Questions tagged [supplier]
70 questions
0
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1 answer
Still getting "stream has already been operated upon or closed" error
I'm reading lines from a txt file trying to get two lines at once (current and next). I use Supplier, but still get the error.
Stream lines = Files.lines(Paths.get(fileName));
Supplier> streamSupplier = () ->…

Николай Беляков
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3 answers
Java Supplier<> get origins information
I Use the Supplier in my code to call restTemplate and make the custom Message when have exception..
But, im my message, i need get information by my requestCall, But when i cast the request the java thow error
...
My code:
public void execute()…

Fernando Schotten
- 21
- 3
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1 answer
Correct use of Java 8 supplier consumer
I'm still strugling with Suppliers and Consumers for Java 8, I have this:
final Set roles = new HashSet<>();
user.getRoleGroups().forEach(rg -> rg.getRoles().forEach(r -> roles.add(r.getName())));
To get a Set from role names that are…

Leandro Diniz
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How to find the percentage of a single product of a supplier's total revenue?
There are multiple suppliers and each has sold multiple products. How would I find the percentage of the revenue of one of their products against that supplier's total sales in SQL?
Here is an example of data I have to work…

dizmaldizmay
- 3
- 1
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Make java supplier return a value using side effect
I have a java suppler that returns a Student pojo like so:
@Bean
public Supplier studentSupplier() {
return () -> new Student();
}
Now I want to make this supplier returns a Student pojo after an entry is created using…

java_doctor_101
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Supplier INT returning the value that I enter + Predicate that tells if the number I enter is prime or not
I have the next task:
Write a Supplier of type that returns a number read by screen with a block lambda expression
Write a Predicate that tells us if the entered number is a prime with a block expression that has a for loop. Apply it to the…

Clavillo
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System.out.println doesn't work on a supplied Stream?
I'm still new to Java, and especially new to Suppliers, but I can't figure out why I can't get any output from the following code:
final BufferedReader brLines = new BufferedReader(new InputStreamReader(csvFile));
final…

kn0wmad1c
- 110
- 10
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0 answers
Cast Supplier to Supplier java
I have an Interface IParent, an abstract class implementing it AbstractChild and a class extending the abstract class ConcreteChild. One other class Foo requires an instance of a Supplier.
My problem is that I have an instance of a…

Kostas Thanasis
- 368
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2 answers
How can I read a character from an InputStream and return it in a Supplier (Java)
So I have a method I need to implement. It gets an InputStream and returns a Supplier like this:
public Supplier buildPipe(InputStream input)
Now I want to read a character from the InputStream (probably with the read()-method) and return…

Sir0
- 3
- 3
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3 answers
Supplier interface for constructor reference
the following code
Supplier newString = String::new;
System.out.println(newString.get());
// prints an empty string (nothing) to the console and then a newline character
and for the definition of Supplier get method
T get()
the get method…

user1169587
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1 answer
How can we create an instance for Supplier as it is an Interface?
I am trying to understand Supplier interface. I understand that it can return an object if we invoke its get() method. However, in the following example:
public class SupplierExample {
public static void main(String[] args) {
…

Sukh
- 424
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3 answers
Java - How to read a file twice using buffer reader or use stream twice
How to read file twice eihher using buffer reader or using stream twice ???
That I need manipulate large amounts of data in the code, so the performance needs to be considered.
Sample code 1 below, gives exception "stream closed" -
Url url =…
user10386436
0
votes
3 answers
JAVA-STREAM : re-use double a DoubleStream
I need a trick to solve this problem i'm using Java 1.8 And I retrieved a an object from a method that returns a DoubleStream object. So, the problem is I could not reuse the stream after it has been consumed.
Here is the first version of the code…

Rodik
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The constructed object of type xxx is incompatible with the descriptor's return type: T
I am trying to build a Collector class that will summarize my results into a TreeMap. I am having trouble using a generic type for the accumulator/results. The problem occurs in the definition of my supplier method.
My class currently looks like…

Ben
- 31
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3 answers
How to define a BiFunction using a Supplier as Fallback to produce some objects?
What's wrong with this code? I need to create a factory method which is dependend on a BiFunction to fulfil it's job .
The compiler told me:
The method apply(Class, Supplier)
in the type BiFunction,Supplier,T>
is not applicable…

motte
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