How do I check if an app is a non-system app in Android?

Question

I am getting a list of ApplicationInfo Objects with packageManager.getInstalledApplications(0) and attempting to categorize them by whether or not they are a sy

Answer 1

I was under the impression that all apps in the system image are system apps (and normally installed in /system/app).

If FLAG_SYSTEM is only set to system applications, this will work even for apps in external storage:

boolean isUserApp(ApplicationInfo ai) {
    int mask = ApplicationInfo.FLAG_SYSTEM | ApplicationInfo.FLAG_UPDATED_SYSTEM_APP;
    return (ai.flags & mask) == 0;
}

An alternative is to use the pm command-line program in your phone.

Syntax:

pm list packages [-f] [-d] [-e] [-s] [-3] [-i] [-u] [--user USER_ID] [FILTER]

pm list packages: prints all packages, optionally only
  those whose package name contains the text in FILTER.  Options:
    -f: see their associated file.
    -d: filter to only show disbled packages.
    -e: filter to only show enabled packages.
    -s: filter to only show system packages.
    -3: filter to only show third party packages.
    -i: see the installer for the packages.
    -u: also include uninstalled packages.

Code:

ProcessBuilder builder = new ProcessBuilder("pm", "list", "packages", "-s");
Process process = builder.start();

InputStream in = process.getInputStream();
Scanner scanner = new Scanner(in);
Pattern pattern = Pattern.compile("^package:.+");
int skip = "package:".length();

Set systemApps = new HashSet();
while (scanner.hasNext(pattern)) {
    String pckg = scanner.next().substring(skip);
    systemApps.add(pckg);
}

scanner.close();
process.destroy();

Then:

boolean isUserApp(String pckg) {
    return !mSystemApps.contains(pckg);
}