恒星支付代码在Java中不起作用

Question

I have referred documentation on Stellar .

Then I have started to run the send payment and receiving payment code after creating an account in Java.

Send payment code is working , but receiving payment code got terminated. I have mentioned code below :

public class receivePayment {

public static void main(String args[]) {

    Server server = new Server("https://horizon-testnet.stellar.org");
    KeyPair account = KeyPair.fromAccountId("GC2BKLYOOYPDEFJKLKY6FNNRQMGFLVHJKQRGNSSRRGSMPGF32LHCQVGF");

    // Create an API call to query payments involving the account.
    PaymentsRequestBuilder paymentsRequest = server.payments().forAccount(account);

    // If some payments have already been handled, start the results from
    // the
    // last seen payment. (See below in `handlePayment` where it gets
    // saved.)
    /*
     * String lastToken = loadLastPagingToken(); if (lastToken != null) {
     * paymentsRequest.cursor(lastToken); }
     */

    // `stream` will send each recorded payment, one by one, then keep the
    // connection open and continue to send you new payments as they occur.
    paymentsRequest.stream(new EventListener<OperationResponse>() {
        @Override
        public void onEvent(OperationResponse payment) {
            // Record the paging token so we can start from here next time.
            // savePagingToken(payment.getPagingToken());

            // The payments stream includes both sent and received payments.
            // We only
            // want to process received payments here.
            if (payment instanceof PaymentOperationResponse) {
                if (((PaymentOperationResponse) payment).getTo().equals(account)) {
                    return;
                }

                String amount = ((PaymentOperationResponse) payment).getAmount();

                Asset asset = ((PaymentOperationResponse) payment).getAsset();
                String assetName;
                if (asset.equals(new AssetTypeNative())) {
                    assetName = "lumens";
                } else {
                    StringBuilder assetNameBuilder = new StringBuilder();
                    assetNameBuilder.append(((AssetTypeCreditAlphaNum) asset).getCode());
                    assetNameBuilder.append(":");
                    assetNameBuilder.append(((AssetTypeCreditAlphaNum) asset).getIssuer().getAccountId());
                    assetName = assetNameBuilder.toString();
                }

                StringBuilder output = new StringBuilder();
                output.append(amount);
                output.append(" ");
                output.append(assetName);
                output.append(" from ");
                output.append(((PaymentOperationResponse) payment).getFrom().getAccountId());
                System.out.println(output.toString());
            }

        }
    });
}

}

I don't understand why it gets terminated. If I checked the balance from my account URL, but shows me the sending-receiving result, but it is not showing result in Eclipse.

I have also referred below reference link and follow the answer but still it is not working.

Stellar payments query

Can anyone tell me how to run this code which continuously receive the payments and maintain the logs on console. ?

Answer 1

The thing is this is a streaming service, so if you just run the service in main method then it will obviously terminated while running in main method and the scope will go outside and EventListener will not be able to be executed. As you said you are using eclips,one thing you can do is instead of run try debug and insert a debugpoint at this Server server = new Server("https://horizon-testnet.stellar.org"); line and press F6 and go one by one line. While debugging Once it reaches the last line of the program then wait,don't run. You will see the data in the console. this way you will understand how the program is working. If you want to run it fast then use the code that I have added with the existing code. I have added two options. you can use any of this. This will display the output.

public class TestStellar2 {


      public static void main(String args[]) {

        Server server = new Server("https://horizon-testnet.stellar.org");
        KeyPair account = KeyPair.fromAccountId("GC2BKLYOOYPDEFJKLKY6FNNRQMGFLVHJKQRGNSSRRGSMPGF32LHCQVGF");

        PaymentsRequestBuilder paymentsRequest = server.payments().forAccount(account);


        paymentsRequest.stream(new EventListener <OperationResponse>(){
          @Override
          public void onEvent(OperationResponse payment) {

            if (payment instanceof PaymentOperationResponse) {
              if (((PaymentOperationResponse) payment).getTo().equals(account)) {
                return;
              }

              String amount = ((PaymentOperationResponse) payment).getAmount();

              Asset asset = ((PaymentOperationResponse) payment).getAsset();
              String assetName;
              if (asset.equals(new AssetTypeNative())) {
                assetName = "lumens";
              } else {
                StringBuilder assetNameBuilder = new StringBuilder();
                assetNameBuilder.append(((AssetTypeCreditAlphaNum) asset).getCode());
                assetNameBuilder.append(":");
                assetNameBuilder.append(((AssetTypeCreditAlphaNum) asset).getIssuer().getAccountId());
                assetName = assetNameBuilder.toString();
              }

              StringBuilder output = new StringBuilder();
              output.append(amount);
              output.append(" ");
              output.append(assetName);
              output.append(" from ");
              output.append(((PaymentOperationResponse) payment).getFrom().getAccountId());
              System.out.println(output.toString());
            }
          }
        }); 

        /**
         * option 1
         * 
         */
       /*try {
            System.in.read();
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }*/

        /**
         * option 2
         */
        try {
            Thread.currentThread().join();
        } catch (InterruptedException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

      }

    }

The output will look like below :

10.0000000 lumens from GC2BKLYOOYPDEFJKLKY6FNNRQMGFLVHJKQRGNSSRRGSMPGF32LHCQVGF many line like this