public class UserInfoService {

    public UserInfo getUserInfo(Long userId) throws InterruptedException {
        Thread.sleep(300);//模擬調(diào)用耗時(shí)
        return new UserInfo("666", "技術(shù)人成長(zhǎng)之路", 27); //一般是查數(shù)據(jù)庫(kù)，或者遠(yuǎn)程調(diào)用返回的
    }
}
public class MedalService {
    public MedalInfo getMedalInfo(long userId) throws InterruptedException {
        Thread.sleep(500); //模擬調(diào)用耗時(shí)
        return new MedalInfo("666", "守護(hù)勛章");

public class FutureTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        ExecutorService executorService = Executors.newFixedThreadPool(10);
        UserInfoService userInfoService = new UserInfoService();
        MedalService medalService = new MedalService();
        long userId =666L;
        long startTime = System.currentTimeMillis();
        //調(diào)用用戶服務(wù)獲取用戶基本信息
        FutureTask<UserInfo> userInfoFutureTask = new FutureTask<>(new Callable<UserInfo>() {
            @Override
            public UserInfo call() throws Exception {
                return userInfoService.getUserInfo(userId);
            }
        });
        executorService.submit(userInfoFutureTask);
        Thread.sleep(300); //模擬主線程其它操作耗時(shí)
        FutureTask<MedalInfo> medalInfoFutureTask = new FutureTask<>(new Callable<MedalInfo>() {
            public MedalInfo call() throws Exception {
                return medalService.getMedalInfo(userId);
        executorService.submit(medalInfoFutureTask);
        UserInfo userInfo = userInfoFutureTask.get();//獲取個(gè)人信息結(jié)果
        MedalInfo medalInfo = medalInfoFutureTask.get();//獲取勛章信息結(jié)果
        System.out.println("總共用時(shí)" + (System.currentTimeMillis() - startTime) + "ms");
    }
}

public class FutureTest {

    public static void main(String[] args) throws InterruptedException, ExecutionException, TimeoutException {
        UserInfoService userInfoService = new UserInfoService();
        MedalService medalService = new MedalService();
        long userId =666L;
        long startTime = System.currentTimeMillis();
        //調(diào)用用戶服務(wù)獲取用戶基本信息
        CompletableFuture<UserInfo> completableUserInfoFuture = CompletableFuture.supplyAsync(() -> userInfoService.getUserInfo(userId));
        Thread.sleep(300); //模擬主線程其它操作耗時(shí)
        CompletableFuture<MedalInfo> completableMedalInfoFuture = CompletableFuture.supplyAsync(() -> medalService.getMedalInfo(userId)); 
        UserInfo userInfo = completableUserInfoFuture.get(2,TimeUnit.SECONDS);//獲取個(gè)人信息結(jié)果
        MedalInfo medalInfo = completableMedalInfoFuture.get();//獲取勛章信息結(jié)果
        System.out.println("總共用時(shí)" + (System.currentTimeMillis() - startTime) + "ms");
    }
}

//使用默認(rèn)內(nèi)置線程池ForkJoinPool.commonPool()，根據(jù)supplier構(gòu)建執(zhí)行任務(wù)
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier)
//自定義線程，根據(jù)supplier構(gòu)建執(zhí)行任務(wù)
public static <U> CompletableFuture<U> supplyAsync(Supplier<U> supplier, Executor executor)

//使用默認(rèn)內(nèi)置線程池ForkJoinPool.commonPool()，根據(jù)runnable構(gòu)建執(zhí)行任務(wù)
public static CompletableFuture<Void> runAsync(Runnable runnable) 
//自定義線程，根據(jù)runnable構(gòu)建執(zhí)行任務(wù)
public static CompletableFuture<Void> runAsync(Runnable runnable,  Executor executor)

public class FutureTest {

    public static void main(String[] args) {
        //可以自定義線程池
        ExecutorService executor = Executors.newCachedThreadPool();
        //runAsync的使用
        CompletableFuture<Void> runFuture = CompletableFuture.runAsync(() -> System.out.println("run,技術(shù)人成長(zhǎng)之路"), executor);
        //supplyAsync的使用
        CompletableFuture<String> supplyFuture = CompletableFuture.supplyAsync(() -> {
                    System.out.print("supply,技術(shù)人成長(zhǎng)之路");
                    return "技術(shù)人成長(zhǎng)之路"; }, executor);
        //runAsync的future沒(méi)有返回值，輸出null
        System.out.println(runFuture.join());
        //supplyAsync的future，有返回值
        System.out.println(supplyFuture.join());
        executor.shutdown(); // 線程池需要關(guān)閉
    }
}

//輸出
run,技術(shù)人成長(zhǎng)之路
null
supply,技術(shù)人成長(zhǎng)之路技術(shù)人成長(zhǎng)之路

public CompletableFuture<Void> thenRun(Runnable action);
public CompletableFuture<Void> thenRunAsync(Runnable action);

public class FutureThenRunTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> orgFuture = CompletableFuture.supplyAsync(
                ()->{
                    System.out.println("先執(zhí)行第一個(gè)CompletableFuture方法任務(wù)");
                    return "技術(shù)人成長(zhǎng)之路";
                }
        );

        CompletableFuture thenRunFuture = orgFuture.thenRun(() -> {
            System.out.println("接著執(zhí)行第二個(gè)任務(wù)");
        });

