599 questions
0
votes
2
answers
107
views
Interface overriding extending functional interface method as default and having an abstract method works abruptly
@FunctionalInterface
interface StringConsumer extends Consumer<String> {
@Override
public default void accept(String s) {
System.out.println(s.toUpperCase());
}
void ...
- 11
-3
votes
1
answer
186
views
Mocked method inside lambda expression is not working
I am using the mockito but connection.prepareStatement is not getting matched and I am getting null as PreparedStatement. I have checked connection is getting mocked properly
void myMethod(){
...
- 335
0
votes
1
answer
281
views
Instance of object without implementing an interface [duplicate]
I have a code sample that defines a Worker interface and an Employee class that does not implement that interface. In my main method, I declare a Worker called w and instantiate it as an Employee.
...
- 1,948
0
votes
2
answers
198
views
Can not create Function array in Java 8
I have a class called SFunction which extends from Function in JDK 8
@FunctionalInterface
public interface SFunction<T, R> extends Function<T, R>, Serializable {
}
Now I have several ...
- 13.5k
0
votes
1
answer
198
views
Struggling to inject my mocked Runnable into my service call
For context, I'm using Resilience4j to handle exceptions and invoke retries. This is done through RetryService.
In this function, callRunnableWithRetry() there are two params. 1st is a string, the 2nd ...
- 464
0
votes
1
answer
89
views
Java FunctionalInterface with variable number of arguments
I want to write a very lightweight library method, that will take any number of java lambda functions, execute them with auto-commit turned off. Should an error occur it would rollback. So the lambda ...
- 188
0
votes
2
answers
1k
views
Predicates and functions
public static void main(String[] args) {
List<String> strings = Arrays.asList("a", "b", "c", "d");
strings.stream()
.filter(s -> ...
- 3,923
0
votes
1
answer
51
views
@FunctionalProtocols for Swift?
My Problem
I'm looking for a while for an equivalent of Javas @FunctionalInterface in Swift.
Swift is titled as Protocol-Oriented Programming Language and known for his Syntactic Sugar. So I hope ...
- 23
0
votes
0
answers
50
views
BiFunction error during method reference with multiple arguments
I'm working on a code to put objects to S3. I've a wrapper method that logs the call details and request/ response information. While i try to use the wrapper for s3.putObject/ s3.headObject calls, ...
- 39
1
vote
2
answers
94
views
Unable to pass Consumer<> instance
I have a class for walking a directory tree and performing an action on each file/directory. It looks like this:
class DirWalker {
public static void walkDirs(Path startingPath, Consumer<Path>...
- 2,374
1
vote
3
answers
156
views
Java BiFunction to manipulate data over an iteration
I'm writing a Java code that looks like this, and I have the feel it could be improved with some functional programming stuff :)
int rank = 1;
for (int i = 0; i < activities.size(); i++) {
if (...
-1
votes
1
answer
72
views
Storing methods in fields in java (cleanly)
My situation is designing my game with Javas OOP as clean as I can I need to store static methods of the another class into a field of current without using try{}catch{}. Being more specific I need to ...
- 95
1
vote
0
answers
34
views
Method compose, in interface Function
public Function<V, U> compose(Function<? super V, ? extends T> before)
Can someone explain the way "? super T" works, why we need "super" in this interface to make ...
- 11
-1
votes
1
answer
73
views
using functional interfaces in java [closed]
I have ProductSettings and ProductType. Product settings determine whether product types are enabled or not.
ProductSettings productSettings = new ProductSettings()
....
-1
votes
1
answer
110
views
How to make a static version of a Map holding getters/setters of an object?
I have a map I build when called on object that provides caller with variable names as key and getter/setter pair as values. This works as expected. My issue is that I build it every time I call for ...
- 31