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java - JSP页面在Servlet程序中不起作用

转载 作者:行者123 更新时间:2023-12-01 13:59:45 24 4
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实际上,我正在尝试使用 servlet 显示从 JSP 表单获得的详细信息。但我无法显示 JSP 页面。但我可以看到程序进入Servlet中的POST方法。

这是我的代码,

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-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

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");
}

}

在控制台中,

我可以看到以下内容,

Name :null
group :null
pass :null
Post method

请帮忙...

最佳答案

第一部分)如果您想使用web.xml对于您的应用程序,您需要进行以下更改:

1) 在 Startup.jsp更改 action <form> 的属性标记为

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

2) 在 web.xml更改 <servlet-mapping>

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

3) 在 ControlServlets.java一些变化,如web.xml你提到了

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

这是包名称,因此您必须在ControlServlets.java中有第一个语句

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

然后,注释下面两行

//import javax.servlet.annotation.WebServlet;

//@WebServlet("/ControlServlets")

现在,运行应用程序,它将为您提供所需的输出。

<小时/>

第二部分)如果您想使用@WebServlet注释,就像你所做的那样

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 {
...
.....
.......
}

那么,不需要 web.xml 。上面的代码与下面的代码基本相同:

<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>

使用@WebServlet您需要的注释Java EE 6 / Servlet 3.0

关于java - JSP页面在Servlet程序中不起作用,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/19408937/

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