使用java实现极光推送总是推送不了.出现{}的错误.大神帮个忙啊

{}
    at cn.jpush.api.common.connection.NativeHttpClient._doRequest(NativeHttpClient.java:228)
    at cn.jpush.api.common.connection.NativeHttpClient.doRequest(NativeHttpClient.java:93)
    at cn.jpush.api.common.connection.NativeHttpClient.sendPost(NativeHttpClient.java:80)
    at cn.jpush.api.push.PushClient.sendPush(PushClient.java:119)
    at cn.jpush.api.JPushClient.sendPush(JPushClient.java:141)
    at cn.lj.pushTest.Main.push(Main.java:44)
    at cn.lj.pushTest.Main.main(Main.java:30)