Getting max and min values from Array

My code works; I am just seeing if there's an optimized way to write these methods or even better perhaps combine them (since majority of their contents look similar).

public class IntegerUtils {

    public static int getMaxValue(int[] array) {
        int value = Integer.MIN_VALUE;

        if (array.length  value) {
                value = array[i];
            }
        }
        return value;
    }

    public static int getMinValue(int[] array) {
        int value = Integer.MAX_VALUE;

        if (array.length <= 0) {
            throw new IllegalArgumentException("Array is empty.");
        }

        for (int i=0; i < array.length; i++) {
            if (array[i] < value) {
                value = array[i];
            }
        }
        return value;
    }   
}

Here's my unit test (which works as well):

import org.junit.Test;

public class IntegerUtilsTest {

    int[] array = new int[] {1, 2, 3, 58, 47, 229, 40};

    @Test
    public void shouldBeMaxValue() {
        int maxValue = IntegerUtils.getMaxValue(array);
        assert(maxValue == 229);
    }

    @Test
    public void shouldBeMinValue() {
        int minValue = IntegerUtils.getMinValue(array);
        assert(minValue == 1);
    }

    @Test(expected = IllegalArgumentException.class)
    public void shouldBeIllegalArgumentException() {
        int[] emptyArray = new int[] {};
        int maxValue = IntegerUtils.getMaxValue(emptyArray);
        int minValue = IntegerUtils.getMinValue(emptyArray);
    }
}

Just seeking feedback regarding optimization and / or code elegance.

Real skill means knowing your libraries. Instead of 20 lines of handcrafted code, I'd rather go for:

int max = Arrays.stream(array).max().orElseThrow(() -> new IllegalArgumentException("Array is empty"));

... the same for min.

As a general advice: Java is a very mature language, and chances are good that every "simple everyday task" is already solved in the library. (Also note that most books on Java are from the pre-java-8 era and may be considered somewhat outdated today.)

StackExchange Code Review Q#162656, answer score: 8