public static <T> Collection<Collection<T>> split(Collection<T> bigCollection, int maxBatchSize) {
Collection<Collection<T>> result = new ArrayList<Collection<T>>();
ArrayList<T> currentBatch = null;
for (T t : bigCollection) {
if (currentBatch == null) {
currentBatch = new ArrayList<T>();
} else if (currentBatch.size() >= maxBatchSize) {
result.add(currentBatch);
currentBatch = new ArrayList<T>();
}
currentBatch.add(t);
}
if (currentBatch != null) {
result.add(currentBatch);
}
return result;
}
Voilà comment nous l'utilisons (en supposant des e-mails un grand ArrayList d'adresses e-mail:
Collection<Collection<String>> emailBatches = Helper.split(emails, 500);
for (Collection<String> emailBatch : emailBatches) {
sendEmails(emailBatch);
// do something else...
// and something else ...
}
}
où emailBatch serait itérer sur la collection comme ceci:
private static void sendEmails(Collection<String> emailBatch){
for(String email: emailBatch){
// send email code here.
}
}
Où est le code – Jeffrey