Changing the margins between JTable grid lines and cell data

You can do so with the JTable method setIntercellSpacing.

Main.java:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
 
public class Main extends JFrame 
{
   public Main() {
      super("Table example, Wines from Bordeaux");
 
      Object[][] tabledata = {
            { "Chateau Meyney, St. Estephe", 	   new Integer(1994), "$18.75"},
            { "Chateau Montrose, St. Estephe", 	   new Integer(1975), "$54.25" },
            { "Chateau Gloria, St. Julien", 	   new Integer(1993), "$22.99" },
            { "Chateau Beychevelle, St. Julien",   new Integer(1970), "$61.63" },
            { "Chateau La Tour de Mons, Margeaux", new Integer(1975), "$57.03" },
            { "Chateau Brane-Cantenac, Margeaux",  new Integer(1978), "$49.92" },
      };
 
      String columnheaders[] = { "Wine", "Vintage", "Price" };
 
      JTable table = new JTable(tabledata, columnheaders);
      table.setPreferredScrollableViewportSize(new Dimension(500, 70));
      JScrollPane scrollPane = new JScrollPane(table);
 
      table.setIntercellSpacing(new Dimension (10,20));
  
      getContentPane().add(scrollPane);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
 
      pack();
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.show();
   }
}

Adding a background image to a JTree

Main.java:

import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.awt.*;
import java.net.*;
import java.awt.event.*;
 
public class Main extends JFrame
{
   public Main() {
      DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
      for (int i=0; i<10; i++) {
         DefaultMutableTreeNode child = new DefaultMutableTreeNode("Child " + (i+1));
         root.add(child);
      }
      JTree tree = new JTree(root) {
         ImageIcon icon = new ImageIcon("mong.jpg");
 
         public void paint( Graphics g ) 
         { 
            // tile it
            Dimension d = this.getSize(); 
            for(int i=0; i<d.width; i+=icon.getIconWidth()) { 
               for(int j=0; j<d.height; j+=icon.getIconHeight()) { 
                  g.drawImage(icon.getImage(), i, j, null, null); 
               }
            }
 
            super.paint(g); 
         } 
      }; 
 
      tree.setOpaque( false );
  
 
      DefaultTreeCellRenderer cr = new DefaultTreeCellRenderer();
      cr.setOpaque(false);
      cr.setBackground(new Color(0, 0, 0, 0));  
      cr.setBackgroundNonSelectionColor(null);
      tree.setCellRenderer(cr);
 
      getContentPane().add(new JScrollPane(tree));
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.setSize(400, 400);
      main.setVisible(true);
   }
}

Image used: http://www.esus.com/images/mong.jpg

Disabling selection in my JTable

Look at the three lines of code in this working program to find out how to disallow any selection.

Main.java:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
 
public class Main extends JFrame 
{
   public Main() {
      super("Table example, Wines from Bordeaux");
 
      Object[][] tabledata = {
            { "Chateau Meyney, St. Estephe", 	   new Integer(1994), "$18.75"},
            { "Chateau Montrose, St. Estephe", 	   new Integer(1975), "$54.25" },
            { "Chateau Gloria, St. Julien", 	   new Integer(1993), "$22.99" },
            { "Chateau Beychevelle, St. Julien",   new Integer(1970), "$61.63" },
            { "Chateau La Tour de Mons, Margeaux", new Integer(1975), "$57.03" },
            { "Chateau Brane-Cantenac, Margeaux",  new Integer(1978), "$49.92" },
      };
 
      String columnheaders[] = { "Wine", "Vintage", "Price" };
 
      JTable table = new JTable(tabledata, columnheaders);
      table.setPreferredScrollableViewportSize(new Dimension(500, 70));
      JScrollPane scrollPane = new JScrollPane(table);
 
      getContentPane().add(scrollPane);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
 
      // disable selection
      table.setRowSelectionAllowed(false);
      table.setColumnSelectionAllowed(false);
      table.setCellSelectionEnabled(false);
 
      pack();
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.show();
   }
}

Have two JTrees vertically aligned in a JScrollPane

Main.java:

import javax.swing.*;
import javax.swing.tree.*;
import javax.swing.event.*;
import java.awt.*;
import java.net.*;
import java.awt.event.*;
 
public class Main extends JFrame
{
   public Main() {
      DefaultMutableTreeNode root = createNodes();
      JTree tree1 = new JTree(root);
      JTree tree2 = new JTree(root);
 
      tree1.addTreeSelectionListener(new TreeSelectionListener() {
         public void valueChanged(TreeSelectionEvent e) {         
            TreePath path = e.getPath();
            System.out.println(path.getLastPathComponent());     
         }
      });
 
      tree2.addTreeSelectionListener(new TreeSelectionListener() {
         public void valueChanged(TreeSelectionEvent e) {         
            TreePath path = e.getPath();
            System.out.println(path.getLastPathComponent());     
         }
      });
  
      Box box = Box.createVerticalBox();
      box.add(tree1);
      box.add(tree2);
 
      // bugparade #4833645
      tree1.setMinimumSize(tree1.getPreferredSize());
      tree1.setAlignmentX(0);
      tree2.setMinimumSize(tree2.getPreferredSize());
      tree2.setAlignmentX(0);
 
      getContentPane().setLayout(new BorderLayout());
     
      JScrollPane sp = new JScrollPane(box);
      sp.getViewport().setBackground(Color.white);
 
      getContentPane().add(BorderLayout.NORTH, sp);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
   }
  
   public static DefaultMutableTreeNode createNodes() {
      DefaultMutableTreeNode root = new DefaultMutableTreeNode("Java");
      
      DefaultMutableTreeNode j2se = new DefaultMutableTreeNode("J2SE");
      DefaultMutableTreeNode j2ee = new DefaultMutableTreeNode("J2EE");
      DefaultMutableTreeNode j2me = new DefaultMutableTreeNode("J2ME");
 
      j2se.add(new DefaultMutableTreeNode("http://java.sun.com/j2se/"));
      j2ee.add(new DefaultMutableTreeNode("http://java.sun.com/j2ee/"));
      j2me.add(new DefaultMutableTreeNode("http://java.sun.com/j2me/"));
 
      root.add(j2se);
      root.add(j2ee);
      root.add(j2me);
 
      return root;
   }
 
   public static void main(String []args) {
      Main main = new Main();
      main.setSize(400, 400);
      main.setVisible(true);
   }
}

Scrolling a JScrollPane to the top programmatically

Call the method scrollRectToVisible of the component that is added to the JScrollPane container as shown in following example:

Main.java:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
 
public class Main extends JFrame
{
   public Main() throws Exception {
      getContentPane().setLayout(new BorderLayout());
 
      final JPanel panel = createPanel(); 
      final JScrollPane scrollpane = new JScrollPane(panel);
 
      JButton button = new JButton("Scroll to top!");
      button.addActionListener(new ActionListener() {
         public void actionPerformed(ActionEvent ae) {
            panel.scrollRectToVisible(
              new Rectangle(0, 0, 1, 1));
         }
      });
 
      getContentPane().add(BorderLayout.NORTH, button);
      getContentPane().add(BorderLayout.CENTER, scrollpane);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0);
         }
      });
   }
 
   public static JPanel createPanel() throws Exception {
      JPanel panel = new JPanel();
      panel.setLayout(new GridLayout(50, 20, 10, 10));
 
      for (int i=0; i<50; i++) {
         for (int j=0; j<20; j++) {
            JLabel label = new JLabel("label " + i + ", " + j);
            panel.add(label);    
         }
      }
 
      return panel;
   }
 
   public static void main(String [] args) throws Exception  {
      Main main = new Main();
      main.setSize(600, 600);
      main.setVisible(true);
   } 
} 

Creating a JInternalFrame without a title bar

Try this:

   javax.swing.plaf.InternalFrameUI ui = frame.getUI();
   ((javax.swing.plaf.basic.BasicInternalFrameUI)ui).setNorthPane(null);

Main.java:

import java.awt.image.*;
import java.awt.event.*;
import java.applet.*;
import javax.swing.*;
import java.awt.*;
import java.net.*;

public class Main extends JFrame
{
   JDesktopPane desktop;
 
   public Main() {
      desktop = new JDesktopPane(); 
      setContentPane(desktop);
      setBackgroundImage();
 
      // create internal frame with title bar
      createInternalFrame(true);
 
      // create internal frame without title bar
      createInternalFrame(false);
 
      setSize(new Dimension(500, 300));
      setLocation(100, 100);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent we) {
            System.exit(0); 
         }
      });
   }
 
   protected void setBackgroundImage() {
      try {
         ImageIcon icon = new ImageIcon(new URL("http://www.esus.com/images/mong.jpg"));
         JLabel label = new JLabel(icon);
         label.setBounds(0, 0, icon.getIconWidth(), icon.getIconHeight());
  
         desktop.add(label, new Integer(Integer.MIN_VALUE));
      } catch(MalformedURLException e) {
         System.out.println(e);
      }
   }
  
   protected void createInternalFrame(boolean titlebar) {
 
      JInternalFrame frame = new JInternalFrame("InternalFrame", 
         true,    // resizable
         true,    // closable
         true,    // maximizable
         true);   // iconifiable
      if (!titlebar) {
         javax.swing.plaf.InternalFrameUI ui = frame.getUI();
            ((javax.swing.plaf.basic.BasicInternalFrameUI)ui).setNorthPane(null);
      }
 
      frame.setVisible(true); 
      desktop.add(frame);
      frame.setSize(200, 200);
      try {
         frame.setSelected(true);
      } catch (java.beans.PropertyVetoException e) {}
   }
 
   public static void main(String []args) throws Exception {
      Main main = new Main();
      main.show();      
   }
}

Setting the margin of a JButton

Use the method setMargin and specify an Insets object with (bottom, left, right, top) margins.

Main.java:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
   
public class Main extends JFrame {
   JList list; 
 
   public Main() {
      getContentPane().setLayout(new FlowLayout());
 
      final JButton button = new JButton("OK!");
      button.setMargin(new Insets(100, 100, 100, 100));
      
      getContentPane().add(button);
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent event) {
            System.exit(0);   
         }      
      });
 
      setSize(400, 400);
   }
 
   public static void main(String[] args) {
      (new Main()).show();
   }
}

Refreshing the contents of a JList

JListExample.java:

 
// Created with JBuilder (c) Philip Craiger
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
/**
 * Title:        A JList Programming Example
 * Description:
 * Copyright:    Copyright (c) 2001
 * Company:
 * @author Dr. Philip Craiger
 * @version 1.0
 */
 
public class JListExample extends JFrame {
  private JButton btnMove = new JButton();
  private JButton bthRemove = new JButton();
 
  // Model View Controller: We change contents of the JList through
  // manipulation of a MODEL, not the actual JList.
  
 
  private DefaultListModel model_1 = new DefaultListModel();
  private DefaultListModel model_2 = new DefaultListModel();
 
  private JList jList1 = new JList(model_2);
  private JList jList2 = new JList(model_1);
  
  // JLists do not scroll by default.  We need to add them to
  // an encompassing JScrollPane
  private JScrollPane jScrollPane1 = new JScrollPane();
  private JScrollPane jScrollPane2 = new JScrollPane();
 
  public JListExample() {     // our constructor
    super("A JList Example"); // call to super constructor
    try {
      jbInit();
    }
    catch(Exception e) {
      e.printStackTrace();
    }
  }
 
  public static void main(String[] args) {
    JListExample foo = new JListExample();
    foo.setSize(new Dimension(450,200));
    foo.show();
  }
 
  private void jbInit() throws Exception {
 
  // Note we are adding and removing JList items from the MODEL
  // NOT directly from the JList.  Because JList is associated with the
  // model, the JList contents are updated automatically
 
    model_1.addElement("Java");
    model_1.addElement("Visual Basic");
    model_1.addElement("C++");
    model_1.addElement("C");
    model_1.addElement("Common LISP");
    model_1.addElement("Fortran");
    model_1.addElement("Pascal");
    model_1.addElement("Python");
    this.getContentPane().setLayout(null);
 
    btnMove.setText("Move >>");
    btnMove.setBounds(new Rectangle(150, 35, 98, 36));
    btnMove.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        btnMove_actionPerformed(e);
      }
    });
 
    bthRemove.setText("<< Remove");
    bthRemove.setBounds(new Rectangle(152, 87, 97, 36));
    bthRemove.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(ActionEvent e) {
        bthRemove_actionPerformed(e);
      }
    });
 
    jScrollPane1.setBounds(new Rectangle(286, 15, 109, 133));
    jScrollPane2.setBounds(new Rectangle(14, 15, 106, 136));
 
    // Allow user to select a single item from JList
    jList1.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
    jList2.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
 
    this.getContentPane().add(jScrollPane2, null);
    jScrollPane2.getViewport().add(jList2, null); // Must add JList
    this.getContentPane().add(jScrollPane1, null); // to a JScrollPane
    this.getContentPane().add(btnMove, null);
    this.getContentPane().add(bthRemove, null);
    jScrollPane1.getViewport().add(jList1, null); // JList to JScrollPane
    jList2.setSelectedIndex(0);
  }
 
  void btnMove_actionPerformed(ActionEvent e) {
    model_2.addElement(jList2.getSelectedValue());  // change the MODEL
    model_1.removeElement(jList2.getSelectedValue());  // change the MODEL
    jList2.setSelectedIndex(0);       // Highlight first item in JList
  }
 
  void bthRemove_actionPerformed(ActionEvent e) {
    model_1.addElement(jList1.getSelectedValue());  // change the MODEL
    model_2.removeElement(jList1.getSelectedValue()); // change the MODEL
    jList2.setSelectedIndex(0);       // Highlight first item in JList
  }
}

