dwr 推送消息

dwr + spring  實時推送消息，通過網絡技術學習，做了個小功能，總結如下：

1、下載dwr.jar

官網地址：http://directwebremoting.org/dwr/downloads/

下載最新版本v3.0

2、導入jar

   

3、配置web.xml

<!-- DWR配置 START -->
<servlet>
	<description>This is the description of my J2EE component</description>
	<display-name>This is the display name of my J2EE component</display-name>
	
	<servlet-name>DWRServlet</servlet-name>
	<servlet-class>org.directwebremoting.servlet.DwrServlet</servlet-class>
	<!--commet 方式-->
	<init-param>
		<param-name>activeReverseAjaxEnabled</param-name>
		<param-value>true</param-value>
	</init-param>
	<!--測試環境下,需要開啓debug模式,線上環境需要關閉-->  
	<init-param>
		<param-name>debug</param-name>
		<param-value>false</param-value>
	</init-param>
	<!--允許跨域-->
	<init-param>
		<param-name>crossDomainSessionSecurity</param-name>
		<param-value>false</param-value>
	</init-param>
	<!--允許腳本標籤遠程--> 
	<init-param>
		<param-name>allowScriptTagRemoting</param-name>
		<param-value>true</param-value>
	</init-param>
</servlet>

<servlet-mapping>
	<servlet-name>DWRServlet</servlet-name>
	<url-pattern>/dwr/*</url-pattern>
</servlet-mapping> 

<!-- DWR配置 END -->

4、由Spring管理dwr

配置applicationContext-common.xml 

<!--由spring管理dwr   -->
<bean id="deviceInfo" class="com.dc.rcms.DWRDeviceInfoStatus"></bean>

5、頁面引用以下js

<!--dwr消息推送 -->
<script type="text/javascript" src="dwr/engine.js"></script>
<script type="text/javascript" src="dwr/util.js"></script>

並且頁面 初始化，加

$(function(){    
    dwr.engine.setActiveReverseAjax(true);  
    dwr.engine.setNotifyServerOnPageUnload(true);
});

6、後臺直接要推送的內容

public DWRDeviceInfoStatus(){
	//定時向前臺推送設備信息
	Timer timer = new Timer();
	timer.schedule(new TimerTask() {
		@Override
		public void run() {
		<span style="white-space:pre">	</span>try{
				ServerContext serverContext = ServerContextFactory.get();
				Container container = serverContext.getContainer();
				ScriptSessionManager manager = container.getBean(ScriptSessionManager.class);
				Collection sessions = manager.getAllScriptSessions();
				if(sessions.size() == 0 ){
					return;
				}
				//得到設備部位信息狀態數量
				Util util = new Util(sessions);
				List<SEntity> list=baseDao.search("select count(id) as allnum,sum(case when status=1 then 1 end) as gznum,sum(case when status=0 then 1 end) as zcnum from rcms_device ",null);
				if(list!=null && list.size()>0){
					SEntity entity=list.get(0);
					String jsonStr="{\"allnum\":"+repaceNull(entity.getValueAsString("allnum"))
							+",\"gznum\":"+repaceNull(entity.getValueAsString("gznum"))
							+",\"zcnum\":"+repaceNull(entity.getValueAsString("zcnum"))+"}";
					util.addFunctionCall("showDeviceInfo", jsonStr);
				}
				//得到所有故障點信息
				Util utilgzd = new Util(sessions);
				List<SEntity> gzlist=baseDao.search("select device_code,count(id) n from rcms_device where status =1 group by device_code order by device_code", null);
				if(gzlist!=null && gzlist.size()>0){
					String gzdjsonStr="[";
					for(int i=0;i<gzlist.size();i++){
						SEntity gzdentity=gzlist.get(i);
						gzdjsonStr += "{";
						gzdjsonStr +="\"device_code\":\""+repaceNull(gzdentity.getValueAsString("DEVICE_CODE"))+"\",";
						gzdjsonStr +="\"gzdnum\":\""+repaceNull(gzdentity.getValueAsString("n"))+"\"";
						gzdjsonStr +="},";
					}
					gzdjsonStr = gzdjsonStr.substring(0,gzdjsonStr.length()-1);
					gzdjsonStr = gzdjsonStr+"]" ;
					utilgzd.addFunctionCall("showDeviceGzdInfo", gzdjsonStr);
				}
				
			}catch(Exception e){
				
			}
		}
	}, 10*1000, 1000*3);
	
}	

7、頁面接收後臺推送的消息

腳本處理

/* 後臺自動推送設備信息 */
//顯示設備正常與否信息
function showDeviceInfo(data){
	var jsonstr = eval( "(" + data + ")" );
	if(jsonstr!=null){
		$("#bottomcount").html("<p style=\"margin-left: 20px;margin-top: 20px; font-size: 16px;\">共<span id=\"allnum\" style=\"margin-left: 10px;margin-right: 10px;\">"+jsonstr.allnum+"</span>個   正常<span id=\"zcnum\" style=\"margin-left: 10px;margin-right: 10px;\"><a class=\"icon\" target=\"dialog\" rel=\"main\" title=\"設備部位的正常數量\" width=\"850\" height=\"500\" οnclick=\"getsitezc_gznum(0);\"><font color=\"green\">"+jsonstr.zcnum+"</font></a></span>個   故障<span id=\"gznum\" style=\"margin-left: 10px;margin-right: 10px;\"><a class=\"icon\" target=\"dialog\" rel=\"main\" title=\"設備部位碼的故障數量\" width=\"850\" height=\"500\"οnclick=\"getsitezc_gznum(1);\"><font color=\"red\">"+jsonstr.gznum+"</font></a></span>個</p>");
	}
}
//顯示所有故障點信息
function showDeviceGzdInfo(data){
	var gzdjsonstr = eval( "(" + data + ")" );
	if(gzdjsonstr!=null){
		$("#gzdcount").html("<ul>");
		for(var i=0; i<gzdjsonstr.length; i++) { 
			$("#gzdcount").append("<a target=\"dialog\" rel=\"main\" title=\"設備部位的故障點數量\" width=\"850\" height=\"500\" οnclick=\"getsitegzdnum('"+gzdjsonstr[i].device_code+"');\"><li style=\"list-style-type:none;\"><img alt=\"警示\" src=\"img/warning.png\"/><span id=\"gzsnum\" style=\"margin-left: 5px;margin-top: 20px; font-size: 14px;\">"+gzdjsonstr[i].device_code+"  (  故障  <span style=\"margin-left: 5px;margin-right: 5px;margin-top: 10px;\"><font color=\"red\" >"+gzdjsonstr[i].gzdnum + "</font></span>個)</span></li></a></ul>");
		}
	}
	isfirst=2;
}

頁面如下

至此，大功告成。。。