public boolean checkApk(String packageName) { 

    if (packageName == null || "".equals(packageName)) 

        return false; 

    try { 

        ApplicationInfo info = getPackageManager().getApplicationInfo( 

                packageName, PackageManager.GET_UNINSTALLED_PACKAGES); 

        return true; 

    } catch (NameNotFoundException e) { 

        return false; 

    } 

}