jsp页面:
$(document).ready(function() {
setInterval(function myTimer()
{
//alert(\'a\');
getViews();
},1000);
});
//播放
function getViews(){
$.ajax({
\'url\':\"${pageContext.request.contextPath}/video/getVideos.action?r=\"+Math.random()+\"&open=1\",
\'data\': \'\',
\'dataType\': \'json\',
\'type\': \'get\',
\'error\': function(data){
alert(\"error\");
return false;
},
\'success\': function(data) {
if(null != data && \'\' != data){
//alert(data.updateFlag);
if(data.updateFlag==0){//如果data.updateFlag=0 不刷新
//alert(\"data.updateFlag=0\");
}
else{
if(data.videoIds != null && data.videoIds != \"\"){
var listIds=data.videoIds;
var i=0;
for(;i<listIds.length;++i){
//alert(\"show:\"+i+\"id=:\"+listIds[i]);
showView(listIds[i],i);//播放
}
for(var j=listIds.length;j<9;++j){
//alert(\"Stop:\"+j);
StopPlayVideo(j);
}
}
}
}
}
});
}
此处由于此代码实现的功能是通过ajax定时访问后台Hashtable,所以为了是系统区别url不同、ajax返回值不同,特意在url后加上r=+Math.random()
java后台处理方法:
/**
* 双服务器九宫格显示
*
* @return
*/
@Action(value = \"getVideos\" ,results={
@Result(name = SUCCESS,location=\"videos2.jsp\")
})
public String getVideos() {
if (open == 301) {
return SUCCESS;
} else {
try {
VideoHashTable videoHashTable = VideoHashTable.getInstance();
Hashtable<Long, Long> hashTable = videoHashTable.getRht();
Map map = new HashMap<String, List<Long>>();
if (videoHashTable.isUpdateFlag() == true) {
Enumeration en = hashTable.keys();
videoIds = new ArrayList<Long>();
while (en.hasMoreElements()) {
Long key = (Long) en.nextElement();
// vth.get(key);
videoIds.add(key);
}
map.put(\"videoIds\", videoIds);
map.put(\"updateFlag\", 1L);
videoHashTable.setUpdateFlag(false);
System.out.println(\"getVideos:\" + videoIds);
SendMessage.sendObject(map);
} else {
map.put(\"updateFlag\", 0L);
SendMessage.sendObject(map);
}
} catch (Exception e) {
e.printStackTrace();
}
return null;
}
}
关键要把传到jsp的页面存到map中,在通过json传值。
SendMessage.sendObject(map)方法所在类及方法:
package com.supcon.honcomb.utils;
import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.http.HttpServletResponse;
import org.apache.http.HttpResponse;
import org.apache.struts2.ServletActionContext;
public class SendMessage {
public static void sendMessage(String responseText){
try {
PrintWriter out = ServletActionContext.getResponse().getWriter();
out.print(responseText);
out.close();
} catch (IOException e) {
e.printStackTrace();
}
}
public static void sendObject(Object obj) throws Exception {
PrintWriter pw;
String rtn = \"\";
HttpServletResponse response = ServletActionContext.getResponse();
response.setContentType(\"text/html\");
response.setCharacterEncoding(\"UTF-8\");
rtn = JsonUtil.JsonFromObject(obj);
pw = response.getWriter();
pw.write(rtn);
pw.flush();
pw.close();
}
}