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在Kotlin的另一个线程中运行room insert的推荐方法

android-room kotlin android

Alin · 技术社区 · 6 年前

我在台阶上 Repository 我想实现跑步 @Insert 进入新线程,而不是在UI线程上。

我发现有几种方法可以解决这个问题:

一些样品的使用 AsyncTask 并且在 doInBackground 做 Dao 呼叫
谷歌向日葵样本使用 runOnIoThread 哪种方法可以 IO_EXECUTOR.execute(job) 哪里 IO_EXECUTOR = Executors.newSingleThreadExecutor
有些似乎有用 anko

doAsync{ dao.insert(item) }

推荐的方法是什么?

1 回复 | 直到 6 年前

EpicPandaForce 6 年前

通常,您应该在一个接口下包装自己的执行器。

public interface Scheduler {
    void runOnThread(Runnable runnable);
}

/**
 * A Scheduler implementation based on ModernAsyncTask with an unbounded task queue.
 **/
public class IoScheduler implements Scheduler {
    private static final int CORE_POOL_SIZE = 5;
    private static final int MAXIMUM_POOL_SIZE = 128;
    private static final int KEEP_ALIVE = 1;

    private static final ThreadFactory sThreadFactory = new ThreadFactory() {
        private final AtomicInteger mCount = new AtomicInteger(1);

        @Override
        public Thread newThread(Runnable r) {
            return new Thread(r, "IoScheduler #" + mCount.getAndIncrement());
        }
    };

    private static final BlockingQueue<Runnable> sPoolWorkQueue =
            new LinkedBlockingQueue<Runnable>();

    /**
     * An {@link Executor} that can be used to execute tasks in parallel.
     */
    private static final Executor THREAD_POOL_EXECUTOR =
         new ThreadPoolExecutor(CORE_POOL_SIZE, MAXIMUM_POOL_SIZE, KEEP_ALIVE,
                 TimeUnit.SECONDS, sPoolWorkQueue, sThreadFactory);

    @Override
    public void runOnThread(Runnable runnable) {
        THREAD_POOL_EXECUTOR.execute(runnable);
    }
}

你通常会用匕首:

@Singleton
public class IoScheduler implements Scheduler {
    @Inject
    IoScheduler() {}
    ...
}

@Module
public class SchedulerModule {
    public static final String BACKGROUND = "BACKGROUND";

    @Named(BACKGROUND) // you can also use @Qualifier
    @Provides
    Scheduler ioScheduler(IoScheduler ioScheduler) {
        return ioScheduler;
    }
}

然后在其他地方使用

@Singleton
public class MyService {
    private final Scheduler ioScheduler;

    @Inject
    MyService(@Named(SchedulerModule.BACKGROUND) Scheduler ioScheduler) { // you can use @Qualifier here instead of @Named
        this.ioScheduler = ioScheduler;
    }
    ....
}

(尽管如此 ioScheduler 更适合读:对于写操作,您可能需要考虑一个单独的单线程执行器。)

所以如果你读到它的结尾,它实际上是这样的方法:

2.)谷歌向日葵样本使用 runOnIoThread 哪种方法可以 IO_EXECUTOR.execute(job) 哪里 IO_EXECUTOR = Executors.newSingleThreadExecutor