made changes to Storage.java

Author: huixianc

data/duke.txt

@@ -2,6 +2,6 @@ T | 1 | read book
 D | 1 | return book | 2pm | 2020-02-01
 D | 0 | submit code | 5pm | 2020-01-30
 E | 0 | meeting | 8am | 2020-01-30
-T | 0 |  nap
+T | 0 | nap
 E | 0 | meeting | 1pm | 2020-02-01
 D | 0 | tutorial | 2pm | 2020-02-02

src/main/java/Duke.java

@@ -15,10 +15,10 @@ public Duke(String filePath) {
         // following code from module website
 
         ui = new Ui();
-        storage = new Storage(filePath);
         parser = new Parser();
 
         try {
+            storage = new Storage(filePath);
             tasks = new TaskList(storage.load());
         } catch (DukeException e) {
             ui.showError(e);
@@ -28,7 +28,7 @@ public Duke(String filePath) {
 
     public void run() {
         // following code from module website
-        
+
         ui.greet();
 
         boolean isExit = false;

src/main/java/META-INF/MANIFEST.MF

@@ -0,0 +1,3 @@
+Manifest-Version: 1.0
+Main-Class: Duke
+

src/main/java/duke/pack/Storage.java

@@ -12,9 +12,18 @@ public class Storage {
     protected String filePath;
     protected File file;
 
-    public Storage(String filePath) {
+    public Storage(String filePath) throws DukeException {
         this.filePath = filePath;
+
+        // file creation following code from
+        // https://stackoverflow.com/questions/6142901/how-to-create-a-file-in-a-directory-in-java/6143076#6143076
         file = new File(filePath);
+        try {
+            file.getParentFile().mkdirs();
+            file.createNewFile();
+        } catch (IOException e) {
+            throw new DukeException("    Oh no, file could not be created!\n");
+        }
     }
 
     public ArrayList<Task> load() throws DukeException {