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Tag: java-8

Spring deserializes a LocalDate in a @RequestBody differently from one in a @RequestParam – why, and can they be the same?

QUESTION: Spring appears to use different deserialization methods for LocalDate depending on whether it appears in a @RequestBody or a request @ReqestParam – is this correct, and if so, is there a way to configure them to be the same throughout an application? BACKGROUND: In my @RestController, I have two methods – one GET, and one POST. The GET expects

What is the equivalent way to do Ordering.lexicographical() in Java 8 Comparator?

Is there a way to implement Ordering.lexicographical() with Java 8 Comparator? Comparator.thenCompare seems to be limited in this Answer Seemingly not, no. As a result, Guava still provides this functionality, but in the new class Comparators: https://guava.dev/releases/snapshot/api/docs/com/google/common/collect/Comparators.html#lexicographical(java.util.Comparator). Note that Guava generally does a good job telling you whether and how to migrate off of it to new Java features, so

extract list inside a list as a single list

I’ve a two POJOs, Sample code below Controller class This returns me a list of the list: but what I want is a single list like How can I do that with Java 8 streams? I’ve tried flatMap also, but that doesn’t go well with the Object datatype of entries. Answer Consider a List<String> as a field entries in the

When should I use streams?

I just came across a question when using a List and its stream() method. While I know how to use them, I’m not quite sure about when to use them. For example, I have a list, containing various paths to different locations. Now, I’d like to check whether a single, given path contains any of the paths specified in the

“Double” composition with CompletableFuture

I’m trying to avoid nesting CompletableFuture when combining 2 independent ones with a BiFunction that returns a third one. Currently, using thenCombine() does not cut it: I’m basically trying to find a way that looks like haskell if there was a CompletableFuture monad: I read somewhere that join() is the flatMap of Completable future, so I think I could use

I have an enum, but i dont know how can I use correctly?

I searched so long for what enums are useful. In my Opinion there are Variables with many keywords. So have to programming a program what Is used to manage a bank. My Enum has 2 Variables EINZAHLUNG(Deposit) and AUSZAHLUNG(Payout). So I have an class Menue which is provide to call the Methods. The menue would be chosen by an UserInput.

Stream Way to get index of first element matching boolean

I have a List<Users>. I want to get the index of the (first) user in the stream with a particular username. I don’t want to actually require the User to be .equals() to some described User, just to have the same username. I can think of ugly ways to do this (iterate and count), but it feels like there should

Initialize list if list is null with lombok getter?

I am currently replacing all my standard POJO’s to use Lombok for all the boilerplate code. I find myself keeping getters for lists because I want to return an empty list if the list has not been initialized. That is, I don’t want the getter to return null. If there some lombok magic that I’m not aware of that can

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