Java Tutorial/Swing/SpringLayout

Define the right (east) and bottom (south) edges of the container

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;
public class SpringDemo3 {
  public static void main(String[] args) {
    JFrame frame = new JFrame("SpringDemo3");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Set up the content pane.
    Container contentPane = frame.getContentPane();
    SpringLayout layout = new SpringLayout();
    contentPane.setLayout(layout);
    // Create and add the components.
    JLabel label = new JLabel("Label: ");
    JTextField textField = new JTextField("Text field", 15);
    contentPane.add(label);
    contentPane.add(textField);
    // Adjust constraints for the label so it"s at (5,5).
    layout.putConstraint(SpringLayout.WEST, label, 5, SpringLayout.WEST, contentPane);
    layout.putConstraint(SpringLayout.NORTH, label, 5, SpringLayout.NORTH, contentPane);
    // Adjust constraints for the text field so it"s at
    // (<label"s right edge> + 5, 5).
    layout.putConstraint(SpringLayout.WEST, textField, 5, SpringLayout.EAST, label);
    layout.putConstraint(SpringLayout.NORTH, textField, 5, SpringLayout.NORTH, contentPane);
    // Adjust constraints for the content pane: Its right
    // edge should be 5 pixels beyond the text field"s right
    // edge, and its bottom edge should be 5 pixels beyond
    // the bottom edge of the tallest component (which we"ll
    // assume is textField).
    layout.putConstraint(SpringLayout.EAST, contentPane, 5, SpringLayout.EAST, textField);
    layout.putConstraint(SpringLayout.SOUTH, contentPane, 5, SpringLayout.SOUTH, textField);
    // Display the window.
    frame.pack();
    frame.setVisible(true);
  }
}

How to Use SpringLayout

Spring layouts do their job by defining relationships between the edges of components.

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;
public class SpringDemo1 {
  public static void main(String[] args) {
    JFrame frame = new JFrame("SpringDemo1");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Set up the content pane.
    Container contentPane = frame.getContentPane();
    SpringLayout layout = new SpringLayout();
    contentPane.setLayout(layout);
    contentPane.add(new JLabel("Label: "));
    contentPane.add(new JTextField("Text field", 15));
    // Display the window.
    frame.pack();
    frame.setVisible(true);
  }
}

Specifying locations for each component

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;
public class SpringDemo2 {
  public static void main(String[] args) {
    JFrame frame = new JFrame("SpringDemo2");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Set up the content pane.
    Container contentPane = frame.getContentPane();
    SpringLayout layout = new SpringLayout();
    contentPane.setLayout(layout);
    // Create and add the components.
    JLabel label = new JLabel("Label: ");
    JTextField textField = new JTextField("Text field", 15);
    contentPane.add(label);
    contentPane.add(textField);
    // Adjust constraints for the label so it"s at (5,5).
    layout.putConstraint(SpringLayout.WEST, label, 5, SpringLayout.WEST, contentPane);
    layout.putConstraint(SpringLayout.NORTH, label, 5, SpringLayout.NORTH, contentPane);
    // Adjust constraints for the text field so it"s at
    // (<label"s right edge> + 5, 5).
    layout.putConstraint(SpringLayout.WEST, textField, 5, SpringLayout.EAST, label);
    layout.putConstraint(SpringLayout.NORTH, textField, 5, SpringLayout.NORTH, contentPane);
    // Display the window.
    frame.pack();
    frame.setVisible(true);
  }
}

SpringLayout

1. SpringLayout allows you to attach "springs" to components.
2. Components are laid out relative to other components.
3. Each component added to the container can have an attached SpringLayout.Constraints.

