无法从 jsp 调用 servlet 文件 - 发现 404 错误

Question

我的索引页面已更改为 Register_1.jsp 并也在 xml 文件中进行了更新，该页面运行正常，带有连接 servlet 文件的操作字段 Guru_register i在下图中的 Eclipse 中添加了 jsp 代码以及 java 代码和结构请帮助我在此先感谢...!!

Register_1.jsp

<body>
<h1>Guru Register Form</h1>
<form action="Guru_register.java" method="post">
            <table style="with: 50%">
                <tr>
                    <td>First Name</td>
                    <td><input type="text" name="first_name" /></td>
                </tr>
                <tr>
                    <td>Last Name</td>
                    <td><input type="text" name="last_name" /></td>
                </tr>
                <tr>
                    <td>UserName</td>
                    <td><input type="text" name="username" /></td>
                </tr>
                    <tr>
                    <td>Password</td>
                    <td><input type="password" name="password" /></td>
                </tr>
                <tr>
                    <td>Address</td>
                    <td><input type="text" name="address" /></td>
                </tr>
                <tr>
                    <td>Contact No</td>
                    <td><input type="text" name="contact" /></td>
                </tr></table>
            <input type="submit" value="Submit" /></form>
</body>

Register_2.jsp

<%@ page language="java" contentType="text/html; charset=ISO-8859-1"
    pageEncoding="ISO-8859-1"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>Guru Success Page</title>
</head>
<body>
           <a><b>Welcome User!!!!</b></a>
</body>
</html>

我的 servlet class

public class Guru_register extends HttpServlet {
    private static final long serialVersionUID = 1L;


     protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        String first_name = request.getParameter("first_name");
        String last_name = request.getParameter("last_name");
        String username = request.getParameter("username");
        String password = request.getParameter("password");
        String address = request.getParameter("address");
        String contact = request.getParameter("contact");
        System.out.println(first_name+" "+contact);
        if(first_name.isEmpty() || last_name.isEmpty() || username.isEmpty() || 
                password.isEmpty() || address.isEmpty() || contact.isEmpty())
        {
            RequestDispatcher req = request.getRequestDispatcher("Register_1.jsp");
            req.include(request, response);
        }
        else
        {
            RequestDispatcher req = request.getRequestDispatcher("Register_2.jsp");
            req.forward(request, response);
        }
    }

}

我尝试了两种方式提交带有值的表单，但没有任何一种方式出现相同的错误。

Answer 1

你需要在动作中给Servlet Name，不需要指定任何东西；

<body>
<h1>Guru Register Form</h1>
<form action="Guru_register" method="post">

//带注解的Servlet

@WebServlet("/Guru_register")
public class Guru_register extends HttpServlet {
    private static final long serialVersionUID = 1L;

Answer 2

尝试将 servlet 信息添加到 web.xml 首先将你的 servlet 移动到一个包中，我们称之为 'controllers'，因此文件的新位置将是 src > controllers > Guru_register.java

<servlet>
    <servlet-name>Guru_register</servlet-name>
    <servlet-path>controllers.Guru_register</servlet-path>
</servlet>
<servlet-mapping>
    <servlet-name>Guru_register</servlet-name>
    <url-pattern>/guru-register</url-pattern>
</servlet-mapping>

接下来，修改jsp表格如下：

<form action="guru-register" method="post">

无法从 jsp 调用 servlet 文件 - 发现 404 错误

Unable to call servlet file from jsp - 404 error found

jsp

servlets

http-status-code-404