Java : Supplier with Examples
Supplier (Java SE 21 & JDK 21) with Examples.
You will find code examples on most Supplier<T> methods.
Summary
Represents a supplier of results.
final var opt1 = Stream.of("abcd", "efgh").findFirst();
final var opt2 = Stream.<String>empty().findFirst();
final var other = new Supplier<String>() {
@Override
public String get() {
return "XYZ";
}
};
System.out.println(opt1.orElseGet(other)); // abcd
System.out.println(opt2.orElseGet(other)); // XYZ
// An example with a lambda expression.
final var opt = Stream.empty().findFirst();
System.out.println(opt.orElseGet(() -> "XYZ")); // XYZ
Methods
T get ()
Gets a result.
final var supplier = new Supplier<String>() {
@Override
public String get() {
return "abcd";
}
};
System.out.println(supplier.get()); // abcd
final var supplier = new Supplier<String>() {
int count = 0;
@Override
public String get() {
count++;
return "a".repeat(count);
}
};
final var stream = Stream.generate(supplier);
final var ret = stream.limit(4).toList();
System.out.println(ret); // [a, aa, aaa, aaaa]
// An example with a lambda expression.
final var opt = Stream.empty().findFirst();
System.out.println(opt.orElseGet(() -> "XYZ")); // XYZ