import java.awt.ruponent;
import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.SpringLayout;
public class SpringSample {
  public static void main(String args[]) {
    JFrame frame = new JFrame("SpringLayout");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    Container contentPane = frame.getContentPane();
    SpringLayout layout = new SpringLayout();
    contentPane.setLayout(layout);
    Component left = new JLabel("Left");
    Component right = new JTextField(15);
    contentPane.add(left);
    contentPane.add(right);
    layout.putConstraint(SpringLayout.WEST, left, 10, SpringLayout.WEST, contentPane);
    layout.putConstraint(SpringLayout.NORTH, left, 25, SpringLayout.NORTH, contentPane);
    layout.putConstraint(SpringLayout.NORTH, right, 25, SpringLayout.NORTH, contentPane);
    layout.putConstraint(SpringLayout.WEST, right, 20, SpringLayout.EAST, left);
    frame.setSize(300, 100);
    frame.setVisible(true);
  }
}

SpringLayout Utilities

/*
 * (c) Copyright 2004 by Heng Yuan
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * ITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */
import java.awt.*;
import javax.swing.*;
/**
 * This code is from 
 * The source is at http://java.sun.ru/docs/books/tutorial/uiswing/layout/example-1dot4/SpringUtilities.java.
 * No copyright or license information was in the source file and it was from the tutorial.  Thus
 * assuming I could use it in this program.  Below is the original file header.  The file is
 * not modified other than reformating white spaces.
 * <p>
 * A 1.4 file that provides utility methods for
 * creating form- or grid-style layouts with SpringLayout.
 * These utilities are used by several programs, such as
 * SpringBox and SpringCompactGrid.
 * </p>
 * TODO: Although algorithm wise is correct, this class fails to address the problem of rounding
 * errors.  As the result, sometimes the last row can be mismatched with other rows.  The solution
 * to the problem is to force the alignment of edges.
 *
 * @see javax.swing.SpringLayout
 * @see cookxml.cookswing.creator.SpringGridCreator
 * @author Heng Yuan
 * @version $Id: SpringLayoutUtilities.java 215 2007-06-06 03:59:41Z coconut $
 * @since CookSwing 1.0
 */
public class SpringLayoutUtilities
{
  /**
   * A debugging utility that prints to stdout the component"s
   * minimum, preferred, and maximum sizes.
   */
  public static void printSizes (Component c)
  {
    System.out.println ("minimumSize = " + c.getMinimumSize ());
    System.out.println ("preferredSize = " + c.getPreferredSize ());
    System.out.println ("maximumSize = " + c.getMaximumSize ());
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code>
   * components of <code>parent</code> in
   * a grid. Each component is as big as the maximum
   * preferred width and height of the components.
   * The parent is made just big enough to fit them all.
   *
   * @param rows     number of rows
   * @param cols     number of columns
   * @param initialX x location to start the grid at
   * @param initialY y location to start the grid at
   * @param xPad     x padding between cells
   * @param yPad     y padding between cells
   */
  public static void makeGrid (Container parent,
                 int rows, int cols,
                 int initialX, int initialY,
                 int xPad, int yPad)
  {
    SpringLayout layout;
    try
    {
      layout = (SpringLayout)parent.getLayout ();
    }
    catch (ClassCastException exc)
    {
      System.err.println ("The first argument to makeGrid must use SpringLayout.");
      return;
    }
    Spring xPadSpring = Spring.constant (xPad);
    Spring yPadSpring = Spring.constant (yPad);
    Spring initialXSpring = Spring.constant (initialX);
    Spring initialYSpring = Spring.constant (initialY);
    int max = rows * cols;
    //Calculate Springs that are the max of the width/height so that all
    //cells have the same size.
    Spring maxWidthSpring = layout.getConstraints (parent.getComponent (0)).
        getWidth ();
    Spring maxHeightSpring = layout.getConstraints (parent.getComponent (0)).
        getWidth ();
    for (int i = 1; i < max; i++)
    {
      SpringLayout.Constraints cons = layout.getConstraints (parent.getComponent (i));
      maxWidthSpring = Spring.max (maxWidthSpring, cons.getWidth ());
      maxHeightSpring = Spring.max (maxHeightSpring, cons.getHeight ());
    }
    //Apply the new width/height Spring. This forces all the
    //components to have the same size.
