Java.Multithreding.What is the difference between interrupted() and isInterrupted()?

🧠 interrupted() vs isInterrupted()

Method	Static?	Clears Interrupt Flag?	Checks Which Thread?
Thread.interrupted()	✅ Yes	✅ Yes (resets to false)	Current thread only
isInterrupted()	❌ No	❌ No	Any specific thread object

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✅ Thread.interrupted()

• Static method
• Checks the interrupted status of the current thread
• Clears the flag after checking (resets it to false)

Example:

Thread.currentThread().interrupt();         // Set the interrupt flag
System.out.println(Thread.interrupted());  // true (and resets the flag)
System.out.println(Thread.interrupted());  // false (already cleared)

Use this if you’re inside a thread and want to check and clear the flag in one go.

✅ isInterrupted()

• Instance method
• Checks the interrupt status of a specific thread
• Does not clear the flag

Example:

Thread t = new Thread(() -> {
    while (!Thread.currentThread().isInterrupted()) {
        // do work
    }
    System.out.println("Thread interrupted!");
});
t.start();

Thread.sleep(1000);
t.interrupt(); // Sets interrupt flag

System.out.println(t.isInterrupted()); // true

Use this if you want to monitor or log whether a thread was interrupted — without affecting its flag.

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🔁 Real-World Analogy

Think of the interrupt flag like a “Do Not Disturb” sign:

Method	Behavior
interrupted()	You peek at the sign and take it down
isInterrupted()	You peek at the sign, but leave it up

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🧠 Summary

Feature	interrupted()	isInterrupted()
Static	✅ Yes	❌ No
Checks current thread	✅ Only	❌ Must specify thread
Clears interrupt flag	✅ Yes	❌ No
Best for	Checking + clearing in loops	Monitoring thread externally