Hello Friends,

In this tutorial, we will learn, various ways in which we can convert an array to a List.

package com.blogspot.javasolutionsguide;

import com.google.common.collect.Lists;
import org.apache.commons.collections4.CollectionUtils;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.LinkedList;
import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;
import java.util.stream.Stream;

public class ArrayToList {

 public static void main(String[] args) {

 //Before Java 8
 System.out.println("Before JAVA 8........................................");

 // 1.
 String[] names = new String[] {"Gaurav", "Sachin", "Yuvraj"};
 List<String> nameList = Arrays.asList(names);
 System.out.println("using Arrays.asList: " + nameList);

 //2
 List<Integer> list = Arrays.asList(1, 2, 3);
 System.out.println("Inline primitive array to Integer List using Arrays.asList(): "
 + list);

 //Java 8
 System.out.println("JAVA 8 ................................................");
 // 3. primitive array
 int intArray[] = {1, 2, 3};
 List<Integer> integerList1 = Arrays.stream(intArray).boxed()
 .collect(Collectors.toList());
 System.out.println("Primitive int array to Integer List using Array.stream(): "
 + integerList1);

 // 4. primitive array with IntStream
 List<Integer> integerList2 = IntStream.of(intArray).boxed()
 .collect(Collectors.toList());
 System.out.println("Primitive int array to Integer List using IntStream.of(): "
 + integerList2);

 // 5. Object type array to Integer List
 Integer integerArray[] = {1, 2, 3};
 List<Integer> integerList3 = Arrays.stream(integerArray)
 .collect(Collectors.toList());
 System.out.println("Object type array to Integer List using Arrays.stream: "
 + integerList3);

 // 6. Integer Array to ArrayList
 ArrayList<Integer> arrayList = Arrays.stream(integerArray)
 .collect(Collectors.toCollection(ArrayList::new));
 System.out.println("Integer type array to Integer ArrayList using Arrays.stream: "
 + arrayList);

 // 7. Integer Array to LinkedList
 LinkedList<Integer> linkedList = Stream.of(integerArray)
 .collect(Collectors.toCollection(LinkedList::new));
 System.out.println("Integer type array to Integer LinkedList using Arrays.stream: "
 + linkedList);

 // 8. Integer Array to Immutable List
 List<Integer> immutableList = Collections.unmodifiableList(Arrays.asList(integerArray));
 System.out.println("Integer type array to Immutable List using Arrays.stream: "
 + immutableList);

 //9. JAVA 9
 System.out.println("JAVA 9.........................................................");
 String[] playerNames = {"Sachin", "Dhoni", "Yuvraj"};
 List<String> players = List.of(playerNames);
 System.out.println("Array to List using Java 9 List.of() :" + players);

 //10. JAVA 10
 System.out.println("JAVA 10.........................................................");
 List<Integer> integerList = List.copyOf(Arrays.asList(integerArray));
 System.out.println("Array to List using Java 10 List.copyOf() :" + integerList);

 //11. Apache Commons
 System.out.println("Apache Commons...................................................");
 List<Integer> targetList = new ArrayList<>(6);
 CollectionUtils.addAll(targetList, integerArray);
 System.out.println("Array to List using Apache Common CollectionUtils.addAll() :"
 + integerList);

 //12 Google Guava
 System.out.println("Google Guava......................................................");
 Integer[] sourceArray = {1, 2, 3};
 List<Integer> targetList1 = Lists.newArrayList(sourceArray);
 System.out.println("Array to List using Google Guava Lists.newArrayList:"
 + integerList);
 }
}

External Dependency Used :

<dependency>
 <groupId>org.apache.commons</groupId>
 <artifactId>commons-collections4</artifactId
 <version>4.4</version>
 </dependency>
 <dependency>
 <groupId>org.apache.commons</groupId>
 <artifactId>commons-lang3</artifactId>
 <version>3.10</version>
 </dependency>
 <dependency>
 <groupId>com.google.guava</groupId>
 <artifactId>guava</artifactId>
 <version>16.0.1</version>
 </dependency>

All the code for this tutorial can be found in GitHub. So in this tutorial we learnt various ways in which we can convert array to List in java.That is all for this tutorial.Please subscribe the blog for more such tutorial.