CompletableFuture CompletableFuture.supplyAsync 异常处理

Posted 2020-10-22 高因咖啡

CompletableFuture 异常处理completeExceptionally可以把异常抛到主线程

/**
 * User: laizhenwei
 * Date: 2018-01-30 Time: 22:26
 * Description:
 */
@RunWith(SpringRunner.class)
//@SpringBootTest
public class CompletableFutureTests {

    @Test
    public void testMethod() {

        String[] orders = {"1", "2", "3", "4", "5", "6"};

        List<CompletableFuture<Boolean>> futures = new ArrayList<>();

        Arrays.stream(orders).forEach(id -> {
            try{
                futures.add(submitAsync(id));
            }catch (Exception ex){
                System.out.println(ex);
            }
        });

        futures.stream().forEach(f-> {
            try {
                System.out.println(f.get());
            } catch (Exception e) {
                e.printStackTrace();
            }
        });
    }

    private static Boolean submit(String order) {
        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        throw new RuntimeException("抛一个异常" + order);
    }

    private static CompletableFuture<Boolean> submitAsync(String order) {
        CompletableFuture<Boolean> future = new CompletableFuture<>();
        new Thread(() -> {
            try {
                Boolean result = submit(order);
                future.complete(result);
            } catch (Exception ex) {
                future.completeExceptionally(ex);
            }
        }).start();
        return future;
    }

}

 

使用 CompletableFuture.supplyAsync  简化代码 加入线程池,exceptionally处理异常

/**
 * User: laizhenwei
 * Date: 2018-01-30 Time: 22:26
 * Description:
 */
@RunWith(SpringRunner.class)
//@SpringBootTest
public class CompletableFutureTests {

    ExecutorService executor = Executors.newFixedThreadPool(3);

    @Test
    public void testMethod() {
        String[] orders = {"1", "2", "3", "4", "5", "6"};
        Arrays.stream(orders).forEach(id -> CompletableFuture.supplyAsync(() -> submit(id), executor).exceptionally(e -> {
            System.out.println(e);
            return false;
        }));

        executor.shutdown();
        while (!executor.isTerminated()) {
            try {
                TimeUnit.MILLISECONDS.sleep(500);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    private static Boolean submit(String order) {
        try {
            TimeUnit.SECONDS.sleep(1);
        } catch (InterruptedException e) {
            e.printStackTrace();
        }
        throw new RuntimeException("抛一个异常" + order);
    }

}