Answers for "how to find if particular set of files exists in a folder in python"

java create file if not exists

String yourFile = "YourFile.txt";
String yourContent = "YourContent"

File tmpDir = new File(yourFile);
boolean exists = tmpDir.exists();

if(!exists) {
	FileOutputStream fos = new FileOutputStream(yourFile);
	fos.write(yourContent.getBytes());
	fos.flush();
	fos.close();
}

java find if element of list in present in another list

list1.stream()
   .map(Object1::getProperty)
   .anyMatch(
     list2.stream()
       .map(Object2::getProperty)
       .collect(toSet())
       ::contains)

// Example with predicate
Predicate<Object> notInList1 = object -> list1.stream().noneMatch(object::equals);
List<Object> missingInList1 = list2.stream().filter(notInList1).collect(Collectors.toList());