From 353797a7a295f0936b0925774ab590eb064bf13e Mon Sep 17 00:00:00 2001
From: Oliver Hummel <oliver@192.168.127.203>
Date: Tue, 19 Dec 2023 17:06:45 +0100
Subject: [PATCH] =?UTF-8?q?Einfache=20Persistenz=20hinzugef=C3=BCgt.?=
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---
 Banksystem/src/bank/Bank.java      | 37 +++++++++++++++++++++++++++++-
 Banksystem/src/bank/BankUI.java    |  4 +++-
 Banksystem/src/bank/Bankkonto.java |  3 ++-
 3 files changed, 41 insertions(+), 3 deletions(-)

diff --git a/Banksystem/src/bank/Bank.java b/Banksystem/src/bank/Bank.java
index ae0ae92..e08b1f8 100644
--- a/Banksystem/src/bank/Bank.java
+++ b/Banksystem/src/bank/Bank.java
@@ -1,8 +1,15 @@
 package bank;
 
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.ObjectInputStream;
+import java.io.ObjectOutputStream;
+import java.io.Serializable;
 import java.util.ArrayList;
 
-public class Bank {
+public class Bank implements Serializable {
 	private String name;
 	private ArrayList<Bankkonto> kontenliste;
 
@@ -16,6 +23,8 @@ public class Bank {
 		kontenliste.add(bk);
 		
 		// Speichern Methode 2: geänderte Daten speichern
+		saveBankData();		// bzw. der Einfachheit halber: alle Daten ;-)
+		
 		return bk.getKontonummer();
 	}
 	
@@ -43,4 +52,30 @@ public class Bank {
 		return null;
 	}
 
+	// Die folgenden Persistenz-Methoden würde man in der Praxis in eine eigene
+	// Klasse auslagern.
+	private void saveBankData() {
+		ObjectOutputStream oos;
+		try {
+			oos = new ObjectOutputStream(new FileOutputStream("BankData.ser"));
+			oos.writeObject(this);
+			oos.close();
+		} catch (FileNotFoundException e) {
+			e.printStackTrace();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+	
+	public static Bank loadBankData() {
+		try {
+			ObjectInputStream ois = new ObjectInputStream(new FileInputStream("BankData.ser"));
+			return (Bank) ois.readObject();
+		} catch (IOException | ClassNotFoundException e) {
+			System.err.println("Keine Daten gespeichert, initialisiere alle Daten neu.");
+		}
+		
+		return new Bank("Spaßkasse");
+	}
+	
 }
diff --git a/Banksystem/src/bank/BankUI.java b/Banksystem/src/bank/BankUI.java
index 52afb62..d8eaeed 100644
--- a/Banksystem/src/bank/BankUI.java
+++ b/Banksystem/src/bank/BankUI.java
@@ -3,10 +3,12 @@ package bank;
 import java.util.Scanner;
 
 public class BankUI {
-	private static Bank bank = new Bank("Spaßkasse");
+	private static Bank bank;
 	private static Scanner kb = new Scanner(System.in);
 
 	public static void main(String[] args) {
+		bank = Bank.loadBankData();
+		
 		willkommen();
 		hauptmenü();
 	}
diff --git a/Banksystem/src/bank/Bankkonto.java b/Banksystem/src/bank/Bankkonto.java
index 55f7231..978c330 100644
--- a/Banksystem/src/bank/Bankkonto.java
+++ b/Banksystem/src/bank/Bankkonto.java
@@ -1,8 +1,9 @@
 package bank;
 
+import java.io.Serializable;
 import java.util.ArrayList;
 
-public class Bankkonto {
+public class Bankkonto implements Serializable {
 	// sog. Geheimnisprinzip, Attribute bleiben
 	// privat, Zugriff erfolgt nur über Methoden
 	private String name;