Java Streams return a specific class

Question

I have a list which contains many token requestors but ID is unique and filter will returns just one object.

for (TokenRequestor requestor : tokenRequestorList) {
    if (requestor.getId().equals(tokenRequestor.getId())) {
        System.out.println("This object is unique!");
    }
}

I try write this code in Java 8:

tokenRequestorList.stream().filter(tr -> tr.getId()
        .equals(tokenRequestor.getId())).collect(Collectors.toList());

How I can filter to return a TokenRequestor? This list will be contain 1 element.

E.g:

TokenRequestor myObject = tokenRequestorList.stream()
        .filter(tr -> tr.getId().equals(tokenRequestor.getId()))....;

[findFirst](https://docs.oracle.com/javase/8/docs/api/java/util/stream/Stream.html#findFirst--) !? — luk2302, May 29 '17 at 18:58
Possible duplicate of [Java 8 find first element by predicate](https://stackoverflow.com/questions/23696317/java-8-find-first-element-by-predicate) — Didier L, May 30 '17 at 08:01

score 3 · Accepted Answer · answered May 29 '17 at 18:58

tokenRequestorList.stream()
    .filter(tr -> tr.getId().equals(tokenRequestor.getId()))
    .findAny()
    .orElse(null);

This will return any TokenRequestor instance matching the filter (in your case it will be unique), or null is nothing matches the filter.

Java Streams return a specific class

1 Answers1