//构建 请求报文，数据为JSON格式
StringBuilder body = new StringBuilder("{");
body.append(String.format("\"ta\":\"%s\"", ta));
body.append(String.format(",\"ab\":\"%s\"", ab));
body.append(String.format(",\"timestamp\":%d", timestamp));
body.append("}");
String bodyString = body.toString();
显示出来的就是
{"ta":"hdfhondd","ab":"dhfjkdj","timestamp":21546121465}
扩展：
//当前服务器的时间戳,注意必须是UTC时间 long timestamp = System.currentTimeMillis();