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嗨，我正在寫一個程序在Java驗證用戶，如果登錄用戶是管理員，他可以添加另一個用戶從註冊表單到數據庫。但是當我要註冊某人並按下注冊按鈕時，它會向我顯示此錯誤。 任何人都可以幫我解決這個問題嗎？ 這裏是我的代碼：爲什麼沒有這個代碼wrking？HTTP狀態404 - 沒有在jsp和servlet上找到
index.jsp:
3210
的welcome.jsp：
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Welcome <%=session.getAttribute("name")%></title>
</head>
<body>
<h3>Register form</h3>
<form method="post" action="Register.jsp">
Name:<input type="text" name="name" /><br/>
Password:<input type="text" name="pass" /><br/>
Email:<input type="text" name="email" /><br/>
<input type="submit" value="register" />
</form>
</body>
</html>NewFile.jsp：
<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
pageEncoding="ISO-8859-1"%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Welcome <%=session.getAttribute("name")%></title>
</head>
<body>
<h3>Login successful!!! user</h3>
<h4>
Hello,
<%=session.getAttribute("name")%></h4>
</body>
</html>LoginCheck.java：
package com.example.saeid;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
public class LoginCheck {
static Boolean isadmin = false;
public static boolean validate(String name, int pass) {
boolean isValid = false;
Connection conn = null;
ResultSet rs = null;
String db_userName = "root";
String db_Password = "uyhgbv098";
String db_Name = "my_demo_database";
String driver = "com.mysql.jdbc.Driver";
String url = "jdbc:mysql://localhost:3306/";
PreparedStatement ps = null;
try {
Class.forName(driver);
conn = DriverManager.getConnection(url+db_Name,db_userName,db_Password);
ps =conn.prepareStatement
("select * from user_account where username=? and password=?");
ps.setString(1, name);
ps.setInt(2, pass);
rs = ps.executeQuery();
if(rs.next()) {
isValid = true;
isadmin = rs.getBoolean("isadmin");
}
}catch (Exception e) {
System.out.println(e);
} finally {
if (conn != null) {
try {
conn.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (ps != null) {
try {
ps.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
if (rs != null) {
try {
rs.close();
} catch (SQLException e) {
e.printStackTrace();
}
}
}
return isValid;
}
public static Boolean admin(){
return isadmin;
}
}
loginservelet.java：
package com.example.saeid;
import java.io.IOException;
import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.io.PrintWriter;
import com.example.saeid.LoginCheck;
public class LoginServlet extends HttpServlet{
private static final long serialVersionUID = 1L;
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
PrintWriter out = response.getWriter();
String n=request.getParameter("username");
String p=request.getParameter("userpass");
int p2 = Integer.parseInt(p);
HttpSession session = request.getSession(false);
if(session!=null)
session.setAttribute("name", n);
if(LoginCheck.validate(n, p2)){
if(LoginCheck.admin()){
RequestDispatcher rd=request.getRequestDispatcher("welcome.jsp");
rd.forward(request,response);
}
else{
RequestDispatcher rd=request.getRequestDispatcher("NewFile.jsp");
rd.forward(request,response);
}
}
else{
out.print("<p style=\"color:red\">Sorry username or password error</p>");
RequestDispatcher rd=request.getRequestDispatcher("index.jsp");
rd.include(request,response);
}
out.close();
}
}
register.java：
package com.example.saeid;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import java.sql.*;
public class Register extends HttpServlet {
private static final long serialVersionUID = 1L;
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
String name = request.getParameter("name");
String pass1 = request.getParameter("pass");
int pass = Integer.parseInt(pass1);
String email = request.getParameter("email");
try{
//loading drivers for mysql
Class.forName("com.mysql.jdbc.Driver");
//creating connection with the database
String db_userName = "root";
String db_Password = "uyhgbv098";
String url = "jdbc:mysql://localhost:3306/";
String db_Name = "my_demo_database";
Connection con=DriverManager.getConnection
(url+db_Name,db_userName,db_Password);
PreparedStatement ps=con.prepareStatement
("insert into user_acount values(?,?,?)");
ps.setString(1, name);
ps.setInt(2, pass);
ps.setString(3, email);
int i=ps.executeUpdate();
if(i>0)
{
out.println("You are sucessfully registered");
}
}
catch(Exception se)
{
se.printStackTrace();
}
}
}
的web.xml：
<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://xmlns.jcp.org/xml/ns/javaee" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" id="WebApp_ID" version="3.1">
<display-name>FirstHomework</display-name>
<welcome-file-list>
<welcome-file>index.jsp</welcome-file>
</welcome-file-list>
<servlet>
<servlet-name>login</servlet-name>
<servlet-class>com.example.saeid.LoginServlet</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>login</servlet-name>
<url-pattern>/loginServlet</url-pattern>
</servlet-mapping>
<servlet>
<servlet-name>register</servlet-name>
<servlet-class>com.example.saeid.Register</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>register</servlet-name>
<url-pattern>/Register</url-pattern>
</servlet-mapping>
</web-app>
請縮小完成您的問題 –