍖🍖 如果觉得有帮助记得一键三连 ┗|`O′|┛ 嗷~~
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💦💦注册登录
🍄🍄注册
package com.bjpowernode.javaweb.servlet;
import com.bjpowernode.javaweb.utils.DButil;
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 java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.SQLException;
@WebServlet(name = "register", value = "/register")
public class Register extends HttpServlet {
@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doPost(request,response);
}
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String Myname = request.getParameter("registerName");
String Mypassword =request.getParameter("registerPwd");
response.setContentType("text/html");
response.setCharacterEncoding("GBK");
Connection conn = null;
PreparedStatement stmt = null;
try {
//注册驱动(作用:告诉Java程序,即将要连接的哪个品牌的数据库)
Class.forName("com.mysql.jdbc.Driver");
//获取连接(表示JVM的进程和数据库进程之间的通道打开了,这属于进程之间的通信,重量级的,使用完之后一定要关闭)
String url = "jdbc:mysql://127.0.0.1:3306/book";
String user = "root";
String password = "123456";
conn = DriverManager.getConnection(url,user,password);
//获取数据库操作对象(专门(Statement专门执行sql语句的)
stmt = conn.prepareStatement("INSERT INTO user VALUES (?,?)");
stmt.setString(1,Myname);
stmt.setString(2,Mypassword);
int count = stmt.executeUpdate();
if(count==1){
PrintWriter out = response.getWriter();
out.println("<script>");
out.println("alert('Registered successfully');");
out.println("location.href='index.html'");//跳转到用户列表页面
out.println("</script>");
}else{
response.getWriter().print("注册失败");
}
// System.out.println(count == 1 ? "保存成功" : "保存失败");
} catch (ClassNotFoundException e) {
e.printStackTrace();
} catch (SQLException e) {
e.printStackTrace();
} finally {
DButil.close(conn,stmt,null);
}
}
}
🍄🍄登录
package com.bjpowernode.javaweb.servlet;
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 java.io.IOException;
import java.io.PrintWriter;
import java.util.Map;
@WebServlet(name = "Login", value = "/Login")
public class Login extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
PrintWriter out = response.getWriter();
String username = request.getParameter("userName");
String password = request.getParameter("userPwd");
Map<String,String> map = Mysql.user();
response.setContentType("text/html");
response.setCharacterEncoding("GBK");
if(map.containsKey(username)) {
System.out.println("进入if判断循环了"); //TODO 进入循环了
String PWD = map.get(username);
System.out.println(PWD);//TODO 有值
if (PWD.equals("admin")) {
if (password.equals("admin")){
out.println("<script>");
out.println("alert('Log in successfully');");
out.println("location.href='Take_01'");//跳转到管理员列表页面
out.println("</script>");
}
else{
out.println("<script>");
out.println("alert('Dear, the account password is incorrect, please input it again');");
out.println("location.href='index.html'");//跳转到用户列表页面
out.println("</script>");
}
}
else if(PWD.equals(password)){
out.println("<script>");
out.println("alert('Log in successfully');");
out.println("location.href='Take_02'");//跳转到用户列表页面
out.println("</script>");
}
else{
out.println("<script>");
out.println("alert('Dear, the account password is incorrect, please input it again');");
out.println("location.href='index.html'");//跳转到用户列表页面
out.println("</script>");
// System.out.println("美猴王");
// response.getWriter().println("齐天大圣");
}
}
else{
out.println("<script>");
out.println("alert('This account is not registered, dear, please register first!!!');");
out.println("location.href='index.html'");//跳转到用户列表页面
out.println("</script>");
}
}
}
💦💦留言板模块
🐱👓🐱👓留言板
🐱👓🐱👓热搜榜
详细步骤和代码见此篇文章 结巴分词之热评处理
🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴🛴
💦💦查询&&搜索
package com.bjpowernode.javaweb.servlet;
import com.bipowernode.pojo.Olypic;
import com.bjpowernode.javaweb.utils.DButil;
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 java.io.IOException;
import java.io.PrintWriter;
import java.sql.*;
import java.util.ArrayList;
import java.util.List;
@WebServlet(name = "select",value = "/select")
public class Select extends HttpServlet {
@Override
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
request.setCharacterEncoding("UTF-8");
String name = request.getParameter("select_name");
System.out.println(name);
//连接数据库
Connection conn = null;
PreparedStatement ps = null;
ResultSet rs = null;
List<Olypic> olypicList=new ArrayList<>();
try {
Class.forName("com.mysql.jdbc.Driver");
//获取连接
conn = DriverManager.getConnection("jdbc:mysql://localhost:3306/mofa", "root", "123456");
String sql = "select * from medals_table where Country=?";
//编译sql语句
ps = conn.prepareStatement(sql);
//赋值 第一个问好赋值 country 国家名称
ps.setString(1, name);
//查询返回结果集 这个结果集只有一条记录 ,国家名称是主键 , 故只有一条数据
rs = ps.executeQuery();
if (rs.next()) {
String country = rs.getString("Country");
String Glod = rs.getString("Glod_num");
String Silver = rs.getString("Silver_num");
String Copper = rs.getString("Copper_num");
String id=rs.getString("id");
String logo=rs.getString("logo");
System.out.println("这是数据");
System.out.println(country);
System.out.println("Glod");
// String Sum=rs.getString("Sum");
int G = Integer.valueOf(Glod).intValue();
int S = Integer.valueOf(Silver).intValue();
int C = Integer.valueOf(Copper).intValue();
int A=G+S+C;
String Sum=String.valueOf(A);
//将数据封装程Java对象
Olypic olpic=new Olypic();
olpic.setCountry(country);
olpic.setGlod_num(Glod);
olpic.setSilver_num(Silver);
olpic.setCopper_num(Copper);
olpic.setId(id);
olpic.setSum(Sum);
olpic.setLogo(logo);
// TODO 将数据放入上面定义好的容器
olypicList.add(olpic);
}
} catch (SQLException e) {
e.printStackTrace();
} catch (ClassNotFoundException e) {
e.printStackTrace();
} finally {
DButil.close(conn, ps, rs);
}
request.setAttribute("olypicList",olypicList);
request.getRequestDispatcher("./take_03.jsp").forward(request,response);
}
}
💦💦增删改查
详细代码见 Java/JavaWeb 连接数据库完成增删改查
完整项目见:JavaSE项目
因为有些同学找我要数据库文件,就把他放入这里数据库数据
觉得有用的可以给个三连,关注一波!!!带你了解更多的Java小项目