Develop Reference

Recreate Jtable or remove all rows and add new rows?

I have a JTable and a DefaultTableModel, I want to delete all the rows of JTable every 3 secondes and add new rows to the JTable. Considering the performance, What's the best choice to do that, recreate Jtable or remove all rows and add rows?

What's the best choice to do that, renew Jtable or remove all rows and addrows?
If you recreate the JTable, all the renderers and editors will be recreated for the table.
If you change the TableModel, then the table will need to recreate the TableColumnModel, and all the TableColumns based on the new TableModel.
There will be many more objects that need to be created to support the JTable/TableModel relationship.
Removing rows and adding rows, will just cause the table to repaint the new data using all the current renderers. I would say this is more efficient. And instead of adding rows one at a time, you should add all the rows at once

You can create a tablemodel that digs into your data object. As soon as you change the underlying data object, you call fireTableDataChanged().
From the JavaDoc for AbstractTableModel#fireTableDataChanged():
Notifies all listeners that all cell values in the table's rows may have changed. The number of rows may also have changed and the JTable should redraw the table from scratch. The structure of the table (as in the order of the columns) is assumed to be the same.

java swing jtable - display row index for each row

I'm working on a java desktop application and I have a Swing JTable for displaying data. I need to have a column for displaying row index for each row in the table. I don't want to add index in the grid data. Here is the way that I'm using to fill my table:
private DefaultTableModel defaultTableModel = new DefaultTableModel();
defaultTableModel.setDataVector(dataArray, headerArray);
jTable.setModel(defaultTableModel);

JTable displays what the TableModel tells it to display. Instead, extend AbstractTableModel. In your implementation of getValueAt(), return the row number for column zero and return the appropriate element of dataArray otherwise. Related examples may be found here and here.

You can add a row header to the scroll pane to display numbers for each row in the table.
Any component can be added to the row header. So one solution is to add a second (custom) JTable that just displays row numbers with a custom renderer so that the number look like the column headers.
Check out Row Table Number for an example of this approach.

Selected Row in JTable along with Sorting

I have a very odd issue with JTable.
I put data in JTable from DB. When user double clicks on any cell, it copies the cell contents of the first column of the row where user double clicked. So far, it works perfect.
The problem arises when the user sorts the JTable by clicking on the header. when the table has been sorted and now when the user double clicks on any row, it doesn't what is currently stored on that row's first column. It copies what was originally stored on the first column of that row when the JTable was not sorted.
Any ideas?

Problem:
The problem here is that you are getting the initial rows indexes in the JTable TableModel, and not the relevants row indexes shown in the table view.
Solution:
You can map the shown indexes of a sorted jTable with their relevants ones in the dataModel using convertRowIndexToModel(index) method which takes in input the row index in the view and returns the index of the corresponding row in the model.
Let's say that you have the following jTable:
TableModel myModel = createMyTableModel();
JTable table = new JTable(myModel);
table.setRowSorter(new TableRowSorter(myModel));
And then loop throught model indexes and use this method with each index to get its corresponding one in the TableModel:
table.getRowSorter().convertRowIndexToModel(0); // index 0 here

As suggested in How to Use Tables: Sorting and Filtering, "When using a sorter, always remember to translate cell coordinates." Most likely, you have neglected this in your event handler.

Try Sorting your JTable TableModel data too. Jtable -> TableModel is the one which hold the actual data. JTable is just a view.

Updating JTable row dynamically after the deletion successive rows

I have a JTable and I am inserting rows to that JTable dynamically.
After some user intervention, a new row will be inserted .Then I will call a function with parameter as selected row number and inside that function, I have some code which will update the same row accordingly. Each row insertion and row value update code will run in a separate thread.
public void updateRow(int row,JTable myTable)
{
String text = "";
//After lot of processing, setting the table cell value at the 'row' on the 4th column
myTable.setValueAt(text, row, 4);
}
The issue I am facing is as follows,
If the user deleting any row, then row's position will change and at that time if the function updateRow() trying to update some other row, then it will fail because of change of row count.
Lets say I have 3 row at a time and each row's updateRow is in progress.
updateRow(0,userTable);//For the 1st row
updateRow(1,userTable);//For the 2nd row
updateRow(2,userTable);//For the 3rd row
and assume 2nd row's updateRow() is completed. This will cause issue in updateRow() function of 3rd row. Because, it has the row value as '2' . Since the 3rd row got deleted, there is no 3rd row and which in turn cause the following code to fail
myTable.setValueAt(text, row, 4);//Currently, row has the value as '2'
Can anyone suggest me how can I keep track of the row update with row values accordingly, even if the row's position got changed dynamically ?
Thanks in advance.

Instead of relying on the view's row number, operate on the model directly, as suggested in a comment by #mKorbel; if you alter the model, the view will follow. As discussed here, "JTable provides methods that convert from model coordinates to view coordinates — convertColumnIndexToView and convertRowIndexToView — and that convert from view coordinates to model coordinates — convertColumnIndexToModel and convertRowIndexToModel.

how to add row values to jtable in java swing?

I have a jcombo box which has some items like "schoolbooks","collegebooks","historybooks".and i have dynamic ArrayList object of corresponding books...When i click the combo box item "schoolbooks" or "historybooks" ,it should display the contents in JTable from the arraylist.while every action performing,the JTable has to display the contents of the corresponding item of 'schoolbooks' or 'historybooks' .it should not append new rows when every action is performing ...i have used default table model in this.but when i add 3 or 4 rows using default table model,its appending the row with previous here..if i use removeRow(i) in for loop ,its removing 1 row or 2 rows only...Its not removing previous all rows suppose if i have 7 rows ..i am not able to solve this..please if anyone know this,please help...

You might want to review How to Use Tables as a guide to preparing your sscce. As you are using DefaultTableModel, you'll need to show how you construct the Object[] passed to addRow() and how you calculate the index passed to removeRow().

if i use removeRow(i) in for loop ,its removing 1 row or 2 rows only...Its not removing previous all rows suppose if i have 7 rows
When you remove multiple rows you need to remove the row from the end of the table down to 0:
for (int i = table.getRowCount() - 1; i > 0; i--)
{
// add logic here
}