Ajax 請求session過期的統一處理

public class LoginInterceptor extends HandlerInterceptorAdapter {

	@SuppressWarnings("unused")
	private static final Logger log = Logger.getLogger(LoginInterceptor.class);
	
	@Override
	public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler)
			throws Exception { 
//		log.info("URL="+request.getRequestURL().toString());
		Object obj = request.getSession().getAttribute(SecurityConstants.LOGIN_USER);
		if (null == obj) {  
        	if (WebUtil.isAjaxRequest(request)){ 
	            response.setHeader("sessionstatus", "timeout");  
	        }else{
	        	response.sendRedirect(request.getContextPath()+"/usr/login");
	        }  
        	return false;
        }  
		return super.preHandle(request, response, handler);
	}
}

　　

public static boolean isAjaxRequest(HttpServletRequest request){ 
		boolean result = false;
		
	　　　　 String headerX = request.getHeader("X-Requested-With");			
	        return headerX != null  && headerX.equalsIgnoreCase("XMLHttpRequest");			
		
	}

　　

/**
 * 設置未來(全局)的AJAX請求默認選項
 * 主要設置了AJAX請求遇到Session過期的情況
 */
$.ajaxSetup({
    type: 'POST',
    complete: function(xhr,status) {
        var sessionStatus = xhr.getResponseHeader('sessionstatus');
        if(sessionStatus == 'timeout') {
            var top = getTopWinow();
            var yes = confirm('由於您長時間沒有操作, session已過期, 請重新登錄.');
            if (yes) {
                top.location.href = '/skynk/index.html';            
            }
        }
    }
});

/**
 * 在頁面中任何嵌套層次的窗口中獲取頂層窗口
 * @return 當前頁面的頂層窗口對象
 */
function getTopWinow(){
    var p = window;
    while(p != p.parent){
        p = p.parent;
    }
    return p;
}