moved XML submodule to resources

.gitmodules

@@ -1,3 +1,3 @@
-[submodule "APED/app/src/main/java/com/example/aped/xml"]
-	path = APED/app/src/main/java/com/example/aped/xml
+[submodule "APED/app/src/main/res/raw/XML"]
+	path = APED/app/src/main/res/raw/XML
 	url = https://its-gitlab.init.hs-owl.de/mo_b_l/aped_xml_configs.git

APED/app/src/main/java/com/example/aped/utils/ExternalStorageHandler.java

@@ -0,0 +1,53 @@
+package com.example.aped.utils;
+
+import android.content.Context;
+import android.os.Environment;
+
+import java.io.File;
+import java.io.FileNotFoundException;
+
+/**
+ * Utility for getting information related to the external storage.
+ */
+public final class ExternalStorageHandler {
+
+    private ExternalStorageHandler() { }
+
+    /**
+     * Checks whether the external storage is mounted.
+     * @return boolean value
+     */
+    public static boolean isExternalStorageMounted() {
+        return Environment.MEDIA_MOUNTED.equals(
+                Environment.getExternalStorageState()
+        );
+    }
+
+    /**
+     * Checks whether the external storage is read only.
+     * @return boolean value
+     */
+    public static boolean isExternalStorageReadOnly() {
+        return Environment.MEDIA_MOUNTED_READ_ONLY.equals(
+                Environment.getExternalStorageState()
+        );
+    }
+
+    /**
+     * Returns the external private storage base directory path for an activity.
+     * @param context the relevant activity
+     * @return the path to the base of the external private storage
+     * @throws FileNotFoundException checks if the directory is mounted
+     */
+    public static String getExternalPrivateStorageDir(final Context context)
+            throws FileNotFoundException {
+        if (isExternalStorageMounted()) {
+            File file = context.getExternalCacheDir();
+            return file.getAbsolutePath();
+        } else {
+            throw new FileNotFoundException(
+                    "The relevant storage is not available."
+            );
+        }
+    }
+}

APED/app/src/main/java/com/example/aped/xml

@@ -1 +0,0 @@
-Subproject commit 3600828925b4f02fcf472797c5cf526d24f53f63

APED/app/src/main/res/raw/XML

@@ -0,0 +1 @@
+Subproject commit ce8ce41609a1a7ef9282cbcdda3358f9c2ec6939