接下来我们看看task模块下有哪些类。
屏幕快照 2018-01-28 14.35.02.png
- Priority类，是一个枚举类定义了一些级别
public enum Priority {
UI_TOP,
UI_NORMAL,
UI_LOW,
DEFAULT,
BG_TOP,
BG_NORMAL,
BG_LOW;
}
- TaskHandler定义了一些接口。
public interface TaskHandler {
boolean supportPause();
boolean supportResume();
boolean supportCancel();
void pause();
void resume();
void cancel();
boolean isPaused();
boolean isCancelled();
}
- PriorityObject，就是给一个对象加上一个优先级而已。
public class PriorityObject<E> {
public final Priority priority;
public final E obj;
public PriorityObject(Priority priority, E obj) {
this.priority = priority == null ? Priority.DEFAULT : priority;
this.obj = obj;
}
}
- PriorityRunnable 带有优先级的一个Runnable
public class PriorityRunnable extends PriorityObject<Runnable> implements Runnable {
public PriorityRunnable(Priority priority, Runnable obj) {
super(priority, obj);
}
@Override
public void run() {
this.obj.run();
}
}
-
PriorityExecutor ，就是自定义了一个线程池
屏幕快照 2018-01-28 14.46.57.png
public class PriorityExecutor implements Executor {
private static final ThreadFactory sThreadFactory = new ThreadFactory() {
private final AtomicInteger mCount = new AtomicInteger(1);
@Override
public Thread newThread(Runnable r) {
return new Thread(r, "PriorityExecutor #" + mCount.getAndIncrement());
}
};
private final BlockingQueue<Runnable> mPoolWorkQueue = new PriorityObjectBlockingQueue<Runnable>();
private final ThreadPoolExecutor mThreadPoolExecutor;
public PriorityExecutor() {
this(CORE_POOL_SIZE);
}
public PriorityExecutor(int poolSize) {
mThreadPoolExecutor = new ThreadPoolExecutor(
poolSize,
MAXIMUM_POOL_SIZE,
KEEP_ALIVE,
TimeUnit.SECONDS,
mPoolWorkQueue,
sThreadFactory);
}
public boolean isBusy() {
return mThreadPoolExecutor.getActiveCount() >= mThreadPoolExecutor.getCorePoolSize();
}
}
PriorityAsyncTask 可以类比AsyncTask源码分析,其实就是加上了Priority属性，线程池换了PriorityExecutor，再次就不多说了。
PriorityObjectBlockingQueue，在xUtils3 里面将其修改为PriorityBlockingQueue。【死磕Java并发】-----J.U.C之阻塞队列：PriorityBlockingQueue,以及JUC源码分析-集合篇（七）：PriorityBlockingQueue
