To give some history, Executors were only added as part of the java standard in Java 1.5. So in some ways Executors can be seen as a new better abstraction for dealing with Runnable tasks.
A bit of an over-simplification coming... - Executors are threads done right so use them in preference.
与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…