Multithreading-through callable implementation (30)

Video: https://edu.aliyun.com/course/36/learn?spm=5176.8764728.0.0.fVZ5cb#lesson/433

1. Starting with JDK1.5, a new development package has been added: Java.util.concurrent, the development package is primarily for high-performance programming, which provides classes that will be used in high concurrency operations in this development package. Within this package there is a new interface defined:

 Public Interface Callable<v> {    publicthrows  Exception;}

Although the run () method in Runnable is also the main method of the thread, it does not return a value because its design follows the principle of the main method, that is, the thread starts and does not look back. However, there are a number of times when a return value is required, such as when certain threads are executed, which can result in some return, which can only be done through callable. (Description in JDK: Thecallable interface is similar in Runnable that both are designed for classes whose instances might be executed by another thread.) However, Runnable does not return a result and cannot throw a checked exception. ）

Example: Defining a thread principal class using callable

class Implements Callable<string>{    @Override    publicthrows  Exception {          for (int x=0;x<20;x++) {                System.out.println ("Sell ticket, X" +x);        }         return "The ticket is sold out";    }}   // this is the principal class of a thread.

public class MyThread222 {
public static void Main (string[] args) {

}
}

In either case, if you want to start multithreading only the Thread class's start () method,

Multithreading-through callable implementation (in)