Android Support Library Media Compat's asynchronous loading and cache strategy
Android Support Library MediaCompat is a support library of Android, which provides multimedia functions with consistency on different versions.Among them, asynchronous loading and cache strategies are a very important part of MediaCompat.In this article, we will thoroughly study the asynchronous loading and cache strategies in the MediaComPat support library, and provide relevant Java code examples.
1. Asynchronous loading strategy
1. Use asynchronous tasks to load media resources: In Android, using asynchronous tasks to load media resources is a common way.Generally, we can create a subclass that inherit AsyncTask and perform loading operations in the background thread.The following is an example:
public class MediaLoaderTask extends AsyncTask<String, Void, Bitmap> {
private ImageView imageView;
public MediaLoaderTask(ImageView imageView) {
this.imageView = imageView;
}
@Override
protected Bitmap doInBackground(String... params) {
String url = params[0];
// Execute the operation of loading media resources, such as obtaining data from the Internet or local storage
// Back to the loaded media resource BITMAP object
}
@Override
protected void onPostExecute(Bitmap result) {
super.onPostExecute(result);
if (result != null) {
imageView.setImageBitmap(result);
}
}
}
2. Use the thread pool to load media resources: In order to better manage the loading operation, we can use the thread pool to load media resources.Android provides an Executor framework that can easily manage the thread pool.The following is an example:
ExecutorService executor = Executors.newFixedThreadPool(4);
public void loadMediaResource(final String url, final ImageView imageView) {
executor.execute(new Runnable() {
@Override
public void run() {
Bitmap bitmap = loadBitmapFromUrl(url);
if (bitmap != null) {
imageView.post(new Runnable() {
@Override
public void run() {
imageView.setImageBitmap(bitmap);
}
});
}
}
});
}
3. Use a third -party library to load media resources: In addition to using the asynchronous loading method provided by Android, we can also use some third -party libraries to load media resources, such as Glide, Picasso, etc.These libraries provide richer function and more efficient cache strategies, which can greatly simplify our development work.
Second, cache strategy
1. Memory cache: Use memory cache to quickly load the media resources that have been loaded before.Android Support Library MediaCompat provides a simple memory cache interface that can manage the cache by setting the appropriate cache size.
MemoryCache cache = new MemoryCache();
public void loadMediaResource(String url, ImageView imageView) {
Bitmap bitmap = cache.get(url);
if (bitmap != null) {
imageView.setImageBitmap(bitmap);
} else {
// If there is no media resource in the memory cache, the loading operation is performed
// After loading, save it into the memory cache
cache.put(url, loadedBitmap);
}
}
2. Disk cache: Disk cache is an important cache strategy that can greatly reduce dependence on the network and provide offline access ability.Android Support Library MediaCompat does not provide a direct disk cache function, but we can use other third -party libraries, such as DiskLRUCACHE, etc. to achieve disk cache function.
DiskLruCache diskCache = DiskLruCache.open(cacheDir, APP_VERSION, VALUE_COUNT, MAX_SIZE);
public void loadMediaResource(String url, ImageView imageView) {
String key = Utility.hashKeyFromUrl(url);
DiskLruCache.Snapshot snapshot = diskCache.get(key);
if (snapshot != null) {
// If the media resource exists in the disk cache, obtain
// If it does not exist, execute the loading operation and save the loaded results in the disk cache
// Then get and display from the disk cache
Bitmap bitmap = getBitmapFromInputStream(snapshot.getInputStream(0));
imageView.setImageBitmap(bitmap);
} else {
// If there is no media resource in the disk cache, the loading operation is executed
// After loading, save it into the disk cache
diskCache.put(key, bitmap);
}
}
3. Conclusion
Android Support Library MediaCompat provides a powerful asynchronous loading and cache strategy to help us quickly and effectively load media resources.By using these strategies reasonably and combining the functions of other third -party libraries, we can improve the user experience, reduce network dependence, and improve the performance of the application.
I hope that this article can understand the asynchronous loading and cache strategies of Android Support Library MediaCompat and provide guidance for you in development.
