How to make pagination at List in java

ListUtils.java

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.List;

/**
 * Reference: https://stackoverflow.com/questions/19688235/how-to-implement-pagination-on-a-list
 * @author elvis
 * @version $Revision: $<br/>
 *          $Id: $
 * @since 6/21/17 7:28 PM
 */
public class ListUtils {

    public static <T> List<T> getPage(List<T> sourceList, int page, int pageSize) {

        if(pageSize <= 0 || page <= 0) {
            throw new IllegalArgumentException("invalid page size: " + pageSize);
        }

        int fromIndex = (page - 1) * pageSize;
        if(sourceList == null || sourceList.size() < fromIndex){
            return Collections.emptyList();
        }

        // toIndex exclusive
        return sourceList.subList(fromIndex, Math.min(fromIndex + pageSize, sourceList.size()));
    }

    public static <T> void doPaginated(Collection<T> fullList, Integer pageSize, Page<T> pageInterface) {

        final List<T> list = new ArrayList<T>(fullList);
        if (pageSize == null || pageSize <= 0 || pageSize > list.size()){
            pageSize = list.size();
        }

        final int numPages = (int) Math.ceil((double)list.size() / (double)pageSize);
        for (int pageNum = 0; pageNum < numPages;){
            final List<T> page = list.subList(pageNum * pageSize, Math.min(++pageNum * pageSize, list.size()));
            pageInterface.run(page);
        }
    }

    public interface Page<T> {
        void run(List<T> item);
    }
}

ListUtilsTest.java

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

import org.junit.Assert;
import org.junit.Test;

/**
 * @author elvis
 * @version $Revision: $<br/>
 *          $Id: $
 * @since 6/21/17 7:35 PM
 */
public class ListUtilsTest {

    @Test
    public void doPaginated_InTwoPages() throws Exception {
        
        final List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
        final int pageSize = 4;
        final List<List<Integer>> results = new ArrayList<>();

        ListUtils.doPaginated(numbers, pageSize, x -> {
            results.add(x);
        });

        Assert.assertEquals("[[1, 2, 3, 4], [5, 6]]", results.toString());
    }

    @Test
    public void doPaginated_PerfectDivision() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
        final int pageSize = 2;
        final List<List<Integer>> results = new ArrayList<>();

        ListUtils.doPaginated(numbers, pageSize, x -> {
            results.add(x);
        });

        Assert.assertEquals("[[1, 2], [3, 4], [5, 6]]", results.toString());
    }

    @Test
    public void doPaginated_EmptyList() throws Exception {

        final List<Integer> numbers = Arrays.asList();
        final int pageSize = 2;
        final List<List<Integer>> results = new ArrayList<>();

        ListUtils.doPaginated(numbers, pageSize, x -> {
            results.add(x);
        });

        Assert.assertEquals("[]", results.toString());
    }

    @Test
    public void doPaginated_PageSizeGreaterThanList() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2);
        final int pageSize = 3;
        final List<List<Integer>> results = new ArrayList<>();

        ListUtils.doPaginated(numbers, pageSize, x -> {
            results.add(x);
        });

        Assert.assertEquals("[[1, 2]]", results.toString());
    }

    @Test
    public void doPaginated_PageSizeEqualToList() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2);
        final int pageSize = 2;
        final List<List<Integer>> results = new ArrayList<>();

        ListUtils.doPaginated(numbers, pageSize, x -> {
            results.add(x);
        });

        Assert.assertEquals("[[1, 2]]", results.toString());
    }

    @Test
    public void testGetPage_PaginationInTwoPages() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
        final int pageSize = 4;
        int page = 1;

        Assert.assertEquals("[1, 2, 3, 4]", ListUtils.getPage(numbers, page++, pageSize).toString());
        Assert.assertEquals("[5, 6]", ListUtils.getPage(numbers, page++, pageSize).toString());
        Assert.assertEquals("[]", ListUtils.getPage(numbers, page++, pageSize).toString());

    }

    @Test
    public void testGetPage_PageSizeGreaterThanList() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
        final int pageSize = 10;
        int page = 1;

        Assert.assertEquals("[1, 2, 3, 4, 5, 6]", ListUtils.getPage(numbers, page++, pageSize).toString());
        Assert.assertEquals("[]", ListUtils.getPage(numbers, page++, pageSize).toString());

    }

    @Test
    public void testGetPage_PageSizeEqualToList() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
        final int pageSize = 6;
        int page = 1;

        Assert.assertEquals("[1, 2, 3, 4, 5, 6]", ListUtils.getPage(numbers, page++, pageSize).toString());
        Assert.assertEquals("[]", ListUtils.getPage(numbers, page++, pageSize).toString());

    }

    @Test
    public void testGetPage_PerfectDivision() throws Exception {

        final List<Integer> numbers = Arrays.asList(1, 2, 3, 4, 5, 6);
        final int pageSize = 2;
        int page = 1;

        Assert.assertEquals("[1, 2]", ListUtils.getPage(numbers, page++, pageSize).toString());
        Assert.assertEquals("[3, 4]", ListUtils.getPage(numbers, page++, pageSize).toString());
        Assert.assertEquals("[5, 6]", ListUtils.getPage(numbers, page++, pageSize).toString());

    }

    @Test
    public void testGetPage_EmptyList() throws Exception {

        final List<Integer> numbers = Arrays.asList();
        final int pageSize = 4;
        int page = 1;

        Assert.assertEquals("[]", ListUtils.getPage(numbers, page, pageSize).toString());
        Assert.assertEquals("[]", ListUtils.getPage(numbers, ++page, pageSize).toString());

    }

}