使用http statusCode请求失败：422，异常：org.apache.http.client.HttpResponseException：不可处理的实体

I'm new to the group and debutant on the Android Development, month I work on a payment by paypal module, but I get an error that I'm having trouble solving. error message:![enter image description here][1]I'm new to the group and debutant on the Androi