execute和submit的区别
相同点：
1 都可以执行任务
2 参数都支持runnable
submit
execute
从图中可以看到两者的区别如下：
(1)来源
execute是Executor接口中的方法
submit是AbstractExecutorService中的方法
(2)接收参数类型
execute只能接受Runnable类型的任务
submit不管是Runnable还是Callable类型的任务都可以接受，但是Runnable返回值均为void，所以使用Future的get()获得的还是null
(3)返回值
execute没有返回值
submit有返回值，所以需要返回值的时候必须使用submit
(4)异常
execute中的是Runnable接口的实现，所以只能使用try、catch来捕获CheckedException，通过实现UncaughtExceptionHande接口处理UncheckedException
不管提交的是Runnable还是Callable类型的任务，如果不对返回值Future调用get()方法，都会吃掉异常。
package executors.threadpool;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.LinkedBlockingDeque;
import java.util.concurrent.ThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
/**
* <p></p>
*
* @author : wangdejian
* @version 1.0
* @date : 2021/8/4 21:01
*/
public class ThreadPoolExecute {
public static void main(String[] args) {
myTask();
}
public static void myTask() {
ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(2,
5,
5,
TimeUnit.MINUTES,
new ArrayBlockingQueue<>(6));
for (int i = 0; i < 12; i++) {
int tmp = i;
threadPoolExecutor.execute(() -> {
try {
System.out.println("--->" + Thread.currentThread().getName() + "--" + tmp);
Thread.sleep(1_000);
} catch (InterruptedException e) {
e.printStackTrace();
}
});
}
threadPoolExecutor.shutdown();
}
}
public class ThreadPoolSubmit {
public static void main(String[] args) throws ExecutionException, InterruptedException {
Callable<Map<String, String>> callable = () -> {
Map<String, String> map = new HashMap<>();
try {
Thread.sleep(1_000);
} catch (InterruptedException e) {
e.printStackTrace();
}
String toString = Thread.currentThread().toString();
String name = Thread.currentThread().getName();
System.out.println("toString=" + toString + ";name=" + name);
map.put("toString", Thread.currentThread().toString());
map.put("name", name);
return map;
};
ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(5, 10,
5, TimeUnit.MINUTES,
new ArrayBlockingQueue<Runnable>(10));
for (int i = 0; i < 10; i++) {
Future<Map<String, String>> submit = threadPoolExecutor.submit(callable);
System.out.println(submit.get().get("name"));
System.out.println(submit.get().get("toString"));
}
}
}
