I get exception when using Thread.sleep(x) or wait()

Why InterruptedException needs to be handled

An in-depth understanding of InterruptedException forms the core of effective multitasking in Java. When a thread is in sleep or wait mode, an interruption can be signalled to change its course. This interruption manifests as an exceptional event in Java named InterruptedException.

Preserving the interrupt status

Throwing InterruptedException clears the interrupted status of the thread. However, it is a vital piece of information that should not be lost. To preserve this information and respect the thread interruption policy, use Thread.currentThread().interrupt(). This restores the interrupt status allowing further handling.

Tuning sleep durations with TimeUnit

Instead of manually converting units of time, consider using the TimeUnit enum in Java. This promotes readability and precision in defining sleep durations:

TimeUnit.SECONDS.sleep(5);        				 // A 5-second coffee break
TimeUnit.MINUTES.sleep(2);        				 // Enough time to check messages
TimeUnit.DAYS.sleep(1);        					// Fallout vault experiment, let's emerge tomorrow!
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Managing InterruptedException effectively: A guide

As the adage goes, "Exceptions happen!" So, let's look at ways to efficiently deal with InterruptedException.

Catch it or declare it: Handling InterruptedException

Java obliges us to acknowledge the possibility of InterruptedException either by catching or declaring it in the method's signature.

public void takeANap() throws InterruptedException {
    // Hope no one interrupts!
}
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Keep a log: Track your InterruptedExceptions

In line with good coding practices, any InterruptedException caught should be logged. This helps in tracing who is interrupting and why.

catch (InterruptedException e) {
    Logger.getLogger(MyClass.class.getName()).log(Level.SEVERE, null, e);
    Thread.currentThread().interrupt();			// Who woke me up?!
}
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Cleanup is a must

While handling InterruptedException, remember to clean up any resources used prior to the event. This should preferably be done in a finally block or using a try-with-resources statement to prevent resource leaks.

try {
    // Sensitive operations
} catch (InterruptedException e) {
    Thread.currentThread().interrupt();
} finally {
    // Clean as you go
}
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Multi-threading tips for efficient and reliable coding

Given that InterruptedException is a crucial part of JVM's multi-threading mechanism, let's delve into principles that make multi-threading in Java reliable and robust.

Reduce shared mutable state

Try to keep shared mutable variables to a minimum, reducing the likelihood of race conditions and deadlocks.

Leverage higher-level concurrency utilities

When it comes to dealing with Java’s low-level wait(), notify(), interrupt() primitives, they are hard to use correctly. Java provides high-level utility packages such as java.util.concurrent which are much easy to use and robust.

Immutable is adorable

Immutable objects can't be modified after they're created and hence are naturally thread-safe. The more you use them, the simpler and safer your code becomes!