Optimized Exception handling for De-/Serialization in PrivateBank.java

src/main/java/bank/PrivateBank.java

@@ -367,7 +367,7 @@ public class PrivateBank implements Bank, JsonSerializer<Transaction>, JsonDeser
      *
      * @throws IOException if an error occurs while deserializing
      */
-    public void readAccounts() throws IOException, java.io.IOException, AccountAlreadyExistsException, TransactionAlreadyExistException, TransactionAttributeException {
+    public void readAccounts() throws IOException, AccountAlreadyExistsException, TransactionAlreadyExistException, TransactionAttributeException {
         /*
         1. JSONs einlesen
         2. for each Transaction
@@ -375,23 +375,30 @@ public class PrivateBank implements Bank, JsonSerializer<Transaction>, JsonDeser
             2. Objekte in einer Liste zusammenführen
         3. Konto mit einer Liste von Transaktionen erzeugen
          */
-        List<Transaction> transactions = new ArrayList<>();
-
         File directory = new File(directoryName);
         File[] files = directory.listFiles();
 
         if (files != null) {
             // jedes file ist ein Konto
             for (File file : files) {
+                List<Transaction> transactions;
                 String accountName = file.getName().substring(0, file.getName().lastIndexOf("."));
+                String jsonContent;
+
+                try {
+                    jsonContent = Files.readString(Paths.get(directoryName + "/" + file.getName()));
+                } catch (java.io.IOException e) {
+                    System.out.println("Zum Account: " + accountName + " konnte die Datei nicht geöffnet werden");
+                    continue;
+                }
 
-                String jsonContent = Files.readString(Paths.get(directoryName + "/" + file.getName()));
                 JsonElement accountData = JsonParser.parseString(jsonContent);
 
-                for (JsonElement account : accountData.getAsJsonArray()) {
+                try{
-                    JsonObject accountObject = account.getAsJsonObject();
+                    transactions = readAccountHelper(accountData, accountName);
-                    Transaction t = deserialize(accountObject, null, null);
+                } catch (IOException e){
-                    transactions.add(t);
+                    System.out.println(e);
+                    continue;
                 }
 
                 createAccount(accountName, transactions);
@@ -399,6 +406,21 @@ public class PrivateBank implements Bank, JsonSerializer<Transaction>, JsonDeser
         }
     }
 
+    private List<Transaction> readAccountHelper(JsonElement accountData, String accountName) throws IOException {
+        List<Transaction> transactions = new ArrayList<>();
+        for (JsonElement account : accountData.getAsJsonArray()) {
+            JsonObject accountObject = account.getAsJsonObject();
+            Transaction t;
+            try{
+                t = deserialize(accountObject, null, null);
+            } catch (JsonParseException e){
+                throw new IOException("Fehler beim Laden des Accounts: " + accountName);
+            }
+            transactions.add(t);
+        }
+        return transactions;
+    }
+
     /**
      * Export Account to JSON
      *
@@ -415,7 +437,11 @@ public class PrivateBank implements Bank, JsonSerializer<Transaction>, JsonDeser
         List<Transaction> transactions = this.accountsToTransactions.get(account);
 
         for (Transaction transaction : transactions)
-            accountData.add(serialize(transaction, null, null));
+            try{
+                accountData.add(serialize(transaction, null, null));
+            } catch (JsonParseException e){
+                throw new IOException("Fehler beim Speichern des Accounts: " + account);
+            }
 
         Gson gson = new GsonBuilder().setPrettyPrinting().create();
         String filename = directoryName + "/" + account + ".json";
@@ -458,8 +484,9 @@ public class PrivateBank implements Bank, JsonSerializer<Transaction>, JsonDeser
             case "Payment":
                 return new Payment(date, amount, description, transactionInstance.get("incomingInterest").getAsDouble(), transactionInstance.get("outgoingInterest").getAsDouble());
 
+            default:
+                throw new JsonParseException("Unknown transaction type: " + transactionType);
         }
-        return null;
     }
 
     /**
@@ -482,7 +509,8 @@ public class PrivateBank implements Bank, JsonSerializer<Transaction>, JsonDeser
 
         else if (transaction instanceof Payment)
             rootObject.addProperty("CLASSNAME", "Payment");
-
+        else
+            throw new JsonParseException("Unknown transaction type: " + transaction.getClass().getName());
 
         JsonObject jsonObject = new JsonObject();
 

src/main/java/bank/exceptions/IOException.java

@@ -1,7 +1,7 @@
 package bank.exceptions;
 
 public class IOException extends Exception {
-    public IOException() {
+    public IOException(String message) {
-        super("Fehler in der De-/ Serialisierung der Daten");
+        super("Fehler in der De-/ Serialisierung der Daten. " + message);
     }
 }