    for (int i = 0; i < max; i++)
    {
      SpringLayout.Constraints cons = layout.getConstraints (parent.getComponent (i));
      cons.setWidth (maxWidthSpring);
      cons.setHeight (maxHeightSpring);
    }
    //Then adjust the x/y constraints of all the cells so that they
    //are aligned in a grid.
    SpringLayout.Constraints lastCons = null;
    SpringLayout.Constraints lastRowCons = null;
    for (int i = 0; i < max; i++)
    {
      SpringLayout.Constraints cons = layout.getConstraints (parent.getComponent (i));
      if (i % cols == 0)
      { //start of new row
        lastRowCons = lastCons;
        cons.setX (initialXSpring);
      }
      else
      { //x position depends on previous component
        cons.setX (Spring.sum (lastCons.getConstraint (SpringLayout.EAST),
                     xPadSpring));
      }
      if (i / cols == 0)
      { //first row
        cons.setY (initialYSpring);
      }
      else
      { //y position depends on previous row
        cons.setY (Spring.sum (lastRowCons.getConstraint (SpringLayout.SOUTH),
                     yPadSpring));
      }
      lastCons = cons;
    }
    //Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints (parent);
    pCons.setConstraint (SpringLayout.SOUTH,
               Spring.sum (Spring.constant (yPad),
                     lastCons.getConstraint (SpringLayout.SOUTH)));
    pCons.setConstraint (SpringLayout.EAST,
               Spring.sum (Spring.constant (xPad),
                     lastCons.getConstraint (SpringLayout.EAST)));
  }
  /* Used by makeCompactGrid. */
  private static SpringLayout.Constraints getConstraintsForCell (int row, int col,
                                   Container parent,
                                   int cols)
  {
    SpringLayout layout = (SpringLayout)parent.getLayout ();
    Component c = parent.getComponent (row * cols + col);
    return layout.getConstraints (c);
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code>
   * components of <code>parent</code> in
   * a grid. Each component in a column is as wide as the maximum
   * preferred width of the components in that column;
   * height is similarly determined for each row.
   * The parent is made just big enough to fit them all.
   *
   * @param rows     number of rows
   * @param cols     number of columns
   * @param initialX x location to start the grid at
   * @param initialY y location to start the grid at
   * @param xPad     x padding between cells
   * @param yPad     y padding between cells
   */
  public static void makeCompactGrid (Container parent,
                    int rows, int cols,
                    int initialX, int initialY,
                    int xPad, int yPad)
  {
    SpringLayout layout;
    try
    {
      layout = (SpringLayout)parent.getLayout ();
    }
    catch (ClassCastException exc)
    {
      System.err.println ("The first argument to makeCompactGrid must use SpringLayout.");
      return;
    }
    //Align all cells in each column and make them the same width.
    Spring x = Spring.constant (initialX);
    for (int c = 0; c < cols; c++)
    {
      Spring width = Spring.constant (0);
      for (int r = 0; r < rows; r++)
      {
        width = Spring.max (width,
                  getConstraintsForCell (r, c, parent, cols).
                  getWidth ());
      }
      for (int r = 0; r < rows; r++)
      {
        SpringLayout.Constraints constraints =
            getConstraintsForCell (r, c, parent, cols);
        constraints.setX (x);
        constraints.setWidth (width);
      }
      x = Spring.sum (x, Spring.sum (width, Spring.constant (xPad)));
    }
    //Align all cells in each row and make them the same height.
    Spring y = Spring.constant (initialY);
    for (int r = 0; r < rows; r++)
    {
      Spring height = Spring.constant (0);
      for (int c = 0; c < cols; c++)
      {
        height = Spring.max (height,
                   getConstraintsForCell (r, c, parent, cols).
                   getHeight ());
      }
      for (int c = 0; c < cols; c++)
      {
        SpringLayout.Constraints constraints =
            getConstraintsForCell (r, c, parent, cols);
        constraints.setY (y);
        constraints.setHeight (height);
      }
      y = Spring.sum (y, Spring.sum (height, Spring.constant (yPad)));
    }
    //Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints (parent);
    pCons.setConstraint (SpringLayout.SOUTH, y);
    pCons.setConstraint (SpringLayout.EAST, x);
  }
}

