Java: How to get the name of the current thread

When you’re working with multi-threaded programming in Java — such as when working with Thread, Runnable, SwingUtilities.invokeLater, Akka, futures, or Observable in RxJava — you may need to get the name of the current thread as a way to debug your code. Here’s how you get the name of the current thread in Java:

Android: How to send a message from a Thread to a Handler alvin August 30, 2017 - 10:29am

As a quick example of how to use a Thread with a basic Handler in an Android application, the following code creates a view where the text in the TextView is updated to show the current date and time when the Button is tapped.

Java source code

First, here’s the Java source code for a file class named ThreadHandlerActivity:

The Java 8 lambda Thread and Runnable syntax and examples

As a quick note, here are some examples of the Java 8 lambda Thread and Runnable syntax. As a little bonus I also show the Java lambda syntax in other situations, such as with an ActionListener, and several “handler” examples, including when a lambda has multiple parameters.

Android Room, database I/O, and Java 8 threads

I just started working with the Android Room database persistence library, and since you’re not supposed to run things like database queries on the main thread (the UI thread), I was looking at other ways to run them.

In general, you probably won’t want to run database queries using a Thread, but just to see how Room works, I wrote this Java Thread code, and confirmed that it works as expected:

An example of Android StrictMode output (with improper database access)

I was just working with an example of how to use Android’s new Room Persistence Library, and the example I was working with ran some of its code on the main Android thread, also known as its “UI thread.” I knew this was bad, but I wanted to start with someone’s example, and then figure out a good way to get the Room method calls to run on a background thread, such as using an AsyncTask. (The Android docs don’t specify a “best practice” for this atm.)