实现通过表单向servlet中传送数据，配置webxml后一直显示HHTP404,但我把添加的配置内容删掉后反而可以运行了
web.xml配置：
<servlet>
<servlet-name>ComputeBill</servlet-name>
<servlet-class>myservlet.ComputeBill</servlet-class>
</servlet>
<servlet-mapping>
<servlet-name>ComputeBill</servlet-name>
<url-pattern>/ComputeBill</url-pattern>
</servlet-mapping>
jsp代码：
<%@ page language="java" contentType="text/html; charset=UTF-8"
pageEncoding="UTF-8"%>
<!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=UTF-8">
<title>利用表单给servlet传送数据</title>
</head>
<body>
<form action="ComputeBill" method="post">
输入账单：<br>
<textarea name='billMess' rows="5" cols="30">
</textarea>
<br>
<input type=submit value="提交">
</form>
</body>
</html>
servlet代码（省略导包）：
public class ComputeBill extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public ComputeBill() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see Servlet#init(ServletConfig)
*/
public void init(ServletConfig config) throws ServletException {
// TODO Auto-generated method stub
super.init(config);
}
/**
* @see HttpServlet#service(HttpServletRequest request, HttpServletResponse response)
*/
protected void service(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
//1、设置编码格式
request.setCharacterEncoding("UTF-8");
response.setContentType("text/html;charset=UTF-8");
//2、利用printwriter类输出流声明out对象，利用response对象调用getwriter方法获取一个输出流，利用out对象调用print方法
PrintWriter out=response.getWriter();
out.print("<html><body bgcolor=yellow>");
//3、通过request对象获取表单中文本区的内容送给str
String str=request.getParameter("billMess");
if(str==null||str.length()==0)
return;
String [] price=str.split("[^0123456789.]+");
double sum=0;
try
{
for(int i=0;i<price.length;i++)
{
if(price[i].length()>=1)
sum+=Double.parseDouble(price[i]);
}
}
catch(NumberFormatException e){out.print(e);}
out.print(str+"<br>的消费额:"+sum+"元");
out.print("</body></html>");
}