Springs and Component Size

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

import java.awt.ruponent;
import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JTextField;
import javax.swing.Spring;
import javax.swing.SpringLayout;
public class SpringDemo4 {
  public static void main(String[] args) {
    JFrame frame = new JFrame("SpringDemo4");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Set up the content pane.
    Container contentPane = frame.getContentPane();
    SpringLayout layout = new SpringLayout();
    contentPane.setLayout(layout);
    // Create and add the components.
    JLabel label = new JLabel("Label: ");
    JTextField textField = new JTextField("Text field", 15);
    contentPane.add(label);
    contentPane.add(textField);
    // Adjust constraints for the label so it"s at (5,5).
    SpringLayout.Constraints labelCons = layout.getConstraints(label);
    labelCons.setX(Spring.constant(5));
    labelCons.setY(Spring.constant(5));
    // Adjust constraints for the text field so it"s at
    // (<label"s right edge> + 5, 5).
    SpringLayout.Constraints textFieldCons = layout.getConstraints(textField);
    textFieldCons.setX(Spring.sum(Spring.constant(5), labelCons.getConstraint(SpringLayout.EAST)));
    textFieldCons.setY(Spring.constant(5));
    // Adjust constraints for the content pane.
    setContainerSize(contentPane, 5);
    // Display the window.
    frame.pack();
    frame.setVisible(true);
  }
  public static void setContainerSize(Container parent, int pad) {
    SpringLayout layout = (SpringLayout) parent.getLayout();
    Component[] components = parent.getComponents();
    Spring maxHeightSpring = Spring.constant(0);
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    // Set the container"s right edge to the right edge
    // of its rightmost component + padding.
    Component rightmost = components[components.length - 1];
    SpringLayout.Constraints rCons = layout.getConstraints(rightmost);
    pCons.setConstraint(SpringLayout.EAST, Spring.sum(Spring.constant(pad), rCons
        .getConstraint(SpringLayout.EAST)));
    // Set the container"s bottom edge to the bottom edge
    // of its tallest component + padding.
    for (int i = 0; i < components.length; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(components[i]);
      maxHeightSpring = Spring.max(maxHeightSpring, cons.getConstraint(SpringLayout.SOUTH));
    }
    pCons.setConstraint(SpringLayout.SOUTH, Spring.sum(Spring.constant(pad), maxHeightSpring));
  }
}

Using a SpringLayout Manager

Allows components to have their position defined by "springs" or "struts " fixed to an edge of the container or another component in the container.

import java.awt.Container;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.Spring;
import javax.swing.SpringLayout;
public class TrySpringLayout {
  public static void main(String[] args) {
    JFrame aWindow = new JFrame("This is a Spring Layout");
    aWindow.setBounds(30, 30, 300, 300);
    aWindow.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    SpringLayout layout = new SpringLayout();
    Container content = aWindow.getContentPane();
    content.setLayout(layout);
    JButton[] buttons = new JButton[6];
    SpringLayout.Constraints constr = null;
    for (int i = 0; i < buttons.length; i++) {
      buttons[i] = new JButton("Press " + (i + 1));
      content.add(buttons[i]);
    }
    Spring xSpring = Spring.constant(5, 15, 25);
    Spring ySpring = Spring.constant(10, 30, 50);
    constr = layout.getConstraints(buttons[0]);
    constr.setX(xSpring);
    constr.setY(ySpring);
    // Hook buttons together with springs
    for (int i = 1; i < buttons.length; i++) {
      constr = layout.getConstraints(buttons[i]);
      layout.putConstraint(SpringLayout.WEST, buttons[i], xSpring, SpringLayout.EAST,
          buttons[i - 1]);
      layout.putConstraint(SpringLayout.NORTH, buttons[i], ySpring, SpringLayout.SOUTH,
          buttons[i - 1]);
    }
    aWindow.setVisible(true); // Display the window
  }
}

Using SpringLayout to create a compact grid

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

/*
 * A 1.4 application that uses SpringLayout to create a compact grid.
 * Other files required: SpringUtilities.java.
 */
import javax.swing.*;
import java.awt.*;
public class SpringCompactGrid {
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        JPanel panel = new JPanel(new SpringLayout());
        int rows = 10;
        int cols = 10;
        for (int r = 0; r < rows; r++) {
            for (int c = 0; c < cols; c++) {
                int anInt = (int) Math.pow(r, c);
                JTextField textField =
                        new JTextField(Integer.toString(anInt));
                panel.add(textField);
            }
        }
        //Lay out the panel.
        SpringUtilities.makeCompactGrid(panel, //parent
                                        rows, cols,
                                        3, 3,  //initX, initY
                                        3, 3); //xPad, yPad
        //Create and set up the window.
        JFrame frame = new JFrame("SpringCompactGrid");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Set up the content pane.
        panel.setOpaque(true); //content panes must be opaque
        frame.setContentPane(panel);
        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application"s GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}
class SpringUtilities {
  /**
   * A debugging utility that prints to stdout the component"s minimum,
   * preferred, and maximum sizes.
   */
  public static void printSizes(Component c) {
    System.out.println("minimumSize = " + c.getMinimumSize());
    System.out.println("preferredSize = " + c.getPreferredSize());
    System.out.println("maximumSize = " + c.getMaximumSize());
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component is as big as the maximum
   * preferred width and height of the components. The parent is made just big
   * enough to fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeGrid(Container parent, int rows, int cols, int initialX, int initialY,
      int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeGrid must use SpringLayout.");
      return;
    }
    Spring xPadSpring = Spring.constant(xPad);
    Spring yPadSpring = Spring.constant(yPad);
    Spring initialXSpring = Spring.constant(initialX);
    Spring initialYSpring = Spring.constant(initialY);
    int max = rows * cols;
    // Calculate Springs that are the max of the width/height so that all
    // cells have the same size.
    Spring maxWidthSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    Spring maxHeightSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    for (int i = 1; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      maxWidthSpring = Spring.max(maxWidthSpring, cons.getWidth());
      maxHeightSpring = Spring.max(maxHeightSpring, cons.getHeight());
    }
    // Apply the new width/height Spring. This forces all the
    // components to have the same size.
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      cons.setWidth(maxWidthSpring);
      cons.setHeight(maxHeightSpring);
    }
    // Then adjust the x/y constraints of all the cells so that they
    // are aligned in a grid.
    SpringLayout.Constraints lastCons = null;
    SpringLayout.Constraints lastRowCons = null;
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      if (i % cols == 0) { // start of new row
        lastRowCons = lastCons;
        cons.setX(initialXSpring);
      } else { // x position depends on previous component
        cons.setX(Spring.sum(lastCons.getConstraint(SpringLayout.EAST), xPadSpring));
      }
      if (i / cols == 0) { // first row
        cons.setY(initialYSpring);
      } else { // y position depends on previous row
        cons.setY(Spring.sum(lastRowCons.getConstraint(SpringLayout.SOUTH), yPadSpring));
      }
      lastCons = cons;
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, Spring.sum(Spring.constant(yPad), lastCons
        .getConstraint(SpringLayout.SOUTH)));
    pCons.setConstraint(SpringLayout.EAST, Spring.sum(Spring.constant(xPad), lastCons
        .getConstraint(SpringLayout.EAST)));
  }
  /* Used by makeCompactGrid. */
  private static SpringLayout.Constraints getConstraintsForCell(int row, int col, Container parent,
      int cols) {
    SpringLayout layout = (SpringLayout) parent.getLayout();
    Component c = parent.getComponent(row * cols + col);
    return layout.getConstraints(c);
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component in a column is as wide as
   * the maximum preferred width of the components in that column; height is
   * similarly determined for each row. The parent is made just big enough to
   * fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeCompactGrid(Container parent, int rows, int cols, int initialX,
      int initialY, int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeCompactGrid must use SpringLayout.");
      return;
    }
    // Align all cells in each column and make them the same width.
    Spring x = Spring.constant(initialX);
    for (int c = 0; c < cols; c++) {
      Spring width = Spring.constant(0);
      for (int r = 0; r < rows; r++) {
        width = Spring.max(width, getConstraintsForCell(r, c, parent, cols).getWidth());
      }
      for (int r = 0; r < rows; r++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setX(x);
        constraints.setWidth(width);
      }
      x = Spring.sum(x, Spring.sum(width, Spring.constant(xPad)));
    }
    // Align all cells in each row and make them the same height.
    Spring y = Spring.constant(initialY);
    for (int r = 0; r < rows; r++) {
      Spring height = Spring.constant(0);
      for (int c = 0; c < cols; c++) {
        height = Spring.max(height, getConstraintsForCell(r, c, parent, cols).getHeight());
      }
      for (int c = 0; c < cols; c++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setY(y);
        constraints.setHeight(height);
      }
      y = Spring.sum(y, Spring.sum(height, Spring.constant(yPad)));
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, y);
    pCons.setConstraint(SpringLayout.EAST, x);
  }
}

