Saturday, August 7, 2010

PayPal Mass Payments using HttpClient 4

Here's another PayPal tip. The PayPal Mass Payments feature allows anyone with a Premier or Business account to send multiple payments instantly—saving time, money and the hassle of having to individually send funds to every payment recipient.

In this tip I will show you how to make a mass payment using the apache httpclient library (, version 4.

First we define some constants we'll need in the code:

private NumberFormat paypalNumberFormat = new DecimalFormat("0.00", new DecimalFormatSymbols(Locale.US));
private static final String PAYPAL_URL = ""; //Remove the ".sandbox" if you want to use the live environment
private static final String PAYPAL_USER = "username";
private static final String PAYPAL_PASSWORD = "password";
private static final String PAYPAL_SIGNATURE = "signature";

Here's the code to make the actual call:

HttpClient client = new DefaultHttpClient();
HttpPost post = new HttpPost(PAYPAL_URL);
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("USER", PAYPAL_USER));
params.add(new BasicNameValuePair("PWD", PAYPAL_PASSWORD));
params.add(new BasicNameValuePair("SIGNATURE", PAYPAL_SIGNATURE));
params.add(new BasicNameValuePair("VERSION", "2.3"));
params.add(new BasicNameValuePair("METHOD", "MassPay"));
params.add(new BasicNameValuePair("RECEIVERTYPE", "EmailAddress"));
params.add(new BasicNameValuePair("L_EMAIL0", email));
params.add(new BasicNameValuePair("L_AMT0", paypalNumberFormat.format(amountToSend)));
params.add(new BasicNameValuePair("CURRENCYCODE", "USD"));
post.setEntity(new UrlEncodedFormEntity(params));
HttpResponse response = client.execute(post);

This sample will send 1 payment to the PayPal account in the email variable and with the amount in the amountToSend variable. The parameters are called L_EMAIL0 and L_AMT0. Since this is the mass payments API, you can send more than one payment. To do so, just add 2 new parameters for each payment you want to make: L_EMAILx for the PayPal account you want to send the money to and L_AMTx for the amount you want to transfer. x is a number from 0 to 255, making the maximum number of simultaneous payments you can make 256.

PayPal sends back a couple of parameters. You will probably want to check the "ACK" parameter, which tells you if your call succeeded. See for an overview of the parameters and their values returned by PayPal. Here is a way to parse the response:

private Map<String, String> parseResponse(HttpResponse response) throws IllegalStateException, IOException {
Map<String, String> map = new HashMap<String, String>();
String responseStr = getResponseContent(response);
List<NameValuePair> responseParams = new ArrayList<NameValuePair>();
URLEncodedUtils.parse(responseParams, new Scanner(responseStr), "UTF-8");
for (NameValuePair nvp : responseParams) {
map.put(nvp.getName(), nvp.getValue());
return map;

private String getResponseContent(HttpResponse response) throws IOException, IllegalStateException {
InputStream is = response.getEntity().getContent();
BufferedReader br = new BufferedReader(new InputStreamReader(is));
String result = "";
String line = null;
while ((line = br.readLine()) != null) {
result += line;
return result;

You can call it like this:

Map<String, String> responseParams = parseResponse(response);
String ack = responseParams.get("ACK");
if (ack != null && ack.indexOf("Success") >= 0) {
//Do something
} else {
//Do something else