[Q#1073919][A#1073933] How to convert int[] into List<Integer> in Java?

https://stackoverflow.com/q/1073919

How do I convert int[] into List<Integer> in Java? Of course, I'm interested in any other answer than doing it in a loop, item by item. But if there's no other answer, I'll pick that one as the best to show the fact that this functionality is not part of Java.

Answer

https://stackoverflow.com/a/1073933

There is no shortcut for converting from int[] to List<Integer> as Arrays.asList does not deal with boxing and will just create a List<int[]> which is not what you want. You have to make a utility method.

APIzation

int[] ints = {1, 2, 3};
List<Integer> intList = new ArrayList<Integer>();
for (int i : ints)
{
    intList.add(i);
}

package com.stackoverflow.api;

import java.util.ArrayList;
import java.util.List;

public class Human1073933 {

  public static List<Integer> toList(int[] ints) {
    List<Integer> intList = new ArrayList<>();
    for (int i : ints) {
      intList.add(i);
    }
    return intList;
  }
}

package com.stackoverflow.api;

import java.util.ArrayList;
import java.util.List;

/**
 * How to convert int[] into List<Integer> in Java?
 *
 * @author APIzator
 * @see <a href="https://stackoverflow.com/a/1073933">https://stackoverflow.com/a/1073933</a>
 */
public class APIzator1073933 {

  public static void convertInt(int[] ints) throws Exception {
    List<Integer> intList = new ArrayList<Integer>();
    for (int i : ints) {
      intList.add(i);
    }
  }
}