我已经把 body里的参数转换成gbk 编码格式了但是还是返回{"log_id": 5491831751295139032, "error_code": 282002, "error_msg": "input encoding error"}

代码里有转换，下边是代码,求解答

conn.setRequestProperty("Charset", "GBK");
// 设置文件类型:
conn.setRequestProperty("Content-Type","application/json;Charset=GBK");
// 设置接收类型否则返回415错误
conn.setRequestProperty("accept","*/*");//此处为暴力方法设置接受所有类型，以此来防范返回415;
conn.setRequestProperty("accept","application/json");