In this tutorial, we will see “How to convert a List to a Stream in Java 8?” And, also we will learn how to filter the stream using Predicate.
Convert a List to a Stream & filter the stream in Java 8 with example...!!! Share on X
Example 1. Convert a List to a Stream
To convert list to a stream, we are going to use List.stream() which returns a sequential Stream with the collection as its source.
import java.util.Arrays;
import java.util.List;
import java.util.stream.Stream;
class Convert_List_To_Stream_Java8 {
public static void main(String args[]) {
// Create a list of string
List <String> listObj = Arrays.asList("Techndeck", "Technology Blog", "For Programmers & Entrepreneurs");
// Print the List
System.out.println("List: \n" + listObj);
// Convert List to stream
Stream <String> stream = listObj.stream();
// Print the Stream
System.out.println("\nStream: \n" + Arrays.toString(stream.toArray()));
}
}
Output:
List: [Techndeck, Technology Blog, For Programmers & Entrepreneurs] Stream: [Techndeck, Technology Blog, For Programmers & Entrepreneurs]
Example 2. Filter a Stream using Predicate
Predicate is a function interface part of the java.util.function package. It’s main purpose is to be used as a assignment target for a lambda expression. To filter the stream, we are going to use filter(predicate expression) to build a stream of elements which matches the predicate expression.
import java.util.Arrays;
import java.util.List;
import java.util.function.Predicate;
class Filter_Stream_Using_Predicate_Java8 {
public static void main(String args[]) {
// Create a list of string
List <String> listObj = Arrays.asList("Techndeck", "Technology Blog", "For Programmers & Entrepreneurs");
// Print the List
System.out.println("List: \n" + listObj);
// Create the predicate which build with items starting with character 'T'
Predicate <String> predicateObj = s -> s.startsWith("T");
System.out.println("\nStream from List whose items starting with 'T': ");
// Convert List to stream with predicate filter and print it
listObj.stream()
.filter(predicateObj)
.forEach(System.out::println);
}
}
Output:
List: [Techndeck, Technology Blog, For Programmers & Entrepreneurs] Stream from List whose items starting with 'T': Techndeck Technology Blog
Convert a List to a Stream & filter the stream in Java 8 with example...!!! Share on X
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