使用java线程池的一个例子

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;

public class ThreadPoolDemo {

public static void main(String[] args) throws InterruptedException, ExecutionException {
ExecutorService es = Executors.newFixedThreadPool(3);
List<Future<String>> resultList = new ArrayList<>();
for (int i = 0; i < 10; i++) {
int num = i;
resultList.add(es.submit(new Callable<String>() {
@Override
public String call() throws Exception {
Thread.sleep(5000);
return "task " + num + " completed.";
}
}));
}
es.shutdown();

for (Future<String> res : resultList) {
System.out.println(res.get());
}
}
}

task 0 completed.
task 1 completed.
task 2 completed.
task 3 completed.
task 4 completed.
task 5 completed.
task 6 completed.
task 7 completed.
task 8 completed.
task 9 completed.