跨域 Access-Control-Allow-Origin

今天遇到一个问题，所有的代码都一样，只是不同的项目，折腾了快一天了也没发现什么问题，原因却是跨域了。

解决方案：

httpServletResponse.setHeader("Access-Control-Allow-Origin", "*");//跨域

页面js请求信息：

jQuery(function($) {

   $("#login").click(function(){
    $.ajax({
     url:'http://10.16.122.26:8002/iaf-platform-web/doLogin',
     type:'POST',
     data:{
      'loginName':$("[name=username]").val(),
      'userPassword':$("[name=password]").val()
     },
     crossDomain:true,
     dataType :'json',
        success : function(data) {
         if(data.result=='success'){
          window.location.href="../homepage/listMain.html";
         }else{
          $("#loginMsg").html('<i class="ace-icon icon-exclamation-sign"></i> '+data.msg).show();
         }
        },
        error : function(XMLHttpRequest, textStatus, errorThrown) {
      alert("ajax失败！");
            }

    });
   });
  });

Controller方法：

@RequestMapping(value="/doLogin", method=RequestMethod.POST)
 public void login(HttpServletRequest request, HttpServletResponse arg1, Model model){
  try {
   clearSessionAttributes(request.getSession());
   String loginName=request.getParameter("loginName");
   String userPassword=request.getParameter("userPassword");
   LoginResult loginResult = loginService.doLogin(loginName,userPassword);
   SysUser user = loginResult.getSysUser();
   if(user!=null){
    UserContextImpl userContext = new UserContextImpl();
    userContext.setSysUser(user);
    if(user.getAgencyId()!=null){
     SysAgency agency = agencyService.getAgency(user.getAgencyId());
     if(agency!=null){
      userContext.setSysAgency(agency);
     }
    }
    WebUtils.setSessionAttribute(request, "userContext", userContext);
    WebUtils.setSessionAttribute(request, USER_SESSION_KEY, createJsonUserContext(userContext));
   }
   arg1.setHeader("Access-Control-Allow-Origin", "*");//跨域
   arg1.getWriter().write(JSONObject.fromObject(loginResult).toString());
  } catch (Exception e) {
   e.printStackTrace();
   throw new LoginException("登录失败！", e);
  }
 }

同样的代码，只是不同的项目，所以出现此问题！