Can be convert following java code to Lambda expression?

Question

I need to know following code can be convert to lamda expression.

private class K<D extends BaseDose<I>, I extends DoseInstance>
    implements Predicate<Prescription<D, I>>
  {
    @Override
    public boolean test(final Prescription<D, I> input)
    {
      return DepositType.DATE == input.getBaseDeposit().getDepositType();
    }
  }

Predicate<Prescription<D, I>> is a functional interface, so yes. The whole thing can probably be written as input -> DepositType.DATE == input.getBaseDeposit().getDepositType(). — ernest_k
– ernest_k, Commented Jul 16, 2019 at 6:48

Eran · Accepted Answer · 2019-07-16 07:39:35Z

4

Instead of creating a class (your K class) that implements Predicate<Prescription<D, I>>, you can assign a lambda expression to a Predicate variable.

For example:

Predicate<Prescription<BaseDose<DoseInstance>, DoseInstance>> pred =
    p -> DepositType.DATE == p.getBaseDeposit().getDepositType();

If you need a lambda expression with multiple statements, you can write:

Predicate<Prescription<BaseDose<DoseInstance>, DoseInstance>> pred =
    p -> {
        final SigningStatus signingStatus = p.getSigningStatus();
        return !p.isReplacedByLatest() && SigningStatus.INVALIDATED.equals(signingStatus);
    };

though this can be simplified to a single statement:

Predicate<Prescription<BaseDose<DoseInstance>, DoseInstance>> pred =
    p -> !p.isReplacedByLatest() && SigningStatus.INVALIDATED.equals(p.getSigningStatus());

edited Jul 16, 2019 at 7:39

answered Jul 16, 2019 at 6:54

Eran

395k57 gold badges726 silver badges793 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

davidxxx Over a year ago

For the OP : Predicate<Prescription<?>> should also work if Prescription is bounded with BaseDose and DoseInstance, which would make sense.

uma Over a year ago

@Eran 'inside test , like this code ' final SigningStatus signingStatus = input.getSigningStatus(); return !input.isReplacedByLatest() && SigningStatus.INVALIDATED.equals(signingStatus);can aslo convert to lambda?

Collectives™ on Stack Overflow

Can be convert following java code to Lambda expression?

1 Answer 1

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related