import java.math.BigDecimal;
import com.braintreegateway.*;

public class BraintreeExample {
    public static void main(String[] args) {
        BraintreeGateway gateway = new BraintreeGateway(
            Environment.SANDBOX,
            "the_merchant_id",
            "the_public_key",
            "the_private_key"
        );

        TransactionRequest request = new TransactionRequest().
            amount(new BigDecimal("1000.00")).
            creditCard().
                number("4111111111111111").
                expirationDate("05/2009").
                done();

        Result<Transaction> result = gateway.transaction().sale(request);

        if (result.isSuccess()) {
            Transaction transaction = result.getTarget();
            System.out.println("Success!: " + transaction.getId());
        } else if (result.getTransaction() != null) {
            Transaction transaction = result.getTransaction();
            System.out.println("Error processing transaction:");
            System.out.println("  Status: " + transaction.getStatus());
            System.out.println("  Code: " + transaction.getProcessorResponseCode());
            System.out.println("  Text: " + transaction.getProcessorResponseText());
        } else {
            for (ValidationError error : result.getErrors().getAllDeepValidationErrors()) {
               System.out.println("Attribute: " + error.getAttribute());
               System.out.println("  Code: " + error.getCode());
               System.out.println("  Message: " + error.getMessage());
            }
        }
    }
}

 mvn package

 Maven Central, which should be enabled by default. No additional repositories are required.

<dependency>
  <groupId>com.braintreepayments.gateway</groupId>
  <artifactId>braintree-java</artifactId>
  <version>PUT VERSION NUMBER HERE</version>
</dependency>