Java Servlet HttpServletRequest参数显示为null
我正在尝试从get请求获取表单参数。下面是html代码Java Servlet HttpServletRequest参数显示为null,java,servlets,Java,Servlets,我正在尝试从get请求获取表单参数。下面是html代码 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-e
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>DesignMatch. Matching the best clients and best designers.</title>
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript" src="jquery.backstretch.js"></script>
<script type="text/javascript" src="design_match.js"></script>
<link rel="stylesheet" type="text/css" media="all" href="design_match.css" />
</head>
<body>
<div id="matte_bg"></div>
<div id="entire_wrapper">
<div class="divModule" id="section_head_1">
<p class="primaryPageText">
Clients
</p>
<div class="url-bar">
<form name="clientUrls" action="SaveDatabase2" target="_blank" method="get">
<input type="text" class="url-box" id="url-box1" name="name1" size="20" value="Paste a link to a website that has the design qualities you want.">
<a id="add-url" href="#">Add</a>
<a id="del-url" href="#">Remove</a>
</form>
</div>
</div>
<div class="divModule" id="section_head_2">
<p class="primaryPageText">
Designers
</p>
<div class="portfolio-bar">
<form name="designerUrls" action="SaveDatabase2" target="_blank" method="get">
<input type="text" class="portfolio-box" id="portfolio-box1" name="name1" size="20" value="Paste a link to a website you designed.">
<a id="add-portfolio" href="#">Add</a>
<a id="del-portfolio" href="#">Remove</a>
</form>
</div>
</div>
<div class="divModule">
<div class="filterSentence">
<ul class="primaryPageText">
<li>
To me,
</li>
<li class="budgetTypeFilter">
<a href="#" id="budgetToggle">[what price]</a>
<div id='budgetFilter' style="display:none" class="budgetTypeMenu">
<a href="/500-under">$500 and under</a>
<a href="/500-to-1000">$500-$1,000</a>
<a href="/1000-to-2500">$1,000-$2,500</a>
<a href="/2500-to-5000">$2,500-$5,000</a>
<a href="/5000-to-7500">$5,000-$7,500</a>
<a href="/7500-to-10000">$7,500-$10,000</a>
<a href="/10000-above">Over $10,000</a>
</div>
</li>
<li>
seems fair to pay for
</li>
<li class="budgetTypeFilter">
<a href="#" id="typeToggle">[what type of]</a>
<div id='typeFilter' style="display:none" class="budgetTypeMenu">
<a href="/basic">a basic (e.g., front-end only)</a>
<a href="/dynamic">a dynamic (e.g., a little back-end)</a>
<a href="/sophisticated">a sophisticated (e.g., lots of back-end)</a>
</div>
</li>
<li>
website.
</li>
</ul>
</div>
</div>
<div class="divModule contact-bar" id="contact">
<form name="nameForm" action="SaveDatabase2" target="_blank" method="get">
<input type="text" id="name_form" name="name_form" size="20" value="Tell us your name.">
</form>
<form name="contactForm" action="SaveDatabase2" target="_blank" method="get">
<input type="text" id="contact_form" name="contact_form" size="20" value="Enter your e-mail (no spam, ever).">
</form>
</div>
<div id="submit">
<form accept-charset="UTF-8" action="SaveDatabase2" method="get">
<input class="btn primary large" id="submit-button" name="submit" type="submit" value="✔" />
</form>
</div>
</div>
</body>
</html>
设计匹配。匹配最好的客户和最好的设计师。
客户
设计师
-
对我来说，
-
-
这似乎是公平的
-
-
网站。
package web;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.mysql.jdbc.StringUtils;
import java.sql.*;
import java.io.*;
import java.util.*;
/**
* Servlet implementation class SaveDatabase2
*/
public class SaveDatabase2 extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public SaveDatabase2() {
super();
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doPost(request, response);
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
response.setContentType("text/html");
PrintWriter out = response.getWriter();
out.println("<h1> Thank You </h1>");
//Get Info for Database
int designer=0;
String clientType="";
String name= "";
String email="";
//Get parameters to put into database
Enumeration parameterNames = request.getParameterNames();
if ((request.getParameter("designerUrls")!=null) && !request.getParameter("designerUrls").matches(".*\\w.*") ){
designer=1;
}
if (designer==1){
clientType="designer";
}else clientType="client";
name= request.getParameter("name_form");
email=request.getParameter("contact_form");
}
packageweb；
导入java.io.IOException；
导入javax.servlet.ServletException；
导入javax.servlet.http.HttpServlet；
导入javax.servlet.http.HttpServletRequest；
导入javax.servlet.http.HttpServletResponse；
导入com.mysql.jdbc.StringUtils；
导入java.sql.*；
导入java.io.*；
导入java.util.*；
/**
*Servlet实现类SaveDatabase2
*/
公共类SaveDatabase2扩展了HttpServlet{
私有静态最终长serialVersionUID=1L；
/**
*@参见HttpServlet#HttpServlet（）
*/
公共存储数据库2（）{
超级（）；
}
/**
*@参见HttpServlet#doGet（HttpServletRequest请求，HttpServletResponse响应）
*/
受保护的void doGet（HttpServletRequest请求，HttpServletResponse响应）抛出ServletException，IOException{
//TODO自动生成的方法存根
doPost（请求、响应）；
}
/**
*@请参阅HttpServlet#doPost（HttpServletRequest请求，HttpServletResponse响应）
*/
受保护的void doPost（HttpServletRequest请求、HttpServletResponse响应）引发ServletException、IOException{
//TODO自动生成的方法存根
response.setContentType（“text/html”）；
PrintWriter out=response.getWriter（）；
out.println（“谢谢”）；
//获取数据库的信息
int designer=0；
字符串clientType=“”；
字符串名称=”；
字符串email=“”；
//获取要放入数据库的参数
枚举parameterNames=request.getParameterNames（）；
如果（（request.getParameter（“designerUrls”）！=null）和（&！request.getParameter（“designerUrls”）.matches（（.*\\w.*））{
设计者=1；
}
如果（设计器==1）{
clientType=“设计器”；
}else clientType=“客户端”；
name=request.getParameter（“name_form”）；
email=request.getParameter（“联系人表单”）；
}
doPostdoGet方法设置为post
，将自动触发doPost
此外，您的表格应如下所示：
<form name="myForm" accept-charset="UTF-8" action="SaveDatabase2" target="_blank" method="post">
<input type="text" id="name_form" name="name_form" size="20" value="Tell us your name.">
<input type="text" id="contact_form" name="contact_form" size="20" value="Enter your e-mail (no spam, ever).">
<input class="btn primary large" id="submit-button" name="submit" type="submit" value="✔" />
</form>
在您的问题中，submit按钮是以自己的形式出现的，它不包含两个输入文本字段：name\u form
和contact\u form
。这就是为什么您会得到null
值。我认为您误解了
元素。要将数据从页面发送到servlet，可以使用method=“get”
或method=“post”
-两者仍然以一种方式发送数据（客户端到服务器）。有关差异，请参阅
可以包含许多
，但代码中缺少的关键部分是提交的
（带有
的部分）不包含所需的任何
元素。它们位于未提交的其他
中。仅提交包含提交按钮的
您应该在所有字段和提交按钮周围使用一个
。为什么有这么多标记？您应该只在一个表单标记中包含所有输入字段。非常感谢。其他人做了前端，所以我尝试将其连接到后端，所以我只是假设html没有问题。我打算将其更改为一张表格，看看它是否有效