Java+Web聊天室系统源码

【核心代码】

package com.wgh.servlet;

import com.wgh.model.UserInfo;
import java.io.*;
import java.util.Date;
import java.util.Random;
import java.util.Vector;

import java.util.logging.Level;
import java.util.logging.Logger;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.*;



public class Messages extends HttpServlet {
    /**
     * Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    protected void processRequest(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        response.setContentType("text/html;charset=UTF-8");
		String action = request.getParameter("action");
        if ("loginRoom".equals(action)) {	//登录时，写入系统公告
            this.loginRoom(request, response);
        } else if ("sendMessage".equals(action)) {	//发送聊天信息
            this.sendMessages(request, response);
        } else if ("getMessages".equals(action)) {		//从XML文件中读取聊天信息
            this.getMessages(request, response);
        }
    }
    	// 将页面重定向到显示聊天信息的页面
	public void getMessages(HttpServletRequest request,HttpServletResponse response) {
        response.setContentType("text/html;charset=UTF-8");
        try {

            request.getRequestDispatcher("content.jsp").forward(request, response);

        } catch (Exception ex) {
            Logger.getLogger(Messages.class.getName()).log(Level.SEVERE, null, ex);
        }

	}

	// 登录时，写入系统公告

	public void loginRoom(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
		response.setContentType("text/html;charset=UTF-8");
		HttpSession session = request.getSession();
		String username=request.getParameter("username");	//获得登录用户名
		UserInfo user=UserInfo.getInstance();		//获得UserInfo类的对象
		session.setMaxInactiveInterval(600);		//设置Session的过期时间为10分钟
		Vector vector=user.getList();
		boolean flag=true;		//标记是否登录的变量
		//判断用户是否登录
		System.out.println("vector的size：" vector.size());
		if(vector!=null&&vector.size()>0){
			for(int i=0;i<vector.size();i  ){
				System.out.println("vector" i ":" vector.elementAt(i) " user:" username);
				if(username.equals(vector.elementAt(i))){
					PrintWriter out;
					try {
						out = response.getWriter();
						out.println("<script language='javascript'>alert('该用户已经登录');window.location.href='index.jsp';</script>");
					} catch (IOException e) {
						e.printStackTrace();
					}
					flag=false;
					break;
				}
			}
		}
		//保存用户信息
		if(flag){
			UserListener ul=new UserListener();					//创建UserListener的对象
			ul.setUser(username);								//添加用户
			user.addUser(ul.getUser());							//添加用户到UserInfo类的对象中
			session.setAttribute("user",ul);						//将UserListener对象绑定到Session中
			session.setAttribute("username",username);	//保存当前登录的用户名
			session.setAttribute("loginTime",new Date().toLocaleString());		//保存登录时间
        ServletContext application=getServletContext();

        String sourceMessage="";

        if(null!=application.getAttribute("message")){
            sourceMessage=application.getAttribute("message").toString();
        }
        sourceMessage ="系统公告：<font color='gray'>"   username   "走进了聊天室！</font><br>";
        application.setAttribute("message",sourceMessage);
        try {
            request.getRequestDispatcher("login_ok.jsp").forward(request, response);
        } catch (Exception ex) {
            Logger.getLogger(Messages.class.getName()).log(Level.SEVERE, null, ex);
        }
		}
	}

	// 发送聊天信息
    public void sendMessages(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
            response.setContentType("text/html;charset=UTF-8");
            request.setCharacterEncoding("UTF-8");
            Random random = new Random();
            String from = request.getParameter("from"); //发言人
            String face = request.getParameter("face"); //表情
            String to = request.getParameter("to"); //接收者
            String color = request.getParameter("color"); //字体颜色
            String content = request.getParameter("content"); //发言内容
            String sendTime = new Date().toLocaleString(); //发言时间
            ServletContext application = getServletContext();
            String sourceMessage = application.getAttribute("message").toString();
            try {
                //发言时间
                sourceMessage  = "<font color='blue'><strong>"   from   "</strong></font><font color='#CC0000'>"   face   "</font>对<font color='green'>["   to   "]</font>说："   "<font color='"   color   "'>"   content   "</font>（"   sendTime   "）<br>";
                application.setAttribute("message", sourceMessage);
                request.getRequestDispatcher("Messages?action=getMessages&nocache="   random.nextInt(10000)).forward(request, response);
            } catch (Exception ex) {
                Logger.getLogger(Messages.class.getName()).log(Level.SEVERE, null, ex);
            }

	}


// <editor-fold defaultstate="collapsed" desc="HttpServlet 方法。单击左侧的   号以编辑代码。">
    /**
     * Handles the HTTP <code>GET</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Handles the HTTP <code>POST</code> method.
     * @param request servlet request
     * @param response servlet response
     * @throws ServletException if a servlet-specific error occurs
     * @throws IOException if an I/O error occurs
     */
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        processRequest(request, response);
    }

    /**
     * Returns a short description of the servlet.
     * @return a String containing servlet description
     */
    @Override
    public String getServletInfo() {
        return "Short description";
    }// </editor-fold>


}