Program to Convert a Set to Stream in Java Using Generics

A Set in Java is a collection of unique elements, whereas a Stream effectively performs functional tasks such as filtering, mapping, and decreasing data. Converting a Set to a Stream enables straightforward processing of its elements using the Stream API, which was introduced in Java 8. We may use generics to design a reusable method that works with any type of Set while maintaining type safety and flexibility.

What is Set?

Java Set is part of the java.util package and extends the java.util.Collection interface. It allows the use of repeated elements and can only handle a null element.

What is Stream?

A stream is a collection of objects that support various methods and can be pipelined to obtain the desired result.

There are two methods to convert a set to stream

1. Using Collection.Stream() method
2. Using Predicate

Method 1: Using Collection.stream() Method

In this approach, the Set is converted directly to a Stream using Collection.stream().

Algorithm

Step 1: Create a method that takes a Set as input, where T is any data type.

Step 2: Ensure the method returns a Stream for flexible data processing.

Step 3: Use the.stream() method in Java 8, to transform a Set into a Stream.

Step 4: Declare and initialize a Set with any data type (e.g., integer, string).

Step 5: Use the generic method to get a Stream representation of the Set.

Step 6: Convert the stream to an array or use any stream operations (such as filtering and mapping).

Step 7: Print the results to ensure that the conversion was successful.

Output:

 The Set of Integer are: [1, 3, 4, 5, 9, 10] The Stream of Integer are: [1, 3, 4, 5, 9, 10] 

Method 2: Using Predicate

This method uses the filter(Predicate) method to return a stream of elements that satisfy the provided predicate condition. The Functional Interface Predicate is specified in the java.util.Function package so that it can be used as the assignment target for a lambda expression or method reference. It increases the manageability of code and aids in unit testing it individually.

Algorithm

Step 1: Create and initialize a Set that includes multiple string members.

Step 2: Print the Set elements before applying any filters.

Step 3: Define a Predicate that determines whether a string begins with the letter 'J'.

Step 4: Create a function that accepts a Set and a Predicate as input.

Step 4: Call the conversion function and pass the Set and Predicate as arguments. Store the filtered Stream that is resulted.

Step 5: Convert the set to a stream.

Step 6: Use the Predicate to filter elements from the stream.

Step 7: Returns the filtered Stream.

Step 8: Convert the Stream to an array to make it easier to display.

Step 9: Print the filtered elements that satisfy the given condition.

Output:

 A set that contains a collection of strings are: [Jasmin, Programming, Website, JavaTpoint, follow, Good] The stream from the set that starting with the 'J' are: [Jasmin, JavaTpoint]