java paypal api call certificate is requierd?

Question

I am using Java & paypal express checkout & DoDirectPayment, i see there are two options either by signature given by paypal sandbox merchant account or signature given by paypal sandbox merchant account.

Do i need any certificate if i am using "signature" string ?

Answer 1

At SandBox, those two Credentials (generated at SandBox primary account and test account) are same. It is for your convenience.

Do i need any certificate if i am using "signature" string? No, you do not need certificate if you use Signature. You cannot even create both in single paypal account. API Signature is new way of accessing API; even PayPal recommands using API Signature.