这篇文章主要为大家详细介绍了java-web实现简单聊天室，含拍一拍功能，文中示例代码介绍的非常详细，具有一定的参考价值，感兴趣的小伙伴们可以参考一下
目标
servlet、jsp实现简单聊天室，用户通过浏览器登录后进入聊天室，可发送消息进行群聊，点击聊天信息框中的用户名可实现拍一拍功能。
基础知识
- 数据的存取 setAttribute / getAttribute
- request请求对象 ：有效时间短
ServletContext上下文对象：一直存在于服务器，存储公有、 共享数据
Session会话对象：独立
- 网站默认页面一般是index.jsp
实现思路
1.登录页面 login.jsp 输入昵称
2.编写一个LoginSevlet，处理登录提交的昵称，保存登录昵称到session（会话变量）
若昵称合法 if(nickname.length()!=0)，跳转到聊天室，不合法回到登录页面
3.编写聊天室页面chatroom.jsp ，是一个框架，把多个页面集成到一个页面中
4.聊天内容显示message.jsp，不断自动刷新标签内设置响应头,用${上下文变量}显示聊天内容
5.input.jsp（不刷新）输入聊天内容文本框text，点击发送聊天内容按钮时，将把文本框的聊天信息提交给ChatServlet处理。下方有超链接可退出聊天室。
退出聊天室
6.ChatServlet：<span style="color: #800000">把聊天信息加入到ServletContext变量</span>（字符串）中，（每次都将xx:xxxx加入上下文字符串）检测聊天信息合法性，
判断是否存在该变量，存在则直接读取现有聊天内容，把数据加入进去后，重新写回上下文变量
7.实现拍一拍功能（目的：学习如何进行链接操作）
每个人名做成一个链接，访问某一个servlet，该servlet可以在聊天信息（上下文变量）里添加一行，xx拍了yyy一下，跳转回message.jsp
问题：链接里应该包含yyy参数，servlet？nick=yyy
say = ""+nickname+""+":"+text;
8.多人聊天实现：多种类型浏览器
关键代码
login.jsp
昵称：[object Object] [object Object][object Object]
input.jsp
退出聊天室
message.jsp
一起来聊天吧${says}LoginServlet.java
package chatting; import javax.servlet.RequestDispatcher; 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; import java.io.IOException; import java.io.PrintWriter; @WebServlet(name = "LoginServlet2",urlPatterns = {"/login.do"}) public class LoginServlet2 extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //避免乱码 response.setContentType("text/html;charset=utf-8"); request.setCharacterEncoding("utf-8"); //nickname保存用户昵称 String nickname = request.getParameter("nickname"); //nickname存储到session变量中 HttpSession session = request.getSession(); session.setAttribute("nickname",nickname); //对nickname进行合法性判断 if(nickname.length()!=0){ //昵称合法，则进入聊天室页面 request.getRequestDispatcher("/chatroom.jsp").forward(request,response); } else{ //昵称不合法，返回登陆页面 request.getRequestDispatcher("/login.jsp").forward(request,response); } } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } }ChatServlet.java
package chatting; import javax.servlet.RequestDispatcher; 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; import java.io.IOException; import java.util.Vector; @WebServlet(name = "ChatServlet",urlPatterns = "/input.do") public class ChatServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { //防止乱码 request.setCharacterEncoding("utf-8"); response.setContentType("text/html;charset=utf-8"); HttpSession session = request.getSession(); String text = request.getParameter("text"); //text存储聊天信息，并进行合法性判断 if (text.length()!=0) { String say =new String(); //获取session中的昵称 String nickname = (String)session.getAttribute("nickname"); //将昵称作为链接，并传参 say = ""+":"+text; String says = new String(); //将昵称和聊天信息一起放在上下文变量 ServletContext context = getServletContext(); if(context.getAttribute("says")!=null){ says = context.getAttribute("says") + say + "
"; } else{ says = say + "
"; } context.setAttribute("says", says); request.setAttribute("says", says); } //转发 RequestDispatcher dispatcher = request.getRequestDispatcher("/input.jsp"); dispatcher.forward(request, response); } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } }NickServlet.java
package chatting; import javax.servlet.RequestDispatcher; 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; import java.io.IOException; import java.io.PrintWriter; @WebServlet(name = "NickServlet",urlPatterns = "/NickServlet") public class NickServlet extends HttpServlet { protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { } protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { response.setContentType("text/html;charset=UTF-8"); request.setCharacterEncoding("utf-8"); //将拍一拍放到上下文变量says中 一起输出 HttpSession session = request.getSession(); //nickname存储当前用户昵称 String nickname = (String)session.getAttribute("nickname"); //name存储连接中传递的参数，即被拍的用户昵称 String name = java.net.URLDecoder.decode(request.getParameter("nickname"),"UTF-8"); String pick = nickname+"拍了拍"+name+"
"; ServletContext context = request.getServletContext(); String says = context.getAttribute("says")+pick; context.setAttribute("says",says); RequestDispatcher dispatcher = request.getRequestDispatcher("/chatroom.jsp"); dispatcher.forward(request, response); } }以上就是java web实现简单聊天室的详细内容，更多请关注0133技术站其它相关文章！
