贝宝REST API -沙箱返回401的API请求但成功的访问令牌。

I am using the PayPal REST API in Java to make a request to the testing (sandbox) servers for an access token, which succeeds, and then sending that access token back to the same sandbox servers for a Payment which fails with a 401 Not Authorized.I am using the PayPal REST API in Java to make