<script type='text/javascript'> //实现功能,对用户名是否被注册进行验证 //验证时间onblur //服务器是tomacat与servlet结合作为服务器端 //浏览器在ff与chrome下测试,版本应就是近期才装的 //服务器端假设各位已会 //ajax函数 var ajax=function(url){ var xhr=null; if(window.XMLHttpRequest){ xhr=new XMLHttpRequest(); }else{ xhr=new ActiveXObject("Microsoft.XMLHTTP"); } xhr.open("get", url, true); xhr.send(); xhr.onreadystatechange=function(){ if(xhr.readyState==4 && xhr.status==200){ //console.info(xhr.responseText); //console.info(xhr.responseXML);//为null alert(xhr.responseText); } }; }; window.οnlοad=function(){ var oInputs=document.getElementsByTagName('input'); var url="AjaxServlet?userName="+oInputs[0].value; oInputs[0].οnblur=function(){ ajax(url); }; }; </script> </head> <body> <form action=""> userName<input type="text" name="userName"/><br/> password<input type='text' name="passWord"/> </form> </body>
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html");
response.setCharacterEncoding("UTF-8");
String s1=request.getParameter("userName");
if(s1.equals("userName")){
PrintWriter out = response.getWriter();
out.print("名字相同111");
out.flush();
out.close();
}else{
PrintWriter out = response.getWriter();
out.print("success");
out.flush();
out.close();
}
}
<servlet> <description>This is the description of my J2EE component</description> <display-name>This is the display name of my J2EE component</display-name> <servlet-name>AjaxServlet</servlet-name> <servlet-class>hyl.AjaxServlet</servlet-class> </servlet> <servlet-mapping> <servlet-name>AjaxServlet</servlet-name> <url-pattern>/AjaxServlet</url-pattern> </servlet-mapping> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list>
//给上结果图