Creating Threads
Understand how to create threads in Java by implementing Runnable or extending Thread. Learn to start threads properly, use lambdas for concise task definitions, and synchronize execution with join to build responsive, concurrent applications.
We now understand that threads are independent paths of execution that allow our programs to do multiple things at once. But knowing the theory doesn’t run code. To build responsive applications, we need to know exactly how to create these execution paths and control their lifecycles.
In this lesson, we will move from concept to implementation. We will write code to define tasks, hand them off to the JVM for execution, and ensure they complete exactly when we need them to.
Implementing the Runnable interface
The primary way to define a task in Java is by implementing the Runnable interface. By using Runnable, we separate the task (the logic) from the runner (the thread). This is considered best practice because it keeps the business logic separate from the threading infrastructure.
Java only allows a class to extend one superclass. If we were to define a thread by extending the Thread class directly, we would lose the ability to extend any other class. Implementing Runnable avoids this limitation, leaving our class inheritance open for other uses.
We define the work in a ...