        System.out.println(thenRunFuture.get());
    }
}

//輸出
先執(zhí)行第一個(gè)CompletableFuture方法任務(wù)
接著執(zhí)行第二個(gè)任務(wù)
null

private static final Executor asyncPool = useCommonPool ?
    ForkJoinPool.commonPool() : new ThreadPerTaskExecutor();

public CompletableFuture<Void> thenRun(Runnable action) {
    return uniRunStage(null, action);
}

public CompletableFuture<Void> thenRunAsync(Runnable action) {
    return uniRunStage(asyncPool, action);
}

public class FutureThenAcceptTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> orgFuture = CompletableFuture.supplyAsync(
                ()->{
                    System.out.println("原始CompletableFuture方法任務(wù)");
                    return "技術(shù)人成長(zhǎng)之路";
                }
        );

        CompletableFuture thenAcceptFuture = orgFuture.thenAccept((a) -> {
            if ("技術(shù)人成長(zhǎng)之路".equals(a)) {
                System.out.println("關(guān)注了");
            }

            System.out.println("先考慮考慮");
        });

        System.out.println(thenAcceptFuture.get());
    }
}

public class FutureThenApplyTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> orgFuture = CompletableFuture.supplyAsync(
                ()->{
                    System.out.println("原始CompletableFuture方法任務(wù)");
                    return "技術(shù)人成長(zhǎng)之路";
                }
        );

        CompletableFuture<String> thenApplyFuture = orgFuture.thenApply((a) -> {
            if ("技術(shù)人成長(zhǎng)之路".equals(a)) {
                return "關(guān)注了";
            }

            return "先考慮考慮";
        });

        System.out.println(thenApplyFuture.get());
    }
}

//輸出
原始CompletableFuture方法任務(wù)
關(guān)注了

public class FutureExceptionTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> orgFuture = CompletableFuture.supplyAsync(
                ()->{
                    System.out.println("當(dāng)前線程名稱：" + Thread.currentThread().getName());
                    throw new RuntimeException();
                }
        );

        CompletableFuture<String> exceptionFuture = orgFuture.exceptionally((e) -> {
            e.printStackTrace();
            return "你的程序異常啦";
        });

        System.out.println(exceptionFuture.get());
    }
}

//輸出
當(dāng)前線程名稱：ForkJoinPool.commonPool-worker-1
java.util.concurrent.CompletionException: java.lang.RuntimeException
 at java.util.concurrent.CompletableFuture.encodeThrowable(CompletableFuture.java:273)
 at java.util.concurrent.CompletableFuture.completeThrowable(CompletableFuture.java:280)
 at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1592)
 at java.util.concurrent.CompletableFuture$AsyncSupply.exec(CompletableFuture.java:1582)
 at java.util.concurrent.ForkJoinTask.doExec(ForkJoinTask.java:289)
 at java.util.concurrent.ForkJoinPool$WorkQueue.runTask(ForkJoinPool.java:1056)
 at java.util.concurrent.ForkJoinPool.runWorker(ForkJoinPool.java:1692)
 at java.util.concurrent.ForkJoinWorkerThread.run(ForkJoinWorkerThread.java:157)
Caused by: java.lang.RuntimeException
 at cn.eovie.future.FutureWhenTest.lambda$main$0(FutureWhenTest.java:13)
 at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1590)
 ... 5 more
你的程序異常啦

public class FutureWhenTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> orgFuture = CompletableFuture.supplyAsync(
                ()->{
                    System.out.println("當(dāng)前線程名稱：" + Thread.currentThread().getName());
                    try {
                        Thread.sleep(2000L);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    return "技術(shù)人成長(zhǎng)之路";
                }
        );

        CompletableFuture<String> rstFuture = orgFuture.whenComplete((a, throwable) -> {
            System.out.println("當(dāng)前線程名稱：" + Thread.currentThread().getName());
            System.out.println("上個(gè)任務(wù)執(zhí)行完啦，還把" + a + "傳過(guò)來(lái)");
            if ("技術(shù)人成長(zhǎng)之路".equals(a)) {
                System.out.println("666");
            }
            System.out.println("233333");
        });

        System.out.println(rstFuture.get());
    }
}

//輸出
當(dāng)前線程名稱：ForkJoinPool.commonPool-worker-1
當(dāng)前線程名稱：ForkJoinPool.commonPool-worker-1
上個(gè)任務(wù)執(zhí)行完啦，還把技術(shù)人成長(zhǎng)之路傳過(guò)來(lái)
666
233333
技術(shù)人成長(zhǎng)之路

public class FutureHandlerTest {

    public static void main(String[] args) throws ExecutionException, InterruptedException {
        CompletableFuture<String> orgFuture = CompletableFuture.supplyAsync(
                ()->{
                    System.out.println("當(dāng)前線程名稱：" + Thread.currentThread().getName());
                    try {
                        Thread.sleep(2000L);
                    } catch (InterruptedException e) {
                        e.printStackTrace();
                    }
                    return "技術(shù)人成長(zhǎng)之路";
                }
        );

        CompletableFuture<String> rstFuture = orgFuture.handle((a, throwable) -> {
            System.out.println("上個(gè)任務(wù)執(zhí)行完啦，還把" + a + "傳過(guò)來(lái)");
            if ("技術(shù)人成長(zhǎng)之路".equals(a)) {
                System.out.println("666");
                return "關(guān)注了";
            }
            System.out.println("233333");
            return null;
        });

        System.out.println(rstFuture.get());
    }
}

//輸出
當(dāng)前線程名稱：ForkJoinPool.commonPool-worker-1
上個(gè)任務(wù)執(zhí)行完啦，還把技術(shù)人成長(zhǎng)之路傳過(guò)來(lái)
666
關(guān)注了