Remove rows from JTable

Question

I want to remove some rows from a JTable. Please help me.

Answer 1

A JTable normally forms the View part of an MVC implementation. You'll want to remove rows from your model. The JTable, which should be listening for these changes, will update to reflect this removal. Hence you won't find removeRow() or similar as a method on JTable.

Answer 2

Look at the DefaultTableModel for a simple model that you can use:

http://java.sun.com/javase/6/docs/api/javax/swing/table/DefaultTableModel.html

This extends the AbstractTableModel, but should be sufficient for basic purposes. You can always extend AbstractTableModel and create your own. Make sure you set it on the JTable as well.

http://java.sun.com/javase/6/docs/api/javax/swing/table/AbstractTableModel.html

Look at the basic Sun tutorial for more information on using the JTable with the table model:

http://java.sun.com/docs/books/tutorial/uiswing/components/table.html#data

Answer 3

In order to remove a row from a JTable, you need to remove the target row from the underlying TableModel. If, for instance, your TableModel is an instance of DefaultTableModel, you can remove a row by doing the following:

((DefaultTableModel)myJTable.getModel()).removeRow(rowToRemove);

Answer 4

The correct way to apply a filter to a JTable is through the RowFilter interface added to a TableRowSorter. Using this interface, the view of a model can be changed without changing the underlying model. This strategy preserves the Model-View-Controller paradigm, whereas removing the rows you wish hidden from the model itself breaks the paradigm by confusing your separation of concerns.

Answer 5

If you need a simple working solution, try using DefaultTableModel.

If you have created your own table model, that extends AbstractTableModel, then you should also implement removeRow() method. The exact implementation depends on the underlying structure, that you have used to store data.

For example, if you have used Vector, then it may be something like this:

public class SimpleTableModel extends AbstractTableModel {
    private Vector<String> columnNames = new Vector<String>();
    // Each value in the vector is a row; String[] - row data;
    private Vector<String[]> data = new Vector<String[]>();

    ...

    public String getValueAt(int row, int col) {
        return data.get(row)[col];
    }

    ...

    public void removeRow(int row) {
        data.removeElementAt(row);
    }
}

If you have used List, then it would be very much alike:

// Each item in the list is a row; String[] - row data;
List<String[]> arr = new ArrayList<String[]>();

public void removeRow(int row) {
    data.remove(row);
}

HashMap:

//Integer - row number; String[] - row data;
HashMap<Integer, String[]> data = new HashMap<Integer, String[]>();

public void removeRow(Integer row) {
    data.remove(row);
}

And if you are using arrays like this one

String[][] data = { { "a", "b" }, { "c", "d" } };

then you're out of luck, because there is no way to dynamically remove elements from arrays. You may try to use arrays by storing separately some flags notifying which rows are deleted and which are not, or by some other devious way, but I would advise against it... That would introduce unnecessary complexity, and would in fact just be solving a problem by creating another. That's a sure-fire way to end up here. Try one of the above ways to store your table data instead.

For better understanding of how this works, and what to do to make your own model work properly, I strongly advise you to refer to Java Tutorial, DefaultTableModel API and it's source code.