Is there a way to filter out all values that are bigger than the max value that can be stored in a Long using Stream API?
The current situation is that you can search in the frontend with a simple search bar after some customers by using their ID.
For example: 123456789, 10987654321. If you put a "separator" between these two IDs, everything works. But if you forget the "separator" my code is trying to parse 12345678910987654321 into a Long and I guess there is the problem.
That causes a NumberFormatException after trying to search. Is there a way to filter these numbers out that can't be parsed into a Long because they are too big?
String hyphen = "-";
String[] customerIds = bulkCustomerIdProperty.getValue()
.replaceAll("[^0-9]", hyphen)
.split(hyphen);
...
customerFilter.setCustomerIds(Arrays.asList(customerIds).stream()
.filter(n -> !n.isEmpty())
.map(n -> Long.valueOf(n)) // convert to Long
.collect(Collectors.toSet()));
You can either extract parsing into a separate method and wrap it with a try/catch, or use BigInteger to eliminate values that exceed the range of long.
Example with BigInteger:
Set<Long> result = Stream.of("", "12345", "9999999999999999999999999999")
.filter(n -> !n.isEmpty())
.map(BigInteger::new)
.filter(n -> n.compareTo(BigInteger.valueOf(Long.MAX_VALUE)) <= 0 &&
n.compareTo(BigInteger.valueOf(Long.MIN_VALUE)) >= 0)
.map(BigInteger::longValueExact) // convert to Long
.peek(System.out::println) // printing the output
.collect(Collectors.toSet());
Example with handling NumberFormatException in a separate method:
Set<Long> result = Stream.of("", "12345", "9999999999999999999999999999")
.filter(n -> !n.isEmpty())
.map(n -> safeParse(n))
.filter(OptionalLong::isPresent)
.map(OptionalLong::getAsLong) // extracting long primitive and boxing it into Long
.peek(System.out::println) // printing the output
.collect(Collectors.toSet());
public static OptionalLong safeParse(String candidate) {
try {
return OptionalLong.of(Long.parseLong(candidate));
} catch (NumberFormatException e) {
return OptionalLong.empty();
}
}
Output (from peek())
12345
Maybe you could add another filter like
.filter((n) -> { return new BigInteger(n).compareTo(new BigInteger(String.valueOf(Long.MAX_VALUE))) <= 0;})
You could also use a try/catch to throw an error when this happens and notify your frontend