java web实现简单聊天室

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html中文网其它相关文章!

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