创建maven项目 配置Tomcat 这些都不细说了
因为要连接数据库所以一定要在maven项目下的xml文件下配置数据库的jar包依赖
<dependency>
<groupId>mysql</groupId>
<artifactId>mysql-connector-java</artifactId>
<version>8.0.28</version>
</dependency>
这个千万不要忘了 重重之重
package com.li.Servlet.blit;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
public class JDBC {
private static String url = null;
private static String name = null;
private static String password = null;
static {
try {
Class.forName ( "com.mysql.cj.jdbc.Driver" );
} catch (Exception e) {
e.printStackTrace ( );
}
url = "jdbc:mysql://localhost:3306/zhiqingli?useUnicode=true&characterEncoding=utf8&useSSL=true";
name = "root";
password = "root";
}
public static Connection getConn() throws Exception {
return DriverManager.getConnection ( url, name, password );
}
public static void release(Connection conn, PreparedStatement pst, ResultSet res) {
try {
if (res != null) {
res.close ( );
}
if (pst != null) {
pst.close ( );
}
if (conn != null) {
conn.close ( );
}
} catch (Exception e) {
e.printStackTrace ( );
}
}
}
这个类可以直接复制使用，但要改成自己的数据库名字
登陆页面
<%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<body>
<form action="${pageContext.request.contextPath}/test" method="get">
<h3>账号：<input type="text" name="account"></h3>
<h3>密码：<input type="password" name="paw"></h3>
<h3><input type="submit" value="登陆"><a href="Register.jsp" rel="external nofollow" target="_blank">注册</a></h3>
</form>
</body>
</html><%@ page contentType="text/html;charset=UTF-8" language="java" %>
<html>
<head>
<title>注册</title>
</head>
<body>
<form action="${pageContext.request.contextPath}/res" method="post">
<h3>账号：<input type="text" placeholder="请输入注册的账号" name="number"></h3>
<h3>密码：<input type="password" placeholder="请输入注册的密码" name="word" id="one"></h3>
<h3>确认密码：<input type="password" placeholder="确认一遍密码" name="u" id="two"></h3>
<input type="submit" value="提交" οnclick="show()">
</form>
<Script>
function show(){
var one = document.getElementById("one").value;
var two = document.getElementById("two").value;
if (one === two){
alert("注册成功");
window.open("index.jsp")
}else {
alert("两次输入的密码不一致");
}
}
</Script>
</body>
</html>
<%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>成功页面</title> </head> <body> <h1>登陆成功，感谢使用</h1> </body> </html> <%@ page contentType="text/html;charset=UTF-8" language="java" %> <html> <head> <title>失败页面</title> </head> <body> <h1>登陆失败，账号密码找不到或者错误</h1> </body> </html>
工具人上线
//登陆使用的方法
Connection conn = null;
PreparedStatement pst = null;
ResultSet res = null;
boolean isQ;
public boolean Select(String username,String paw) {
try {
conn = JDBC.getConn ( );
String sql = "SELECT * FROM `username` where `name`=? and `password`=?";
pst = conn.prepareStatement (sql);
pst.setObject ( 1,username );
pst.setObject ( 2,paw );
res = pst.executeQuery ( );
if (res.next ()){
isQ = true;
System.out.println (res.getObject ( "name" )+" "+res.getObject ( "password" ));
System.out.println ("登陆成功");
}else {
isQ = false;
System.out.println ("登陆失败");
}
}catch (Exception e){
e.printStackTrace ();
}finally {
JDBC.release ( conn,pst,res );
}
return isQ;
}
//注册用的方法
public void addUser(String name,String paw){
try {
conn = JDBC.getConn ( );
String sql = "insert into `username`(`name`,`password`) values (?,?)";
pst = conn.prepareStatement ( sql );
pst.setObject ( 1,name );
pst.setObject ( 2,paw );
int i = pst.executeUpdate ( );
if (i>0){
System.out.println ("添加成功");
}
}catch (Exception e){
e.printStackTrace ();
}finally {
JDBC.release ( conn,pst,res );
}
}
package com.li.Servlet.test;
import com.li.Servlet.blit.Way;
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 index extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String account = req.getParameter ( "account" );
String paw = req.getParameter ( "paw" );
Way way = new Way ();
if (way.Select ( account,paw )){
resp.sendRedirect ( "/s4/true.jsp" );
}else {
resp.sendRedirect ( "/s4/false.jsp" );
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet ( req, resp );
}
}
package com.li.Servlet.test;
import com.li.Servlet.blit.Way;
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 index02 extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
String number = req.getParameter ( "number" );
String word = req.getParameter ( "word" );
String u = req.getParameter ( "u" );
if (word.equals ( u )){
Way way = new Way ( );
way.addUser ( number,word );
}else {
//当两次密码不一致的时候浏览器响应给用户当前注册的页面
resp.sendRedirect ( "/s4/Register.jsp" );
}
}
@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
doGet ( req, resp );
}
}
<!--登陆-->
<servlet>
<servlet-name>test</servlet-name>
<servlet-class>com.li.Servlet.test.index</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>test</servlet-name>
<url-pattern>/test</url-pattern>
</servlet-mapping>
<!--注册-->
<servlet>
<servlet-name>res</servlet-name>
<servlet-class>com.li.Servlet.test.index02</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>res</servlet-name>
<url-pattern>/res</url-pattern>
</servlet-mapping>
这个就是用户输入的账号和密码看看数据库里有没有，有的话就重定向到成功或这失败的页面，相当于浏览器响应给用户的请求结果
相当于就是往数据库里面添加一个账号或者密码然返回到登陆页面
这里我在注册类面没有用到重定向，而是在注册的jsp页面里判断之后跳转到登陆页面
注意：这里为什么没在注册类里面用重定向
因为使用重定向之后就直接返回了登陆类运行的结果
