ADD: SimpleAsyncTask.

library/src/main/java/com/oasisfeng/android/os/SimpleAsyncTask.java

@@ -0,0 +1,53 @@
+package com.oasisfeng.android.os;
+
+import android.os.AsyncTask;
+import android.support.annotation.MainThread;
+import android.support.annotation.WorkerThread;
+
+import com.google.common.base.Supplier;
+import com.oasisfeng.android.util.Consumer;
+
+import java.util.concurrent.Callable;
+
+/**
+ * Simplify the basic usage of {@link AsyncTask}.
+ *
+ * Created by Oasis on 2016/11/6.
+ */
+public abstract class SimpleAsyncTask extends AsyncTask<Void, Void, Void> {
+
+	@MainThread public static void execute(final Runnable do_in_background, final Runnable on_post_execute) {
+		new SimpleAsyncTask() {
+			@Override protected void doInBackground() { do_in_background.run(); }
+			@Override protected void onPostExecute() { on_post_execute.run(); }
+		}.execute();
+	}
+
+	/** Execute background task and deal with the result in post-execute procedure */
+	@MainThread public static <T> void execute(final Supplier<T> do_in_background, final Consumer<T> on_post_execute) {
+		new AsyncTask<Void, Void, T>() {
+			@Override protected T doInBackground(final Void... params) { return do_in_background.get(); }
+			@Override protected void onPostExecute(final T result) { on_post_execute.accept(result); }
+		}.execute();
+	}
+
+	/** Execute background task with possible exception caught in post-execute procedure */
+	@MainThread public static void execute(final Callable<Exception> do_in_background, final Consumer<Exception> on_post_execute) {
+		new AsyncTask<Void, Void, Exception>() {
+			@Override protected Exception doInBackground(final Void... params) {
+				try {
+					return do_in_background.call();
+				} catch (final Exception e) {
+					return e;
+				}
+			}
+			@Override protected void onPostExecute(final Exception result) { on_post_execute.accept(result); }
+		}.execute();
+	}
+
+	@WorkerThread protected abstract void doInBackground();
+	@MainThread protected abstract void onPostExecute();
+
+	@Override @WorkerThread protected final Void doInBackground(final Void... params) { doInBackground(); return null; }
+	@Override @MainThread protected final void onPostExecute(final Void aVoid) { onPostExecute(); }
+}