如何在 Android 中使用 Accessibility Service 删除缓存？

Question

I'm working on cache cleaner app, after doing research on google I found that Android system has moved "CLEAR_APP_CACHE" permission to "signature, privileged" state. So I'm unable clear cache with freeStorageAndNotify method.

Apps on google playstore like CCleaner , Power Clean etc.. are using Accessibility Service To Delete Cache.

I have also created basic accessibility service for my app, but don't know how to delete cache of apps

Answer 1

You can get a list of installed apps and delete cache like:

    public static void clearALLCache()
            {
                List<PackageInfo> packList = getPackageManager().getInstalledPackages(0);
            for (int i=0; i < packList.size(); i++)
            {
                PackageInfo packInfo = packList.get(i);
                if (  (packInfo.applicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) == 0)
                {
                    String appName = packInfo.applicationInfo.loadLabel(getPackageManager()).toString();
                    try {
                        // clearing app data
    //                    Runtime runtime = Runtime.getRuntime();
    //                    runtime.exec("pm clear "+packInfo.packageName);
                        Context context = getApplicationContext().createPackageContext(packInfo.packageName,Context.CONTEXT_IGNORE_SECURITY);
                        deleteCache(context);

                    } catch (Exception e) {
                        e.printStackTrace();
                    }
                }
            }
            }

public static void deleteCache(Context context) {
        try {
            File dir = context.getCacheDir();
            deleteDir(dir);
        } catch (Exception e) {}
    }

    public static boolean deleteDir(File dir) {
        if (dir != null && dir.isDirectory()) {
            String[] children = dir.list();
            for (int i = 0; i < children.length; i++) {
                boolean success = deleteDir(new File(dir, children[i]));
                if (!success) {
                    return false;
                }
            }
            return dir.delete();
        } else if(dir!= null && dir.isFile()) {
            return dir.delete();
        } else {
            return false;
        }
    }

It is equivalent to clear data option under Settings --> Application Manager --> Your App --> Clear data. (In comment)

For making your application support this you should also follow Privileged Permission Whitelisting from google