首先，前台代码如下：
<form method="post" class="pageForm required-validate" onsubmit="return validateCallback(this, dialogAjaxDone)">
其次后台Java代码中设置回调参数
Struts2Utils.getResponse().getWriter().write("{"statusCode":"200","message":"成功","navTabId":"","rel":"","callbackType":"closeCurrent","forwardUrl":"","confirmMsg":""}");