要自己做一个聊天室
在这里写下思路
聊天室，首先就是要有信息的收发
也就是收集和显示
信息显示 chatinfo.jsp <body> <table align="center" cellspacing="10"> <tr> <td colspan="3"><textarea rows="20" cols="80">${applicationScope.talks}</textarea> </td> </tr> </table> </body>
信息收集
index.jsp <body> <table align="center"> <tr> <td colspan="2"> <iframe src="chatinfo.jsp" width="800px" height="460px"></iframe> </td> </tr> <tr> <td align="center"> <form action="chat.do" method="post"> <input type="text" name="chat" size="60"> <input type="submit" value="发言"> </form> </td> </tr> </table> </body>
前端搞定了，就要想想怎么写后面
由于不用数据库
发送的信息一定要保存在服务器端
根据其存在时间，我觉得用servletcontext来最好
写个监听器监听servletcontext
public class ContextListener implements ServletContextListener {
public static final String Talks = "talks";
//static final 静态最终啥的玩意 其实就是放在application里的数据
//Talks是服务器内部调用的 ContextListener.Talks
//talks是web前端调用的 applicationScope.talks
private StringBuilder talks = new StringBuilder();
@Override
public void contextDestroyed(ServletContextEvent sce) {
// TODO Auto-generated method stub
sce.getServletContext().removeAttribute(Talks);
}
@Override
public void contextInitialized(ServletContextEvent sce) {
// TODO Auto-generated method stub
sce.getServletContext().setAttribute(Talks, talks);
}
}
最后上个servlet就好了
其中的dopost方法
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException { String talk=req.getParameter("talks"); ServletContext sc = this.getServletContext(); StringBuilder sb = (StringBuilder) sc .getAttribute(ContextListener.Talks); sb.append(String.format("说：%s%n", talk)); resp.sendRedirect(req.getContextPath() + "/index.jsp"); }
最后web.xml我就不写了