Java Convert Array to ArrayList

In Java, we can use new ArrayList<>(Arrays.asList(array)) to convert an Array into an ArrayList

package com.mkyong;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class ArrayExample1 {
    public static void main(String[] args) {
        String[] str = {"A", "B", "C"};
        List<String> list = new ArrayList<>(Arrays.asList(str));
        list.add("D");
        list.forEach(x -> System.out.println(x));

Output

The Arrays.asList returns a fixed or unmodifiable list, if we modify the list, UnsupportedOperationException will be thrown.

	List<String> list = Arrays.asList(str); 				 // unmodifiable list
	list.add("D"); 		// java.lang.UnsupportedOperationException
	List<String> list2 = new ArrayList<>(Arrays.asList(str)); // modifiable list
	list2.add("D"); 	// ok

1. Java 8 Stream

package com.mkyong;
import java.util.ArrayList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.Stream;
public class ArrayExample2 {
    public static void main(String[] args) {
        String[] str = {"A", "B", "C"};
        ArrayList<String> list1 = Stream.of(str).collect(Collectors.toCollection(ArrayList::new));
        list1.add("D");
        list1.forEach(x -> System.out.println(x));
        List<String> list2 = Stream.of(str).collect(Collectors.toList());
        list2.add("D");
        list2.forEach(x -> System.out.println(x));

Output

2. Java 9 – List.of()

P.S List.of returns fixed or unmodifiable list

package com.mkyong;
import java.util.ArrayList;
import java.util.List;
public class ArrayExample3 {
    public static void main(String[] args) {
        String[] str = {"A", "B", "C"};
        // Java 9
        List<String> list = new ArrayList<>(List.of("A", "B", "C"));
        list.add("D");
        list.forEach(x -> System.out.println(x));

Output