How to convert List into a hashMap?

Question:

I'm capturing parameters from a request url using com.apache.http.NameValuePairwhich basically store those params in List<NameValuePair>. To do certain checks and verifications on those params, I need to convert that list into a HashMap<String, String>. Is there a way to do this conversion?

Answer:

You can use it for Java 8

public static <K, V, T extends V> Map<K, V> toMapBy(List<T> list,
        Function<? super T, ? extends K> mapper) {
    return list.stream().collect(Collectors.toMap(mapper, Function.identity()));
}

And here's how you would use it on a List:

Map<Long, Product> productsById = toMapBy(products, Product::getId);

Follow the link:

1. Converting ArrayList to HashMap
2. Generic static method constrains types too much
3. Java: How to convert List to Map

Original LInk: How to convert List<NameValuePair> into a hashMap<String, String>?