ServletContext:Servlet上下文--这是今天测试做的简易聊天室的核心代码
<%@ 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>Insert title here</title>
</head>
<body>
<form action="sss" method="post">
<input type="text" name = "sayMsg" style=" 640px;height:20px;">
<input type="submit" value="发送">
</form>
</body>
</html>
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.Date;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
@WebServlet("/sss")
public class FayanServlet extends HttpServlet {
private static final long serialVersionUID = 1L;
public FayanServlet() {
super();
// TODO Auto-generated constructor stub
}
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
request.setCharacterEncoding("utf-8");
//获取发言人的名称
HttpSession session = request.getSession();
String name = (String)session.getAttribute("name");
//获取发言人说的话
String msg = request.getParameter("sayMsg");
//获取其他人说的话
ServletContext sc = getServletContext();
String talk = "";
if(sc.getAttribute("talk")!=null){
talk = (String)sc.getAttribute("talk");
}
//获取发言的时间
SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
Date date = new Date();
String time = format.format(date);
//组合发言的内容
StringBuffer str = new StringBuffer();
str.append(talk);
str.append("<br>");
str.append(name);
str.append("说：["+time+"]<br>");
str.append(msg);
//将发言内容保存到ServletContext中
sc.setAttribute("talk",str.toString());
response.sendRedirect("talk.jsp");
}
}
最后的效果：