前端代码(html5.html)：
<html> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <head><title>消息推送</title> <script type="text/javascript"> var source = new EventSource("fail.jsp"); source.onmessage=function(event) { document.getElementById("result").innerHTML += event.data + "<br />"; }; source.onerror = function(event){ alert("onerror"); }; source.onopen = function(event){ alert("onopen"); }; </script> </head> <body> <div id="result">123</div> </body> </html>
后台代码(fail.jsp)：
<% response.setHeader("Content-Type","text/event-stream"); response.setHeader("Cache-Control","no-cache"); out.println("data: "+new java.util.Date(System.currentTimeMillis()).toString()); out.println(); out.flush(); %>
注意：后台代码解释：
(1)把报头"Content-Type"设置为"text/event-stream"
(2)规定页面不能缓存
(3)输出发送的数据始终以："data: "开头（数据一定要以两个换行符为结束）
(4)向客户刷出数据