本文共 4052 字，大约阅读时间需要 13 分钟。

PriorityThreadFactory.java

import java.util.concurrent.ThreadFactory;class PriorityThreadFactory implements ThreadFactory {       private final int mThreadPriority;    public PriorityThreadFactory(int threadPriority) {           mThreadPriority = threadPriority;    }    @Override    public Thread newThread(final Runnable runnable) {           Runnable wrapperRunnable = new Runnable() {               @Override            public void run() {                   try {                       android.os.Process.setThreadPriority(mThreadPriority);                } catch (Throwable t) {                   }                runnable.run();            }        };        return new Thread(wrapperRunnable);    }}

MainThreadExecutor.java

import android.os.Handler;import android.os.Looper;import java.util.concurrent.Executor;class MainThreadExecutor implements Executor {       private final Handler handler = new Handler(Looper.getMainLooper());    @Override    public void execute(Runnable runnable) {           handler.post(runnable);    }}

DefaultExecutorSupplier.java

import java.util.concurrent.Executor;import java.util.concurrent.LinkedBlockingQueue;import java.util.concurrent.ThreadFactory;import java.util.concurrent.ThreadPoolExecutor;import java.util.concurrent.TimeUnit;public class DefaultExecutorSupplier {       public static final int NUMBER_OF_CORES = Runtime.getRuntime().availableProcessors();    private final ThreadPoolExecutor mForBackgroundTasks;    private final ThreadPoolExecutor mForLightWeightBackgroundTasks;    private final Executor mMainThreadExecutor;    private static DefaultExecutorSupplier sInstance;    public static DefaultExecutorSupplier getInstance() {           if (sInstance == null) {               synchronized (DefaultExecutorSupplier.class) {                   sInstance = new DefaultExecutorSupplier();            }        }        return sInstance;    }    private DefaultExecutorSupplier() {           ThreadFactory backgroundPriorityThreadFactory = new PriorityThreadFactory(android.os.Process.THREAD_PRIORITY_BACKGROUND);        mForBackgroundTasks = new ThreadPoolExecutor(                NUMBER_OF_CORES * 2,                NUMBER_OF_CORES * 2,                60L,                TimeUnit.SECONDS,                new LinkedBlockingQueue
   
    (),                backgroundPriorityThreadFactory        );        mForLightWeightBackgroundTasks = new ThreadPoolExecutor(                NUMBER_OF_CORES * 2,                NUMBER_OF_CORES * 2,                60L,                TimeUnit.SECONDS,                new LinkedBlockingQueue
    
     (),                backgroundPriorityThreadFactory        );        mMainThreadExecutor = new MainThreadExecutor();    }    public ThreadPoolExecutor forBackgroundTasks() {           return mForBackgroundTasks;    }    public ThreadPoolExecutor forLightWeightBackgroundTasks() {           return mForLightWeightBackgroundTasks;    }    public Executor forMainThreadTasks() {           return mMainThreadExecutor;    }    //demo    public void doSomeBackgroundWork() {           DefaultExecutorSupplier.getInstance().forBackgroundTasks()                .execute(new Runnable() {                       @Override                    public void run() {                           // do some background work here.                    }                });    }    //demo    public void doSomeLightWeightBackgroundWork() {           DefaultExecutorSupplier.getInstance().forLightWeightBackgroundTasks()                .execute(new Runnable() {                       @Override                    public void run() {                           // do some light-weight background work here.                    }                });    }    //demo    public void doSomeMainThreadWork() {           DefaultExecutorSupplier.getInstance().forMainThreadTasks()                .execute(new Runnable() {                       @Override                    public void run() {                           // do some Main Thread work here.                    }                });    }}