<javascript>中代码如下:
<script type="text/javascript"> function mycheck() {
//获取用户名文本框里的值 var uname = document.getElementById("uname").value; try { xmlhttp = new ActiveObject("Microsoft.XMLHTTP"); } catch (e) { xmlhttp = new XMLHttpRequest(); } //设置连接,把用户文本框里的值传到servlet中去 xmlhttp.open("post", "../LoginPathServlet?uname=" + uname); //设置请求头信息 xmlhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded"); //设置回调函数 xmlhttp.onreadystatechange = function() { if (xmlhttp.readyState == 4) { if (xmlhttp.status == 200) {
//获取传回来的值 var s = xmlhttp.responseText;
//把图片设置图片路径为用户的图片路径 document.getElementById("tx").src = s; } } } xmlhttp.send(null); } </script>
<body>中代码如下:
<div class="login_title"> <img id="tx" src="默认图片路径 width="50px" height="50px"> </div> <div class="item item-fore1"> <input name="uname" onkeyup="mycheck();" type="text" class="text" id="uname" placeholder="请输入用户"> </div>
Servlet中代码如下:
package servlet; import java.io.IOException; import java.io.PrintWriter; import javax.servlet.servletexception; import javax.servlet.http.HttpServlet; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletResponse; import javax.servlet.http.HttpSession; import entity.Uuser1; import biz.imp_biz.Imp_Uuserbiz; public class LoginPathServlet extends HttpServlet { public void doGet(HttpServletRequest request, HttpServletResponse response) throws servletexception, IOException { doPost(request, response); } public void doPost(HttpServletRequest request, HttpServletResponse response) throws servletexception, IOException { response.setContentType("text/html;charset=utf-8"); // 设置编码 response.setCharacterEncoding("utf-8"); request.setCharacterEncoding("utf-8"); PrintWriter out = response.getWriter(); HttpSession session = request.getSession(); //接收数据 String uname = request.getParameter("uname"); //连接数据库判断用户名是否存在 Imp_Uuserbiz iu = new Imp_Uuserbiz(); Uuser1 u = iu.selectbyname(uname); //设置一个默认图片路径 String str="../upload/hehe.jpg"; //如果用户存在,把用户图片路径传回去 if(u!=null){ if(u.getPhoto()!=null){ str="../"+u.getPhoto(); } } out.print(str); } }
实现后功能: