How to change JTable header height?

Question

Title explains the question. How can I easily do that?

Answer 1

import java.awt.*;
import java.awt.event.*;
import java.util.List;
import java.util.Arrays;
import javax.swing.*;
import javax.swing.table.*;

public class TableHeaderHeightTest {
  private static int HEADER_HEIGHT = 32;
  private JTable makeTable() {
    JTable table = new JTable(new DefaultTableModel(2, 20));
    table.setAutoResizeMode(JTable.AUTO_RESIZE_OFF);
    return table;
  }
  public JComponent makeUI() {
    JPanel p = new JPanel(new GridLayout(2,1));

    JTable table1 = makeTable();
    //Bad: >>>>
    JTableHeader header = table1.getTableHeader();
    //Dimension d = header.getPreferredSize();
    //d.height = HEADER_HEIGHT;
    //header.setPreferredSize(d); //addColumn case test
    header.setPreferredSize(new Dimension(100, HEADER_HEIGHT));
    p.add(makeTitledPanel("Bad: JTableHeader#setPreferredSize(...)", new JScrollPane(table1)));
    //<<<<

    JTable table2 = makeTable();
    JScrollPane scroll = new JScrollPane(table2);
    scroll.setColumnHeader(new JViewport() {
      @Override public Dimension getPreferredSize() {
        Dimension d = super.getPreferredSize();
        d.height = HEADER_HEIGHT;
        return d;
      }
    });
//         //or
//         table2.setTableHeader(new JTableHeader(table2.getColumnModel()) {
//             @Override public Dimension getPreferredSize() {
//                 Dimension d = super.getPreferredSize();
//                 d.height = HEADER_HEIGHT;
//                 return d;
//             }
//         });
    p.add(makeTitledPanel("Override getPreferredSize()", scroll));

    final List<JTable> list = Arrays.asList(table1, table2);

    JPanel panel = new JPanel(new BorderLayout());
    panel.add(p);
    panel.add(new JButton(new AbstractAction("addColumn") {
      @Override public void actionPerformed(ActionEvent e) {
        for(JTable t: list) {
          t.getColumnModel().addColumn(new TableColumn());
          JTableHeader h = t.getTableHeader();
          Dimension d = h.getPreferredSize();
          System.out.println(d);
        }
      }
    }), BorderLayout.SOUTH);
    panel.setBorder(BorderFactory.createEmptyBorder(5,5,5,5));
    return panel;
  }
  private static JComponent makeTitledPanel(String title, JComponent c) {
    JPanel p = new JPanel(new BorderLayout());
    p.add(c);
    p.setBorder(BorderFactory.createTitledBorder(title));
    return p;
  }
  public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
      @Override public void run() {
        createAndShowGUI();
      }
    });
  }
  public static void createAndShowGUI() {
    JFrame f = new JFrame();
    f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
    f.getContentPane().add(new TableHeaderHeightTest().makeUI());
    f.setSize(320, 320);
    f.setLocationRelativeTo(null);
    f.setVisible(true);
  }
}

Answer 2

try this.....

if jtable attached to scrollpane 
  then 
table.getTableHeader().setPreferredSize(
     new Dimension(scrollpane.getwidth(),height)
);

else
  table.getTableHeader().setPreferredSize(
     new Dimension(width,height)
);

Answer 3

Font bigFont = new Font("sansserif", Font.PLAIN, 24); // or whatever
myTable.getTableHeader().setFont(bigFont);

This is a simple way to increase the preferredSize of the TableHeader. It will increase the height of the header, but if your column names are too long then they might not fit widthwise.