How to Clear Cache of all other Installed applications in android

Question

I want to clear the cache memory of all other installed applications. Please provide me some solution of the problem.

Answer 1

The simple answer:

You can't.

The more complex/accurate answer:

There is permission android.permission.GET_TASKS that is a signature-level permission that can allow an app to do this. However, as it is a signature-level permission it means it can only be used in system/firmware apps.

Edit:

I seem to have misinterpreted the question - the above is valid if you are trying to clear cached applications (i.e. recent apps)

To clear all installed application's caches the answer below (based off this previous answer) is apparently correct - please note the answer there incorrect tries to call freeStorage and not freeStorageAndNotify in the reflection:

PackageManager  pm = getPackageManager();
// Get all methods on the PackageManager
Method[] methods = pm.getClass().getDeclaredMethods();
for (Method m : methods) {
    if (m.getName().equals("freeStorageAndNotify")) {
        // Found the method I want to use
        try {
            long desiredFreeStorage = 8 * 1024 * 1024 * 1024; // Request for 8GB of free space
            m.invoke(pm, desiredFreeStorage , null);
        } catch (Exception e) {
            // Method invocation failed. Could be a permission problem
        }
        break;
    }
}

Also make sure to add the following permission to your AndroidManifest.xml:

<uses-permission android:name="android.permission.CLEAR_APP_CACHE"/>