var activityId = "${activityId}";
var processKey = activityId.substr(0,activityId.indexOf(":"));
var activityKey = activityId.substr(activityId.indexOf(":")+1,activityId.length-1);
js截取字符串
原文：http://www.cnblogs.com/samwang88/p/47872f6697c3a19f9eabf45988098018.html
