String userName=request.getParameter("userName");什么意思

request.getParameter("username") == null "" :request.getPara Username 什么意思? 关于Trim（）string UserName = txtUserName.Text;和string UserName jsp中的内容 String str=request.getParameter("guessnumber"); // 这 JSP中,String s2=new String(request.getParameter("s1").trim(). username should contain alphabets,numbers什么意思 this username is available什么意思? Username unavailable 意思 username@examplecom是甚么意思 The username or password you entered is incorrect什么意思 login failed,incorrect username or possword什么意思 Your username or password is incorrect什么意思?