Las cajas pueden ser Empty y tener id = 0

Se debe comprobar para ello. si no se hara una query con un id invalido.

src/danielcortes/xyz/models/calculo_fondo/SQLiteCalculoFondoDAO.java

@@ -65,6 +65,11 @@ public class SQLiteCalculoFondoDAO extends CalculoFondoDAO {
   @Override
   public List<CalculoFondo> findByCaja(Caja caja) {
     List<CalculoFondo> calculoFondoList = new ArrayList<>();
+
+    if(Caja.EMPTY == caja){
+      return calculoFondoList;
+    }
+
     String query = "select * from calculo_fondo where caja_id = ?";
     try (Connection conn = connectionHolder.getConnection()) {
       try (PreparedStatement ps = conn.prepareStatement(query)) {
@@ -176,6 +181,11 @@ public class SQLiteCalculoFondoDAO extends CalculoFondoDAO {
   @Override
   public int getTotalCalculoFondo(Caja caja) {
     int sum = 0;
+
+    if(Caja.EMPTY == caja){
+      return sum;
+    }
+
     String query = "select sum(valor) from calculo_fondo where caja_id = ?";
     try (Connection conn = connectionHolder.getConnection()) {
       try (PreparedStatement ps = conn.prepareStatement(query)) {