处理通过 ajax 调用从 servlet 返回的“成功”字符串

我有一个 servlet，它接受我的 ajax 请求，它将用户名和密码作为参数从我的 ExtJs 项目中的 LoginView 传递。这是相同的代码：

public class UserLoginController  extends MultiActionController {
OrgTreeService orgTreeService;
ModelAndView mv;
public String getLoginStatus(HttpServletRequest paramHttpServletRequest, HttpServletResponse paramHttpServletResponse)
        throws Exception{
    String str1 = paramHttpServletRequest.getParameter("user");
    String str2 = paramHttpServletRequest.getParameter("password");
    String s="";
      System.out.println("---node"+str1);
      System.out.println("---node"+str2);
      if(str1.equals("admin") && str2.equals("admin")){
          s="success";
      }else{
          s="failure";
      }

      return s;
}

这就是我从我的观点发出 ajax 请求的方式：

doLoginClicked : function() {
    console.log("button pressed this time");
    var name = this.view.getUsername();
    var pass = this.view.getPassword();
    console.log(name);
    console.log(pass);
    Ext.Ajax.request({
        url: 'login/getLoginStatus.action',
        method:'post',
        params: {
            user: name,
            password: pass
            }
    ,
            success: function(response) {

                console.log(response);

                if (response=="success") { 
                  //  login.close(); 

                } else {
                    console.log("inside failure");

                    Ext.Msg.show({
                        title:'Fail!',
                        msg: response, 
                        icon: Ext.Msg.ERROR,
                        buttons: Ext.Msg.OK
                    });
                }
            },
            failure: function(response) {
                console.log("inside failure");
                  Ext.Msg.show({
                        title:'Error!',
                        msg: response,
                        icon: Ext.Msg.ERROR,
                        buttons: Ext.Msg.OK
                    });
                }
        });
    }

它确实在控制台中显示了来自servlet的用户名和密码，但是我无法接受来自servlet的"成功"响应并采取相应的行动。以下是浏览器控制台中显示的响应：

Object {request: Object, requestId: 1, status: 200, statusText: "OK", responseText: ""…}getAllResponseHeaders: () {arguments: nullcaller: nulllength: 0name: ""prototype: response.getAllResponseHeadersconstructor: () {arguments: nullcaller: nulllength: 0name: ""prototype: response.getAllResponseHeaders__proto__: Empty() {}<function scope>__proto__: Object__proto__: Empty() {}<function scope>getResponseHeader: (header) {request: Objectasync: truebinary: falseheaders: Objectid: 1options: Object__proto__: ObjectrequestId: 1responseText: ""responseXML: nullstatus: 200statusText: "OK"__proto__: Object

有没有办法让我在从 servlet 返回"成功"时显示主页？