Master the ExecutionControl.StoppedException in JAVA: Uncover Its Nuances!

Are you a Java developer puzzled by the ExecutionControl.StoppedException? Have you ever come across this exception while running your Java code? If you answered yes to either of these questions, you’re in the right place.

The ExecutionControl.StoppedException in Java often causes undue stress in developers who encounter it. But no worries, this comprehensive guide will explore the depths of the ExecutionControl.StoppedException in Java and enlighten you on its nuances so you can wield it to your advantage.

What Is the ExecutionControl.StoppedException in Java?

Before we dive into the deep end, let’s cover some basics. ExecutionControl.StoppedException is a RuntimeException that, unlike checked exceptions, does not require to be declared in a method or constructor’s throws clause. This exception class belongs to the jdk.jshell package, introduced in JDK 9 as a part of the JShell API.

The ExecutionControl class in JShell API controls the execution of snippets, and one of its subclasses is StoppedException. This exception is thrown when snippet execution is stopped irrespective of its normal or exceptional completion.

public static class ExecutionControl.StoppedException
extends ExecutionControl.ExecutionControlException

When Does It Occur?

The ExecutionControl.StoppedException is thrown when the execution of a snippet is forcibly stopped, either because JShell closes or due to a user-initiated event. For example, if you’re running a loop in JShell and you manually stop it, it can throw this instance.

for(int i=0; i<100; i++){
  System.out.println(i);
}

If the above code in JShell is forcibly stopped, it may throw the ExecutionControl.StoppedException.

How to Handle ExecutionControl.StoppedException?

As this is a RuntimeException, we can either handle it using a try-catch or propagate it up the call stack. Here is how you can handle this exception:

try {
  // snippet execution
} catch (ExecutionControl.StoppedException e) {
  // Exception handling
}

Practical Usage of ExecutionControl.StoppedException

Although the practical usage of ExecutionControl.StoppedException is confined mainly to the JShell context, it’s an interesting addition to Java’s exception handling roster. Developers leveraging JShell in their applications can benefit from this exception by customizing their application’s behavior when snippet execution is interrupted.

For example, you might want to log an informative message to users when they stop the execution of a long-running task:

try {
    // code for executing long-running task
} catch (ExecutionControl.StoppedException e) {
    System.out.println("The task was stopped by user... IDLE mode activated");
    // switch to idle mode
}

Important Note

The jdk.jshell package, and by extension the ExecutionControl.StoppedException, is not intended for use in general-purpose applications. Not only is it somewhat niche, but its stability is not guaranteed—it might be removed or changed in the future Java versions.

Also, remember that all the exceptions in the ExecutionControl class are not meant to be caught, and even if caught they should never be ignored.

For more insights on this exception and the jshell package as a whole, you can go through the official Oracle documentation.

Wrapping Up

The ExecutionControl.StoppedException in Java might seem intimidating at first, but with the right understanding and usage, it can be another powerful tool in your Java toolkit. Embrace the nature of exceptions as your code’s communication method for errors and disruptions, and always remember, exceptions are your allies – handle them with care!

Stay in tune, as our next posts will be covering more about Java exception handling, offering you tips, tricks, and best practices. Remember: when it comes to coding, knowledge is power!