获取请求头
获取请求头信息使用 @HeaderParameter 注解:
@MappingTo("/helloAction.do")
public class HelloAction {
    public void execute(@HeaderParameter("ajaxTo") boolean ajaxTo) {
        ...
    }
}
$.ajax({
    beforeSend: function (request) {
        request.setRequestHeader("ajaxTo", "true");
    },
    url: "/helloAcrion.do",
    data: formData,
    dataType: 'json',
    async: true,
    success: function (result) {
        ...
    },
    error: function (result) {
        ...
    }
});