mytalkroom.java

该系统实现的是一个在线聊天的一个小应用程序

package com.berheley.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import com.berheley.listener.Counter;
import com.berheley.utils.Converter;
import com.fun.Convert;

/**
 * 
 * @author 赵肖强 
 * 对request请求的转发类
 * 
 */
public class MyTalkRoom extends HttpServlet {
	/**
	 * 功能：添加用户列表，添加发言内容并存储。
	 */
	protected void doGet(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		ServletContext context = this.getServletContext();
		HttpSession session = request.getSession();
		PrintWriter out=response.getWriter();
		// 设置页面刷新
		// String url="http://localhost:8080/mychat/MyTalkRoom";
		// response.setHeader("Refresh","5");
		// 用户集合
		Set userset = null;
		List contentList = null;
		//如果是第一个登录的用户
		if (context.getAttribute("set") == null) {
			userset = new HashSet();
		} else {
			userset = (Set) context.getAttribute("set");
		}
		//如果是第一个用户登录，还没有进行发言，则初始化
		if (context.getAttribute("list") == null) {
			contentList = new ArrayList();
		} else {
			contentList = (List) context.getAttribute("list");
		}
		// 用来判断是登录还是发言
		String username = null;
		if (session.getAttribute("index") == null) {
			session.setAttribute("index", new Integer(1));
			// 若用户名不合法，则返回登录页面
			if (request.getParameter("username") == null
					|| request.getParameter("username").toString().equals("")) {
				response.sendRedirect("index.jsp");
			} else {
				username = request.getParameter("username").toString();
				userset.add(username);
				session.setAttribute("username", username);
				context.setAttribute("set", userset);
				response.sendRedirect("talk.jsp");
			}
		} else {
			if (request.getParameter("content") != null
					&& (!request.getParameter("content").toString().equals(""))) {
				String name = session.getAttribute("username").toString();
				String content = request.getAttribute("content").toString();
				contentList.add(name + " 说:"+ content);
				context.setAttribute("set", userset);
				// 把发言的内容保存在contentList中
				context.setAttribute("list", contentList);
				out.print(content);
				out.flush();
				//return null;
				//response.sendRedirect("talk.jsp");
			} else {
				response.sendRedirect("talk.jsp");
			}
		}
	}

	/**
	 * 
	 */
	protected void doPost(HttpServletRequest request,
			HttpServletResponse response) throws ServletException, IOException {
		doGet(request, response);
	}
}