版权声明:你们随意 我不奉陪了 https://blog.csdn.net/zuoside__lord/article/details/85224870
防止我下次不会写,,所以 先放在这里。
ajax部分
function showHint(str)
{
//out.println("xxxxxxxx!");
var xmlhttp;
if (str.length==0)
{
document.getElementById("txtHint").innerHTML="";
return;
}
if (window.XMLHttpRequest)
{
// IE7+, Firefox, Chrome, Opera, Safari 浏览器执行代码
xmlhttp=new XMLHttpRequest();
}
else
{
// IE6, IE5 浏览器执行代码
xmlhttp=new ActiveXObject("Microsoft.XMLHTTP");
}
xmlhttp.onreadystatechange=function()
{
if (xmlhttp.readyState==4 && xmlhttp.status==200)
{
document.getElementById("txtHint").innerHTML=xmlhttp.responseText;
}
}
xmlhttp.open("post","loginServelt?username="+str,true);
xmlhttp.send();
}
</script>
jsp部分:格式没有调 就是一个表格
<form action="loginServelt" method="post">
<div class="row form-group">
<div class="col-md-12">
<label for="username">Username or Email</label>
<input type="text" class="form-control" id="username" onkeyup="showHint(this.value)"/><!-- 此处需要ajax-->
<p style="color:red"><span id="txtHint"></span></p>
</div>
</div></form>
servelt部分
package servelt;
import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* Servlet implementation class loginServelt
*/
//注册
public class loginServelt extends HttpServlet {
private static final long serialVersionUID = 1L;
/**
* @see HttpServlet#HttpServlet()
*/
public loginServelt() {
super();
// TODO Auto-generated constructor stub
}
/**
* @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
request.setCharacterEncoding("utf-8");
response.setContentType("text/html;charset=UTF-8");
String name=request.getParameter("username");
String password=request.getParameter("password");//
response.getWriter().write("Username is been taken ");
}
/**
* @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
// TODO Auto-generated method stub
doGet(request, response);
}
}