You can view the sample code associated with this post on GitHub.

Taking a stream of POJOs and transforming it into a map is one of the more common uses of Streams. There are a few built in ways to get what you want. The simplest way to map one field to another in a POJO is by using the .toMap(..) method.

You can view the sample code associated with this post on GitHub.

Calling collect(..) on a stream terminates a stream into a collection. We’ve already seen that calling collect(Collectors.toList()) moves your stream into a List, but you can also collect into a set. If we take our familiar collection of names in a String collection:

You can view the sample code associated with this post on GitHub.

While Optionals are often used in conjunction with the Java Stream API, you can also create your own. Now, why would you want to do that? Simply put, null pointer exceptions are not a fun time, and embracing optional types will greatly simplify code development, and prevent premature graying hair.

You can find the sample code associated with this post on GitHub.

If Java programmers had a generic Facebook page, they would collectively have an “it’s complicated” relationship with the null value.

The sample code associated with this post can be found on GitHub.

Sometimes, we will have two different streams of data that we want to aggregate into one stream to analyze. In that case, we can use the Stream.concat(..) method. Here, if we take our list of names from before:

You can find the sample code for this post on GitHub.

From the knowledge gained via creating custom Java Stream objects, we can start to have a little bit of fun with this. The fibonacci number sequence starts with [0, 1], and adds each of the previous two elements to create the next element in the sequence. This looks like [0, 1, 1, 2, 3, 5, 8, 13, 21…], and goes on “forever.” We can thus create a template that computes all Fibonacci numbers by implementing a Supplier. like so:

You can find the sample code from this post on GitHub.

There are a few built in ways to create your own custom streams. While many collections offer a direct .stream() method, you can also use Stream.of(..) to just make one in place:

The sample code provided with this series on the Java Stream API can be retrieved on GitHub.

I’ve been working on a small wpf project on GitHub that let’s you view SEC filings on your desktop in an intuitive way. Since EDGAR kind of sucks for a casual user, this is much more appealing.

The old recommended way of getting packages like bootstrap and jquery easily into a project was to use bower. That was convenient to add packages for projects where you were planning on providing mostly server-side functionality, and could use bootstrap to handle page styling, for example.

Modern day website owners prefer not to leave their email address open and exploitable on the internet. Enter the Contact page, which will usually have some basic fields for the visitor of the site to fill out like Name, Email Address, Phone, and Message to send to someone who can help them out.