Hi, I'm new to square but not credit card processing.  I'm currently using Authorize.net's Advanced Integration Method (AIM) to charge cards in an eCommerce application from a back end server.  Is there an example of how to integrate Square into a back end system using Java? 

ANet uses code such as:

    import net.authorize.*;
    

    import net.authorize.aim.*;

    Merchant  merchant_ = Merchant.createMerchant(Environment.SANDBOX, apiLoginID, transactionKey);

   Transaction anetTrans = merchant_.createAIMTransaction(anetTransType, new BigDecimal(ccrTrans.amount()));
      
    Result<Transaction> result = (Result<Transaction>) merchant_.postTransaction(anetTrans);