function vertify(){
//jquery对象
var jqueryObj = $("#userName");
//获取节点的值
var userName = jqueryObj.val();
//弹出值
alert(userName+"hello");
//使用jquery的XMLHTTPrequest对象get请求的封装。
$.get("AJAXServer?name="+userName,null,myCallBackFun);
}function myCallBackFun(){
alert("dd");//这里调用不到
}
照着视频做,callback函数调用不到,不知是什么原因
//jquery对象
var jqueryObj = $("#userName");
//获取节点的值
var userName = jqueryObj.val();
//弹出值
alert(userName+"hello");
//使用jquery的XMLHTTPrequest对象get请求的封装。
$.get("AJAXServer?name="+userName,null,myCallBackFun);
}function myCallBackFun(){
alert("dd");//这里调用不到
}
照着视频做,callback函数调用不到,不知是什么原因
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.ServletException;
import java.io.IOException;
import java.io.PrintWriter;
import java.net.URLDecoder;
@SuppressWarnings("serial")
public class AJAXServer extends HttpServlet{
protected void doPost(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
doGet(httpServletRequest, httpServletResponse);
} protected void doGet(HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws ServletException, IOException {
try{
// request.setCharacterEncoding("UTF-8");
// response.setContentType("text/html;charset=gb18030"); httpServletResponse.setContentType("text/html;charset=utf-8");
PrintWriter out = httpServletResponse.getWriter(); Integer inte = (Integer) httpServletRequest.getSession().getAttribute("total");
int temp = 0;
if (inte == null) {
temp = 1;
} else {
temp = inte.intValue() + 1;
}
httpServletRequest.getSession().setAttribute("total",temp); //1.取参数
String old = httpServletRequest.getParameter("name");
//String name = new String(old.getBytes("iso8859-1"),"UTF-8");
String name = URLDecoder.decode(old,"UTF-8");
//2.检查参数是否有问题
if(old == null || old.length() == 0){
out.println("用户名不能为空");
} else{
// String name = URLDecoder.decode(old,"UTF-8");
// byte[] by = old.getBytes("ISO8859-1");
// String name = new String(by,"utf-8");
// String name = URLDecoder.decode(old,"utf-8");
//3.校验操作
// String name = old;
if(name.equals("wangxingkui")){
//4。和传统应用不同之处。这一步需要将用户感兴趣的数据返回给页面段,而不是将一个新的页面发送给用户
//写法没有变化,本质发生了改变
out.println("用户名[" + name + "]已经存在,请使用其他用户名, " + temp);
} else{
out.println("用户名[" + name + "]尚未存在,可以使用该用户名注册, " + temp);
}
}
} catch(Exception e){
e.printStackTrace();
}
}
}
$.get("AJAXServer,{name:userName},myCallBackFun,"json");
这样看看 如果没调到看看你后台有没有出错 或用调下脚本看看responseText是什么
1.“$.get("AJAXServer?name="+userName,null,myCallBackFun);”中的对url是否正确
2. 如果能请求到servlet,看看AJAXServer.java中有没有抛出异常
3. 清空一下tomcat和浏览器的缓存,重启tomcat;顺便说一下,LZ贴的代码应该只是事例吧?没有注意到代码的规范,数据流用完之后要关闭
$.get("AJAXServer?name="+userName,null,myCallBackFun);这个url具体是怎么定义的呢?