How to integrate paypal rest api in spring JPA application. ERROR CODE 400

Question

As per the java SDK provided here , I created a new project and tried to integrate the codes to make paypal api calls. But when I run the application, it gives me error as :-

Error code : 401 with response : Server returned HTTP response code: 401 for URL: https://api.sandbox.paypal.com/v1/payments/payment

Here is my controller class

package com.main.controller;

public class PaymentController{ 

@RequestMapping(method = RequestMethod.POST, produces = "application/JSON")

public Payment getString(){

    InputStream is = PaymentController.class
            .getResourceAsStream("/sdk_config.properties");
    try {
        PayPalResource.initConfig(is);
        System.out.println("initiialization done");
    } catch (PayPalRESTException e) {
        System.out.println("Paypal Rest Exception : " + e.getMessage());
    }

    Map<String, String > map = new HashMap<String, String>();
    map.put("mode", "sandbox");
    String clientID = "AYDNebhrsuqiUKPU_ab-tCvGGVkzaxw2y4bIJFIl4rMuCW..........................";
    String clientSecret="ENgjkFRgy1yGhal0aobwdF8kLNglkDaDeDItLN-lgQJZV4W1FpNQ27g3FC...............";

    try {
        accessToken = new OAuthTokenCredential(clientID, clientSecret,map).getAccessToken();
    } catch (PayPalRESTException e) {
        // TODO Auto-generated catch block
        System.out.println("Cannot make the OAuthentication :" + e.getMessage());
    }

    Payment payment = createPayment();

    return payment;
}

public Payment createPayment(){

    Address billingAddress = new Address();
    billingAddress.setCity("Johnstown");
    billingAddress.setCountryCode("US");
    billingAddress.setLine1("52 N Main ST");
    billingAddress.setPostalCode("43210");
    billingAddress.setState("OH");

    CreditCard creditCard = new CreditCard();        
    creditCard.setBillingAddress(billingAddress);
    creditCard.setCvv2(111);
    creditCard.setExpireMonth(11);
    creditCard.setExpireYear(2018);
    creditCard.setFirstName("Joe");
    creditCard.setLastName("Shopper");
    creditCard.setNumber("5500005555555559");
    creditCard.setType("mastercard");

    Details details = new Details();
    details.setShipping("1");
    details.setSubtotal("5");
    details.setTax("1");

    Amount amount = new Amount();
    amount.setCurrency("USD");
    amount.setTotal("7");
    amount.setDetails(details);

    Transaction transaction = new Transaction();
    transaction.setAmount(amount);
    transaction
            .setDescription("This is the payment transaction description.");


    List<Transaction> transactions = new ArrayList<Transaction>();
    transactions.add(transaction);

    FundingInstrument fundingInstrument = new FundingInstrument();
    fundingInstrument.setCreditCard(creditCard);  


    List<FundingInstrument> fundingInstrumentList = new ArrayList<FundingInstrument>();
    fundingInstrumentList.add(fundingInstrument);

    Payer payer = new Payer();
    payer.setFundingInstruments(fundingInstrumentList);
    payer.setPaymentMethod("credit_card");

    Payment payment = new Payment();
    payment.setIntent("sale");
    payment.setPayer(payer);
    payment.setTransactions(transactions);
    Payment createdPayment = null;
    try {
        String accessToken = GenerateAccessToken.getAccessToken();

        String realAccessToken = "A101.kPIsO7eGXhg420XIjnZmPboCS27CeDF6TZjVfGR31f6ja1IotK3e6U-E_k9MwOO5.....";


        /*
         * String requestId = Long.toString(System.nanoTime(); APIContext
         * apiContext = new APIContext(accessToken, requestId ));
         */

        createdPayment = payment.create(apiContext);

        System.out.println("Created payment with id = " + createdPayment.getId()
        + " and status = " + createdPayment.getState());
    } catch (PayPalRESTException e) {
        System.out.println("Cannot make the payment from here: " + e.getMessage());
    }
    return createdPayment;
}

}

UPDATE :- I have added client_id and secret authentication credentials and now I get is 400 error which is Validation Error

Answer 1

401 is Unauthorized. So, at first you have to authorized and create authorized token. Here is example how to create you first call.

Make a /token call using your application's OAuth keys for the basic authentication values (the keys are the values of your client_id and secret). In the request body, set grant_type to client_credentials. When you run the command, PayPal generates and returns a new access token.

Add your token to your payment which you want to create.

Look at this line in this Sample: https://github.com/paypal/PayPal-Java-SDK/blob/master/rest-api-sample/src/main/java/com/paypal/api/sample/FuturePaymentSample.java#L62

So use Sandbox and something like that:

Map<String, String> configurationMap = new HashMap<String, String>();
            configurationMap.put("mode", "sandbox");
            APIContext apiContext = new APIContext();
            apiContext.setConfigurationMap(configurationMap);
            tokeninfo = Tokeninfo.createFromAuthorizationCodeForFpp(apiContext, params);
            tokeninfo.setAccessToken(tokeninfo.getTokenType() + " " + tokeninfo.getAccessToken());

After that you should be able to call tokeninfo.getAccessToken() for creating payment.