One of the major new language features in Java 8 is the lambda function. In fact, it is one of the biggest changes since the Java 1 release. Take a look at this introduction to Java 8's lambda function.

An article about how to override the default security-related information associated with a JAX-RS request using a custom SecurityContext.

There are a lot of ways to implement Access Controls, and some are slightly complicated. Have you considered using REST?

Using Maven to effectively test software when test classes are not already packaged by Maven.

Testing that goes beyond just unit testing and integration testing. Why we should be doing full system testing.

[Ivan Zerin provides a primer on mocking methods that contain generic return types.] There are several cases where construction when().thenReturn is not suitable during Unit tests. One of then generic return type. I have faced such issue, let's take a look. There is a method in interface declaration: public interface FooInterface { public Iterable getList(); ... } Implementation looks like this: public class Foo implements FooInterface { public List getList() { ... } ... } At first mocking of such method should not be something unusual: public class UnitTest { @Mock private FooInterface mockFoo; @Test public void someUnitTest() { ... List testList = generateTestList(); when(mockFoo.getList()) .thenReturn(testList); } } But this code won't compile with error: Cannot resolve method 'thenReturn(List). Seems to be some mistake, cause returned type are correct from the interface point of view. This error happening cause compiler can not gurantee that returned type of method getList() will be List. Actually return type of method getList() in this case is Iterable and this means "Return some Iterable object with any objects that extends SomeClass". Let's rename this type as 'X'. So when(mockFoo.getList()) will create object OngoingStubbing> and it has method thenReturn(Iterable). Compiler can not tell what type X before runtime and cannot perform safe cast from List to Iterable (we perfrom actuall call of method thenReturn(List)). Sounds a little tricky but let's assume that SomeClass is standard Java class Number. Then classes Integer and Double are both fulfill the criteria of List. Let's say that as return type of mock we will use List, in this case, compiler should be ready that actual work with code during runtime will be performed with List too, but it is clearly that cast from Double to Integer will be incorrect (try to cast double value 12.6 to int). You could argue that in the case of mockito compiler won't need to bother about the casting of returned type because call of original method would not produce anything, but it is known by mockito. From compiler point of view, it is only Java code, that should be checked for safety and correctness before compiling. Ok, so how we should deal with such cases in mockito? Use doReturn() method: doReturn(testList).when(mockFoo).getList(); Such expression is not type safe, so it were designed for exceprional cases, so use it only when you cannot use standart when().thenReturn(), which is the type-safe, elegant and more readable syntax.

Should constructors throw exceptions? What can the 1815 Congress of Vienna teach us about good Java design?

Spring Security is an extensible framework for authentication, including support for OAuth 2 and JSON Web Token, two popular choices.

A practical introduction to the new and improved Date & Time API in Java 8. If you've not had chance to review or use it yet then start here!

When you are new to both Docker and IntelliJ how do you deploy your Java EE applications? Steve Favez shows you how.

How a new feature in Spring lets you manage sessions without relying on external repositories.

Are you a Java Champion? Now you can get IntelliJ IDEA Ultimate as yet another reward.

Working with off-heap storage can make a big difference when working with large data sets. But how do you know how much memory you have at your disposal? Read this article and find out!

Learn the basics on how to write robust immutable Java objects and reap the benefits of immutable objects in your code.

Is Java the new Cobol? Probably, but Cobol is still running. Java will be in enterprises for at least 20 more years.

This tutorial will teach you that you don't need to pilot an A-Wing to shut down these ExecutorServices.

Monitoring, diagnosing, and troubleshooting are key activities in any enterprise application lifecycle, and logging is the core part of these activities. Meet Logback, a logging framework from the creator of Log4J.

An introduction to immutable classes in Java, such as a String class.

A great way to keep looping code out of your main logic in Java 8 apps.

See how detecting Java race conditions is actually rather easy. In Part I of this two-part article, you will see how to detect lost updates, the first type of Java race conditions.