Calculating the sum of diffrent columns in TableView - tableview

Question

I have a Table Witch look like the below table
TableVeiw<Transaction>
---------------------------------------------------------------------
| id | Transaction date | Name | type | Debit Amount | Credit Amount|
|---------------------------------------------------------------------|
| 1 | 21/02/2016 |Invoice|Credit | | 12000 |
|---------------------------------------------------------------------|
| 2 | 21/02/2016 |Payment|Debit | 20000 | |
|---------------------------------------------------------------------|
| Total Debit | Total Credit |
-----------------------------
The data in Debit amount and Credit amount come from one property of Transaction Object the code snnipet of how to populate those columns is below:
tcCreditAmmout.setCellValueFactory(cellData -> {
Transaction transaction = cellData.getValue() ;
BigDecimal value = null;
if(transaction.getKindOfTransaction() == KindOfTransaction.CREDIT){
value = transaction.getAmountOfTransaction();
}
return new ReadOnlyObjectWrapper<BigDecimal>(value);
});
tcDebitAmmout.setCellValueFactory(cellData -> {
Transaction transaction = cellData.getValue() ;
BigDecimal value = null;
if(transaction.getKindOfTransaction() == KindOfTransaction.DEBIT){
value = transaction.getAmountOfTransaction();
}
return new ReadOnlyObjectWrapper<BigDecimal>(value);
});
I need to calculate the total of :Total Debit(See the above table) and Total Credit (See the above table) every time the TableView item changes via Javafx Bindings, but i have no idea how to acheive this.
Note: Total Debit and Total Credit are Labels ,

Answer 1

Assuming you have
TableView<Transaction> table = ... ;
Label totalDebit = ... ;
Label totalCredit = ... ;
then you just need:
totalDebit.textProperty().bind(Bindings.createObjectBinding(() ->
table.getItems().stream()
.filter(transaction -> transaction.getKindOfTransaction() == KindOfTransaction.DEBIT)
.map(Transaction::getAmountOfTransaction)
.reduce(BigDecimal.ZERO, BigDecimal::add),
table.getItems())
.asString("%.3f"));
and of course
totalCredit.textProperty().bind(Bindings.createObjectBinding(() ->
table.getItems().stream()
.filter(transaction -> transaction.getKindOfTransaction() == KindOfTransaction.CREDIT)
.map(Transaction::getAmountOfTransaction)
.reduce(BigDecimal.ZERO, BigDecimal::add),
table.getItems())
.asString("%.3f"));
If getAmountOfTransaction might change while the transaction is part of the table, then your table's items list must be constructed with an extractor.