Refactor to read/write files of graph and map data

src/main/java/GraphDataObjectWriter.java

@@ -0,0 +1,27 @@
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectOutputStream;
+
+public class GraphDataObjectWriter {
+
+    private GraphWithMapData data;
+    private String filename;
+
+    public GraphDataObjectWriter(String filename, GraphWithMapData data) {
+        if(!filename.matches(".*\\.ser")){
+            filename = filename + ".ser";
+        }
+        this.filename = filename;
+        this.data = data;
+    }
+
+    public void writeDataToFile() {
+        try (FileOutputStream fileOut = new FileOutputStream(filename);
+             ObjectOutputStream out = new ObjectOutputStream(fileOut);
+        ){
+            out.writeObject(data);
+        } catch (IOException ex) {
+            ex.printStackTrace();
+        }
+    }
+}