Custom HashMap using Java

public class Entry<K, V> {

    K key;
    V value;
    Entry<K, V> next;

    public Entry(K key, V value, Entry<K, V> next) {
        this.key = key;
        this.value = value;
        this.next = next;
    }

    /**Usually in HashMap Entry Looks like this
     *
     * ------------------------------------------
     * |  Key  |  Value  | Next Entry reference |
     * ------------------------------------------
     * **/


    public K getKey() {
        return key;
    }

    public void setKey(K key) {
        this.key = key;
    }

    public V getValue() {
        return value;
    }

    public void setValue(V value) {
        this.value = value;
    }

    public Entry<K, V> getNext() {
        return next;
    }

    public void setNext(Entry<K, V> next) {
        this.next = next;
    }
}





/**HashMap**/

public class CustomHashMap<K, V> {

    private Entry<K, V>[] buckets;
    private static final int capacity = 16;

    public CustomHashMap(Entry<K, V>[] buckets) {
        this.buckets = new Entry[capacity];
    }

    public void put(K key, V value) {

        //check if key is null because it does not allow to store null.
        if (key == null) {
            return;
        }
        //get the bucket count for key using hash function
        int bucketCount = hash(key);
        //create new Entry
        Entry<K, V> newEntry = new Entry<K, V>(key, value, null);

        //check in same bucket whether already we have entry or not
        //if no entry present then directly add this entry
        if (buckets[bucketCount] == null) {
            buckets[bucketCount] = newEntry;
        } else {

            Entry<K, V> previous = null;
            Entry<K, V> current = buckets[bucketCount];

            while (current != null) {
                //if key is same then replace the value
                if (current.getKey().equals(key)) {
                    current.setValue(value);
                    break;
                }
                previous = current;
                current = current.getNext();
            }
            if (previous != null)
                previous.setNext(newEntry);
        }

    }

    public V get(K key) {
        int hash = hash(key);
        Entry<K, V> entry = buckets[hash];
        if (entry.getKey().equals(key)) {
            return entry.getValue();
        } else {
            return null;
        }
    }

    private int hash(K key) {
        return key.hashCode() % capacity;
    }
}