In this tutorial, we will see “How to convert a Stream to a List in Java 8?”
To achieve that, we are going to use Collectors.toList() operation available since Java 8.
Convert a Stream to a List in Java 8 with example...!!! Share on X
Example 1. With String
import java.util.List;
import java.util.function.Consumer;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Convert_Stream_To_List_Java_8_Example_1 {
public static void main(String[] args) {
System.out.println("Example 1: (Basic example with String) - Convert Stream to List\n");
Stream <String> persons = Stream.of("Tom", "John", "Peterson", "Tony", "Tim");
//Convert Stream to List
List <String> personList = persons.collect(Collectors.toList());
//Below mentioned all three forms will generate the same result. You can use any of those options.
//Printing list using Method Reference
System.out.println("Displaying list using Method Reference\n");
personList.forEach(System.out::println);
//Printing list using Lambda Expression
System.out.println("\nDisplaying list using Lambda Expression\n");
personList.forEach(person -> System.out.println(person));
//Printing list using Annonymous Inner Class
System.out.println("\nDisplaying list using Annonymous Inner Class");
personList.forEach(new Consumer <String> () {
@Override
public void accept(String person) {
System.out.println(person);
}
});
}
}
Output:
Example 1: (Basic example with String) - Convert Stream to List Displaying list using Method Reference Tom John Peterson Tony Tim Displaying list using Lambda Expression Tom John Peterson Tony Tim Displaying list using Annonymous Inner Class Tom John Peterson Tony Tim
Example 2. With Filtered String
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Convert_Stream_To_List_Java_8_Example_2 {
public static void main(String[] args) {
System.out.println("Example 2: (with String but filtered) - Convert Stream to List\n");
Stream <String> persons = Stream.of("Tom", "John", "Peterson", "Tony", "Tim");
//Find person whose name starts with 'T' and then convert the Stream to List
List <String> personList = persons
.filter(person -> person.startsWith("T"))
.collect(Collectors.toList());
System.out.println("Displaying list using Method Reference\n");
personList.forEach(System.out::println);
}
}
Output:
Example 2: (with String but filtered) - Convert Stream to List Displaying list using Method Reference Tom Tony Tim
Example 3. With Integer
import java.util.List;
import java.util.function.Consumer;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Convert_Stream_To_List_Java_8_Example_3 {
public static void main(String[] args) {
System.out.println("Example 3: (Basic example with Integer) - Convert Stream to List\n");
Stream <Integer> numbers = Stream.of(10, 90, 43, 81, 25);
//Convert Stream to List
List <Integer> numberList = numbers.collect(Collectors.toList());
//Below mentioned all three forms will generate the same result. You can use any of those options.
//Printing list using Method Reference
System.out.println("Displaying list using Method Reference\n");
numberList.forEach(System.out::println);
//Printing list using Lambda Expression
System.out.println("\nDisplaying list using Lambda Expression\n");
numberList.forEach(person -> System.out.println(person));
//Printing list using Annonymous Inner Class
System.out.println("\nDisplaying list using Annonymous Inner Class");
numberList.forEach(new Consumer <Integer> () {
@Override
public void accept(Integer number) {
System.out.println(number);
}
});
}
}
Output:
Example 3: (Basic example with Integer) - Convert Stream to List Displaying list using Method Reference 10 90 43 81 25 Displaying list using Lambda Expression 10 90 43 81 25 Displaying list using Annonymous Inner Class 10 90 43 81 25
Example 4. With Filtered Integer
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class Convert_Stream_To_List_Java_8_Example_4 {
public static void main(String[] args) {
System.out.println("Example 4: (with Integer but filtered) - Convert Stream to List\n");
Stream <Integer> numbers = Stream.of(10, 90, 43, 81, 25);
//Find even numbers from the stream and then convert the Stream to List
List < Integer > numberList = numbers
.filter(number -> number % 2 == 0)
.collect(Collectors.toList());
System.out.println("Displaying list using Method Reference\n");
numberList.forEach(System.out::println);
}
}
Output:
Example 4: (with Integer but filtered) - Convert Stream to List Displaying list using Method Reference 10 90
Convert a Stream to a List in Java 8 with example...!!! Share on X
Do you like this Post? – then check my other helpful posts:
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