using SpringLayout to create a forms-type layout

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

/*
 * A 1.4 application that uses SpringLayout to create a forms-type layout.
 * Other files required: SpringUtilities.java.
 */
import javax.swing.*;
import java.awt.*;
public class SpringForm {
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        String[] labels = {"Name: ", "Fax: ", "Email: ", "Address: "};
        int numPairs = labels.length;
        //Create and populate the panel.
        JPanel p = new JPanel(new SpringLayout());
        for (int i = 0; i < numPairs; i++) {
            JLabel l = new JLabel(labels[i], JLabel.TRAILING);
            p.add(l);
            JTextField textField = new JTextField(10);
            l.setLabelFor(textField);
            p.add(textField);
        }
        //Lay out the panel.
        SpringUtilities.makeCompactGrid(p,
                                        numPairs, 2, //rows, cols
                                        6, 6,        //initX, initY
                                        6, 6);       //xPad, yPad
        //Create and set up the window.
        JFrame frame = new JFrame("SpringForm");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Set up the content pane.
        p.setOpaque(true);  //content panes must be opaque
        frame.setContentPane(p);
        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application"s GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}

class SpringUtilities {
  /**
   * A debugging utility that prints to stdout the component"s minimum,
   * preferred, and maximum sizes.
   */
  public static void printSizes(Component c) {
    System.out.println("minimumSize = " + c.getMinimumSize());
    System.out.println("preferredSize = " + c.getPreferredSize());
    System.out.println("maximumSize = " + c.getMaximumSize());
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component is as big as the maximum
   * preferred width and height of the components. The parent is made just big
   * enough to fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeGrid(Container parent, int rows, int cols, int initialX, int initialY,
      int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeGrid must use SpringLayout.");
      return;
    }
    Spring xPadSpring = Spring.constant(xPad);
    Spring yPadSpring = Spring.constant(yPad);
    Spring initialXSpring = Spring.constant(initialX);
    Spring initialYSpring = Spring.constant(initialY);
    int max = rows * cols;
    // Calculate Springs that are the max of the width/height so that all
    // cells have the same size.
    Spring maxWidthSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    Spring maxHeightSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    for (int i = 1; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      maxWidthSpring = Spring.max(maxWidthSpring, cons.getWidth());
      maxHeightSpring = Spring.max(maxHeightSpring, cons.getHeight());
    }
    // Apply the new width/height Spring. This forces all the
    // components to have the same size.
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      cons.setWidth(maxWidthSpring);
      cons.setHeight(maxHeightSpring);
    }
    // Then adjust the x/y constraints of all the cells so that they
    // are aligned in a grid.
    SpringLayout.Constraints lastCons = null;
    SpringLayout.Constraints lastRowCons = null;
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      if (i % cols == 0) { // start of new row
        lastRowCons = lastCons;
        cons.setX(initialXSpring);
      } else { // x position depends on previous component
        cons.setX(Spring.sum(lastCons.getConstraint(SpringLayout.EAST), xPadSpring));
      }
      if (i / cols == 0) { // first row
        cons.setY(initialYSpring);
      } else { // y position depends on previous row
        cons.setY(Spring.sum(lastRowCons.getConstraint(SpringLayout.SOUTH), yPadSpring));
      }
      lastCons = cons;
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, Spring.sum(Spring.constant(yPad), lastCons
        .getConstraint(SpringLayout.SOUTH)));
    pCons.setConstraint(SpringLayout.EAST, Spring.sum(Spring.constant(xPad), lastCons
        .getConstraint(SpringLayout.EAST)));
  }
  /* Used by makeCompactGrid. */
  private static SpringLayout.Constraints getConstraintsForCell(int row, int col, Container parent,
      int cols) {
    SpringLayout layout = (SpringLayout) parent.getLayout();
    Component c = parent.getComponent(row * cols + col);
    return layout.getConstraints(c);
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component in a column is as wide as
   * the maximum preferred width of the components in that column; height is
   * similarly determined for each row. The parent is made just big enough to
   * fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeCompactGrid(Container parent, int rows, int cols, int initialX,
      int initialY, int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeCompactGrid must use SpringLayout.");
      return;
    }
    // Align all cells in each column and make them the same width.
    Spring x = Spring.constant(initialX);
    for (int c = 0; c < cols; c++) {
      Spring width = Spring.constant(0);
      for (int r = 0; r < rows; r++) {
        width = Spring.max(width, getConstraintsForCell(r, c, parent, cols).getWidth());
      }
      for (int r = 0; r < rows; r++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setX(x);
        constraints.setWidth(width);
      }
      x = Spring.sum(x, Spring.sum(width, Spring.constant(xPad)));
    }
    // Align all cells in each row and make them the same height.
    Spring y = Spring.constant(initialY);
    for (int r = 0; r < rows; r++) {
      Spring height = Spring.constant(0);
      for (int c = 0; c < cols; c++) {
        height = Spring.max(height, getConstraintsForCell(r, c, parent, cols).getHeight());
      }
      for (int c = 0; c < cols; c++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setY(y);
        constraints.setHeight(height);
      }
      y = Spring.sum(y, Spring.sum(height, Spring.constant(yPad)));
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, y);
    pCons.setConstraint(SpringLayout.EAST, x);
  }
}

