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Expanded Audience – Frontegg – Security (partner)
announcement - icon User management is very complex, when implemented properly. No surprise here.

Not having to roll all of that out manually, but instead integrating a mature, fully-fledged solution - yeah, that makes a lot of sense.
That's basically what Frontegg is - User Management for your application. It's focused on making your app scalable, secure and enjoyable for your users.
From signup to authentication, it supports simple scenarios all the way to complex and custom application logic.

Have a look:

>> Elegant User Management, Tailor-made for B2B SaaS

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1. Introduction

In this short tutorial, we'll illustrate the difference between Collections.emptyList() and a new list instance.

2. Immutability

The core difference between java.util.Collections.emptyList() and a new list e.g. new ArrayList<>() is immutability.

Collections.emptyList() returns a list (java.util.Collections.EmptyList) that can't be modified.

When creating a new list instance you can modify it depending on the implementation:

public void givenArrayList_whenAddingElement_addsNewElement() {	 	 
    List<String> mutableList = new ArrayList<>();	 	 
    assertEquals(mutableList.size(), 1);	 	 
    assertEquals(mutableList.get(0), "test");	 	 
@Test(expected = UnsupportedOperationException.class)	 	 
public void givenCollectionsEmptyList_whenAdding_throwsException() {	 	 
    List<String> immutableList = Collections.emptyList();	 	 

3. Object Creation

Collection.emptyList() creates a new empty list instance only once, as shown in source code:

public static final List EMPTY_LIST = new EmptyList<>();

public static final <T> List<T> emptyList() {
    return (List<T>) EMPTY_LIST;

4. Readability

When you want to explicitly create an empty list, then Collections.emptyList() expressed the original intention better e.g. new ArrayList<>().

5. Conclusion

In this to the point article, we've focused on the differences between the Collections.emptyList() and a new list instance.

As always full source code is available over on GitHub.

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