我用定时推送任务为什么alert字段输入中文会报参数错误

这个是推送的内容{"enabled":true,"trigger":{"single":{"time":"2016-04-11 20:25:00"}},"name":"ssss","push":{"platform":"all","audience":"all","notification":{"alert":"达到是是是是少时诵诗书","extras":{"URL":"http://www.baidu.com"}},"options":{"time_to_live":60}}}

推送的头
connection.setDoOutput(true) ;
connection.setDoInput(true);
connection.setRequestMethod("POST");
connection.setUseCaches(false);
connection.setInstanceFollowRedirects(true);
connection.setRequestProperty("Content-Type","application/json");
connection.setRequestProperty("Accept-Charset","utf-8");
输入中文就是不对，英文可以