How many knowledge points can a callable interface have?

Concurrent programming has always been a headache for programmers , How to write a correct concurrent program compared to other programs , It's a more difficult thing , In concurrent programming Bug It is often very strange .

The reason why concurrent programming appears Bug It's weird , Because in concurrent programming , A lot of times Bug It may not be perfectly reproduced , in other words , Concurrent programming Bug It's hard to reproduce , Hard to track .

today , The glacier brought the little friends back again Callable Interface , Okay , Let's get to the point .

This article is pure dry goods , In depth analysis from the perspective of source code Callable Interface , I hope you will step down , Open your IDE, Follow the article to see the source code , I believe you will gain a lot .

Callable The interface is introduced

Callable Interface is JDK1.5 New generic interface , stay JDK1.8 in , Declared as a functional interface , As shown below .

@FunctionalInterface
public interface Callable<V> {
    V call() throws Exception;
}

stay JDK 1.8 Only one method's interface is declared as a functional interface in , Functional interfaces can be used @FunctionalInterface To modify , You can also not use @FunctionalInterface To modify . As long as an interface contains only one method , that , This interface is a functional interface .

stay JDK in , Realization Callable The subclass of the interface is shown in the figure below .

The default subclass hierarchy diagram is not clear , here , Can pass IDEA Right click Callable Interface , choice “Layout” To specify the Callable Interface implementation, different structure of class diagram , As shown below .

here , You can choose “Organic Layout” Options , After selection Callable The structure of subclasses of interfaces is shown in the figure below .

In the realization of Callable In subclasses of interfaces , There are several important classes , As shown in the figure below .