Suppose I have a JTable with rows like this:
(2, 1)
(1, 3)
(1, 5)
(3, 1)
(2, 3)
(2, 4)
I want to sort JTable so that rows that have 1 in the first or second column are at the top, and the rest of the rows may have an arbitrary order:
(1, 3)
(1, 5)
(2, 1)
(3, 1)
(2, 3)
(2, 4)
Is there a way to do this in a table with TableRowSorter?
UPD: I want to sort the table programmatically, not through UI (clicking on the column headers)
You can define a Comparator for the first column using setComparator method. Then, in your compare method in the Comparator, return -1 if the first argument is 1, 1 if second argument is 1 and 0 otherwise.
from code
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
public class TableBoolean extends JFrame {
private final static String LETTERS = "ABCDEFGHIJKLMNOPQRSTUVWXYZ";
private static final long serialVersionUID = 1L;
private JTable table;
private DefaultTableModel model;
public TableBoolean() {
Object[][] data = {{"A", new Boolean(false), 2, 1}, {"B", new Boolean(true), 1, 3},
{"A", new Boolean(false), 1, 5}, {"B", new Boolean(true), 3, 1},
{"A", new Boolean(false), 2, 3}, {"B", new Boolean(true), 2, 4},
{"A", new Boolean(false), 5, 2}, {"B", new Boolean(true), 7, 1}};
String[] columnNames = {"String", "Boolean", "Integer", "Integer"};
model = new DefaultTableModel(data, columnNames) {
private static final long serialVersionUID = 1L;
@Override
public Class getColumnClass(int column) {
return getValueAt(0, column).getClass();
}
@Override
public boolean isCellEditable(int row, int column) {
return true;
}
};
table = new JTable(model);
TableRowSorter<TableModel> sorter = new TableRowSorter<TableModel>(table.getModel());
table.setRowSorter(sorter);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane(table);
add(scrollPane);
/*JButton button = new JButton("Add Row");
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
Object[] newRow = new Object[2];
int row = table.getRowCount() + 1;
newRow[0] = LETTERS.substring(row - 1, row);
newRow[1] = (row % 2 == 0) ? new Boolean(true) : new Boolean(false);
model.addRow(newRow);
}
});
add(button, BorderLayout.SOUTH);*/
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
@Override
public void run() {
TableBoolean frame = new TableBoolean();
frame.setDefaultCloseOperation(EXIT_ON_CLOSE);
frame.pack();
frame.setVisible(true);
}
});
}
}
I figured a way to do it w/o using TableRowSorter: you can presort data in the TableModel, then fire an event to let the table know that the data changed. Here is the pseudocode:
Set up the table:
AbstractTableModel model = new MyModel();
JTable table = new JTable(model);
Implement MyModel:
public class MyModel implements AbstractTableModel {
private ArrayList<Integer> data;
...
// implement interface methods
...
public void sortToTop(int a) {
// float all rows w/ a in the first column to the top
Collections.sort(data, new Comparator<Integer>() {
public int compare(int o1, int o2) {
if (o1 == a) return -1;
if (o2 == a) return 1;
return o1.compareTo(o2);
}
});
// find how many rows at the top have a in the first row
int startIndex = 0;
boolean notFound = true;
while (startIndex < data.size() && notFound) {
if (data.get(startIndex) == a)
startIndex++;
else
notFound = false;
}
int endIndex = data.size();
// get a sublist w/o these first rows
List<Integer> sublist = data.subList(startIndex, endIndex);
// sort sublist on the second column floating a to the top
Collections.sort(sublist, new Comparator<Integer>() {
public int compare(int o1, int o2) {
if (o1 == a) return -1;
if (o2 == a) return 1;
return o1.compareTo(o2);
}
});
this.fireTableDataChanged();
}
}
The easiest way to do this in my opinion is to first call sort on the second column, which will result in something like this:
(3, 1)
(2, 1)
(1, 3)
(2, 3)
(2, 4)
(1, 5)
but this is not yet complete. If we then call sort on the first column, then we will have:
(1, 3)
(1, 5)
(2, 1)
(2, 3)
(2, 4)
(3, 1)
This is by far the easiest way to do it.
