SpringMVC基于阻塞队列LinkedBlockingQueue的同步长轮询功能实现详解

/**
	 * 存储客户端（用户）提交的设置控制命令
	 */
	public final static BlockingQueue<Equipment> EQUIPMENT_CONTROL = new LinkedBlockingQueue<Equipment>();

/**
	 * 保存或更新设备接口
	 **/
	@RequestMapping("/save.do")
	@ResponseBody
	public void save(HttpServletRequest request, HttpServletResponse response) throws Exception {
		Personal personal = SecurityUtils.getPersonal(request);
		Long personalId = personal.getId();
		if (personalId == null) {
			outFailureJson(response, BaseCodeMessage.personal_10001);
			return;
		}
		//做你要做的事情
		//向队列中插入消息
		ConstantDict.EQUIPMENT_CONTROL.put(entity);
		//输出响应内容
		this.outResultJson(response, "success", "Equipment", entity);
	}

/**
	 * 控制设置状态接口_供网关调用 这是一个提供长轮询的方法，网关通过长轮询来即时获得命令信息
	 * 
	 * @author lipw
	 * @date 2017年8月30日下午3:31:59
	 * @param request
	 * @param response
	 * @throws Exception
	 */
	@RequestMapping("/ctrlgw.do")
	@ResponseBody
	public void controlgw(HttpServletRequest request, HttpServletResponse response) throws Exception {
		Personal personal = SecurityUtils.getPersonal(request);
		Long personalId = personal.getId();
		if (personalId == null) {
			outFailureJson(response, BaseCodeMessage.personal_10001);
			return;
		}
		Long familyId = personal.getFamilyId();
		if (familyId == null) {
			outFailureJson(response, "2", "尚未分配家庭编号！");
			return;
		}
		Equipment equipment = null;
		while (true) {
			equipment = ConstantDict.EQUIPMENT_CONTROL.poll(5000, TimeUnit.MILLISECONDS);
			if (equipment != null) {
				if (familyId.equals(equipment.getFamilyId())) {
					System.out.println("从队列取走一个元素，队列剩余" + ConstantDict.EQUIPMENT_CONTROL.size() + "个元素");
					break;
				} else {
					// 不属于自己，再放回队列
					ConstantDict.EQUIPMENT_CONTROL.put(equipment);
				}
			}
			Thread.sleep(100);
		}
		this.outResultJson(response, "success", "equipment", equipment);
	}

<div id="divCommand" style="width:98%; min-height:100px; border:1px solid #888;"></div>
<script src="${ctx}/static/script/jquery-1.10.2.min.js"></script>
<script type="text/javascript">
var successCount = 0;
function loadCommand(){
	$.ajax({  
        url:"${ctx}/xxx/ctrlgw.do?token=xxx&t=" + Date.now(),  
        type:"get",  
        data:{},
        dataType:"json",
        success:function(data)  
        {  
            if(data != null && data!=""){
            	successCount++;
            	$("#divCommand").append(successCount + ", ");
            }
            loadCommand(); //成功后继续回调
        },error:function(data){
        	if(data != null && data!=""){
            	    $("#divCommand").append(data.statusText);
                }
        	if (data.statusText == "timeout"){
        	    loadCommand(); //超时回调
        	}
        }
    });
}
$(document).ready(function(){
    loadCommand();
});
</script>