added error loggings and minor tweaks

src/main/java/iotaFlashWrapper/Helpers.java

@@ -38,7 +38,6 @@ public class Helpers {
      * @param transfers
      * @param toUse Transaction helper object
      * @param user
-     * @param shouldClose
      * @return
      */
     public static ArrayList<Bundle> createTransaction(ArrayList<Transfer> transfers, CreateTransactionHelperObject toUse, UserObject user) {
@@ -55,6 +54,11 @@ public class Helpers {
                 user.getUserIndex(),
                 transfers
         );
+
+        if (newTransfers == null) {
+            return new ArrayList<>();
+        }
+
         // Compose the transaction. This may also add some management transactions (moving remainder tokens.)
         bundles = IotaFlashBridge.compose(
                 flash.getBalance(),
@@ -302,7 +306,6 @@ public class Helpers {
         return attachedBundles;
     }
 
-
     /**
      * creates a new iota instace with the defined url and mode (testnet or not)
      * if api instance available the just return it

src/main/java/iotaFlashWrapper/IotaFlashBridge.java

@@ -126,8 +126,14 @@ public class IotaFlashBridge {
         params.add(V8Converter.transferListToV8Array(engine, transfers));
 
         // Call js function.
+        try {
             V8Array ret = transfer.executeArrayFunction("prepare", V8ObjectUtils.toV8Array(engine, params));
             return V8Converter.transferListFromV8Array(ret);
+        } catch (V8ScriptExecutionException exception) {
+
+            return null;
+        }
+
     }
 
 

src/main/java/iotaFlashWrapper/Main.java

@@ -144,7 +144,7 @@ public class Main {
         ArrayList<Bundle> confirmedTransfers;
 
         // Try to make 10 transfers.
-        for (int i = 0; i < 4; i++) {
+        for (int i = 0; i < 2; i++) {
 
             // Create transaction helper and check if we need to add nodes
             CreateTransactionHelperObject helper = Helpers.getTransactionHelper(oneFlash.getFlash().getRoot());
@@ -252,13 +252,7 @@ public class Main {
         Helpers.applyTransfers(signedBundlesOne, oneFlash);
         Helpers.applyTransfers(signedBundlesTwo, twoFlash);
 
-        System.out.println("[INFO] Channel closed!");
+        List<Bundle> attachedBundles = Helpers.POWClosedBundle(signedBundlesOne, 4, 13);
-
-        // TODO: find why there is a internal bundle at the start. But only the last one should be used.
-        List<Bundle> closeBundles = new ArrayList<>();
-        closeBundles.add(signedBundlesOne.get(signedBundlesOne.size() - 1));
-
-        List<Bundle> attachedBundles = Helpers.POWClosedBundle(signedBundlesOne, 5, 10);
 
         System.out.println("[INFO] Attached bundles" + attachedBundles.toString());
     }

src/main/java/iotaFlashWrapper/Model/FlashLibJSException.java

@@ -0,0 +1,21 @@
+package iotaFlashWrapper.Model;
+
+public class FlashLibJSException extends Exception {
+
+    public enum FlashLibJSExceptionType {
+        INSUFFICIENT_FUNDS, UNKNOWN
+    }
+
+
+    private FlashLibJSExceptionType type = FlashLibJSExceptionType.UNKNOWN;
+
+    public FlashLibJSException(String string) {
+        if (string.contains(FlashLibJSExceptionType.INSUFFICIENT_FUNDS.name())) {
+            this.type = FlashLibJSExceptionType.INSUFFICIENT_FUNDS;
+        }
+    }
+
+    public FlashLibJSExceptionType getType() {
+        return type;
+    }
+}