JSP页面在Servlet程序中不起作用

Question

Actually i'm trying to display the details obtained from JSP form with servlet. 实际上，我正在尝试显示从JSP表单使用servlet获得的详细信息。 But I'm not able to display the JSP page. 但是我无法显示JSP页面。 But I can see the program entering into the POST method in Servlet. 但是我可以看到程序进入Servlet中的POST方法。

Here is my code, 这是我的代码，

Startup.jsp Startup.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>Insert title here</title>
</head>
<body>
 <form action="controlServlets" method="post">
        <input type="text" name="name"/><br>        
        <input type="text" name="group"/>
        <input type="text" name="pass"/>
        <input type="submit" value="submit">            
    </form>

</body>
</html>

web.xml web.xml

<web-app>

  <servlet>
    <servlet-name>controlServlets</servlet-name>
    <servlet-class>com.selenium8x8.servlet.ControlServlets</servlet-class>
  </servlet>
  <servlet-mapping>
    <servlet-name>controlServlets</servlet-name>
    <url-pattern>/*</url-pattern>
  </servlet-mapping>

</web-app>

ControlServlets.java ControlServlets.java

import java.io.IOException;

import javax.servlet.RequestDispatcher;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

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


    public ControlServlets() {
        super();
        // TODO Auto-generated constructor stub
    }


//    @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 name = request.getParameter("name");
            String group = request.getParameter("group");
            String pass = request.getParameter("pass");
            System.out.println("Name :"+ name);
            System.out.println("group :"+ group);
            System.out.println("pass :"+ pass);
            System.out.println("Post method");
    }

}

In console, 在控制台中

I can see the following, 我可以看到以下内容

Name :null
group :null
pass :null
Post method

Please Help... 请帮忙...

Answer 1

Part I)If you want to use web.xml for your application then you need to make following changes : 第一部分）如果要为应用程序使用web.xml ，则需要进行以下更改：

1)In Startup.jsp change the action attribute of <form> tag to 1）在Startup.jsp将<form>标记的action属性更改为

<form action="ControlServlets" method="post"> 
              ↑

2)In web.xml change the <servlet-mapping> to 2）在web.xml将<servlet-mapping>更改为

<servlet-mapping>
 <servlet-name>controlServlets</servlet-name>
 <url-pattern>/ControlServlets</url-pattern> 
</servlet-mapping>

3)In ControlServlets.java several changes as, in web.xml you mentioned 3）在ControlServlets.java中，您提到了web.xml一些更改

<servlet-class>com.selenium8x8.servlet.ControlServlets</servlet-class>
                ↑

This is the package name, so you must have first statement in ControlServlets.java 这是程序包名称，因此您必须在ControlServlets.java具有第一条语句

package com.selenium8x8.servlet;  //in your code it is missing

Then, comment following two lines 然后，评论以下两行

//import javax.servlet.annotation.WebServlet;

and 和

//@WebServlet("/ControlServlets")

Now, run application, it will give you desired output. 现在，运行应用程序，它将为您提供所需的输出。

Part II) If you want to use @WebServlet annotation, as you did 第二部分）如果您想像使用@WebServlet注释那样

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

@WebServlet("/ControlServlets")
public class ControlServlets extends HttpServlet {   
  ...
  .....
  .......
}

Then, no need for web.xml . 然后，不需要web.xml 。 The above does basically the same as following: 上面的内容基本上与以下内容相同：

<servlet>
 <servlet-name>controlServlets</servlet-name>
 <servlet-class>com.selenium8x8.servlet.ControlServlets</servlet-class>
</servlet>
<servlet-mapping>
 <servlet-name>controlServlets</servlet-name>
 <url-pattern>/ControlServlets</url-pattern>
</servlet-mapping>

For using @WebServlet annotation you need Java EE 6 / Servlet 3.0 为了使用@WebServlet批注，您需要Java EE 6 / Servlet 3.0

JSP页面在Servlet程序中不起作用

问题描述

1 个解决方案

解决方案1
1 已采纳 2013-10-18 06:50:35

JSP页面在Servlet程序中不起作用

问题描述

1 个解决方案

解决方案1 1 已采纳 2013-10-18 06:50:35

解决方案1
1 已采纳 2013-10-18 06:50:35