Catching the event when a JMenuItem has been selected

Add an ActionListener object. Here’s an example:

import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
   
public class Main extends JFrame implements ActionListener {
   public Main() {
      getContentPane().setLayout(new FlowLayout());
 
      JMenuBar menuBar = new JMenuBar();
      JMenu menu = new JMenu(&quot;menu&quot;);
      JMenuItem menuItem1 = new JMenuItem(&quot;option 1&quot;);
      JMenuItem menuItem2 = new JMenuItem(&quot;option 2&quot;);
      JMenuItem menuItem3 = new JMenuItem(&quot;option 3&quot;);
      menuItem1.addActionListener(this);
      menuItem2.addActionListener(this);
      menuItem3.addActionListener(this);
      menu.add(menuItem1);
      menu.add(menuItem2);
      menu.add(new JSeparator());
      menu.add(menuItem3);
      menuBar.add(menu);
 
      this.setJMenuBar(menuBar); 
 
      addWindowListener(new WindowAdapter() {
         public void windowClosing(WindowEvent event) {
            System.exit(0);   
         }      
      });
 
      setSize(400, 400);
   }

   public void actionPerformed(ActionEvent ae) {
      System.out.println(ae.getActionCommand() + &quot; selected!&quot;);
   }
 
   public static void main(String[] args) {
      (new Main()).show();
   }
}

Embedding a JSpinner inside a JTable cell

Main.java:

import javax.swing.table.*;
import java.awt.event.*;
import javax.swing.*;
import java.awt.*;
  
public class JSpinnerTableExample extends JFrame {
 
  public JSpinnerTableExample(){
    super( &amp;amp;quot;JSpinnerTable Example&amp;amp;quot; );
    
    SpinnerNumberModel spinnerModel1 = new SpinnerNumberModel(10.0, -500.0, 500.0, .5);
    SpinnerDateModel spinnerModel2 = new SpinnerDateModel();
 
    DefaultTableModel dtm = new DefaultTableModel();
    dtm.setDataVector(new Object[][]{{ spinnerModel1, &amp;amp;quot;JSpinner1&amp;amp;quot; },
                                     { spinnerModel2, &amp;amp;quot;JSpinner2&amp;amp;quot; }},
                      new Object[]{&amp;amp;quot;JSpinner&amp;amp;quot;,&amp;amp;quot;String&amp;amp;quot;});
                     
    JTable table = new JTable(dtm);
    table.getColumn(&amp;amp;quot;JSpinner&amp;amp;quot;).setCellRenderer(new SpinnerRenderer());
    table.getColumn(&amp;amp;quot;JSpinner&amp;amp;quot;).setCellEditor(new SpinnerEditor());
 
    table.setRowHeight(20);
    JScrollPane scroll = new JScrollPane(table);
    getContentPane().add(scroll);
 
    setSize( 400, 100 );
    setVisible(true);
  }
 
  public static void main(String[] args) {
    JSpinnerTableExample frame = new JSpinnerTableExample();
    frame.addWindowListener(new WindowAdapter() {
      public void windowClosing(WindowEvent e) {
        System.exit(0);
      }
    });
  }
}
 
class SpinnerRenderer extends JSpinner implements TableCellRenderer {
   public SpinnerRenderer() {
      setOpaque(true);
   }
  
   public Component getTableCellRendererComponent(JTable table, Object value,
                    boolean isSelected, boolean hasFocus, int row, int column) {
      setModel((SpinnerModel) value);
  
      return this;
   }
}
  
class SpinnerEditor extends AbstractCellEditor implements TableCellEditor {
   protected JSpinner spinner;
  
   public SpinnerEditor() {
      spinner = new JSpinner();
   }
 
   public Component getTableCellEditorComponent(JTable table, Object value,
                    boolean isSelected, int row, int column) {
      spinner.setModel((SpinnerModel) value);
 
      return spinner;
   }
 
   public Object getCellEditorValue() {
      SpinnerModel sm = spinner.getModel();
      return sm;
   }
}