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JavaAdvanced#concurrency
JavaIntermediate#concurrency
What is the difference between Callable and Runnable?
Runnable.run() returns void and cannot throw checked exceptions. Callable.call() returns a value and can throw checked exceptions; used with ExecutorService for Futures.
Example
Callable<Integer> task = () -> { return 42; };
Runnable r = () -> System.out.println("no return value");