Using SpringLayout to create a single row

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

/*
 * A 1.4 application that uses SpringLayout to create a single row
 * of components, similar to that produced by a horizontal BoxLayout.
 * Other files required: SpringUtilities.java.
 */
import javax.swing.*;
import java.awt.*;
public class SpringBox {
    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("SpringBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //Set up the content pane.
        Container contentPane = frame.getContentPane();
        contentPane.setLayout(new SpringLayout());
        //Add the buttons.
        contentPane.add(new JButton("Button 1"));
        contentPane.add(new JButton("Button 2"));
        contentPane.add(new JButton("Button 3"));
        contentPane.add(new JButton("Long-Named Button 4"));
        contentPane.add(new JButton("5"));
        //Lay out the buttons in one row and as many columns
        //as necessary, with 6 pixels of padding all around.
        SpringUtilities.makeCompactGrid(contentPane, 1,
                                        contentPane.getComponentCount(),
                                        6, 6, 6, 6);
        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application"s GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
            }
        });
    }
}
class SpringUtilities {
  /**
   * A debugging utility that prints to stdout the component"s minimum,
   * preferred, and maximum sizes.
   */
  public static void printSizes(Component c) {
    System.out.println("minimumSize = " + c.getMinimumSize());
    System.out.println("preferredSize = " + c.getPreferredSize());
    System.out.println("maximumSize = " + c.getMaximumSize());
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component is as big as the maximum
   * preferred width and height of the components. The parent is made just big
   * enough to fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeGrid(Container parent, int rows, int cols, int initialX, int initialY,
      int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeGrid must use SpringLayout.");
      return;
    }
    Spring xPadSpring = Spring.constant(xPad);
    Spring yPadSpring = Spring.constant(yPad);
    Spring initialXSpring = Spring.constant(initialX);
    Spring initialYSpring = Spring.constant(initialY);
    int max = rows * cols;
    // Calculate Springs that are the max of the width/height so that all
    // cells have the same size.
    Spring maxWidthSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    Spring maxHeightSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    for (int i = 1; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      maxWidthSpring = Spring.max(maxWidthSpring, cons.getWidth());
      maxHeightSpring = Spring.max(maxHeightSpring, cons.getHeight());
    }
    // Apply the new width/height Spring. This forces all the
    // components to have the same size.
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      cons.setWidth(maxWidthSpring);
      cons.setHeight(maxHeightSpring);
    }
    // Then adjust the x/y constraints of all the cells so that they
    // are aligned in a grid.
    SpringLayout.Constraints lastCons = null;
    SpringLayout.Constraints lastRowCons = null;
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      if (i % cols == 0) { // start of new row
        lastRowCons = lastCons;
        cons.setX(initialXSpring);
      } else { // x position depends on previous component
        cons.setX(Spring.sum(lastCons.getConstraint(SpringLayout.EAST), xPadSpring));
      }
      if (i / cols == 0) { // first row
        cons.setY(initialYSpring);
      } else { // y position depends on previous row
        cons.setY(Spring.sum(lastRowCons.getConstraint(SpringLayout.SOUTH), yPadSpring));
      }
      lastCons = cons;
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, Spring.sum(Spring.constant(yPad), lastCons
        .getConstraint(SpringLayout.SOUTH)));
    pCons.setConstraint(SpringLayout.EAST, Spring.sum(Spring.constant(xPad), lastCons
        .getConstraint(SpringLayout.EAST)));
  }
  /* Used by makeCompactGrid. */
  private static SpringLayout.Constraints getConstraintsForCell(int row, int col, Container parent,
      int cols) {
    SpringLayout layout = (SpringLayout) parent.getLayout();
    Component c = parent.getComponent(row * cols + col);
    return layout.getConstraints(c);
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component in a column is as wide as
   * the maximum preferred width of the components in that column; height is
   * similarly determined for each row. The parent is made just big enough to
   * fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeCompactGrid(Container parent, int rows, int cols, int initialX,
      int initialY, int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeCompactGrid must use SpringLayout.");
      return;
    }
    // Align all cells in each column and make them the same width.
    Spring x = Spring.constant(initialX);
    for (int c = 0; c < cols; c++) {
      Spring width = Spring.constant(0);
      for (int r = 0; r < rows; r++) {
        width = Spring.max(width, getConstraintsForCell(r, c, parent, cols).getWidth());
      }
      for (int r = 0; r < rows; r++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setX(x);
        constraints.setWidth(width);
      }
      x = Spring.sum(x, Spring.sum(width, Spring.constant(xPad)));
    }
    // Align all cells in each row and make them the same height.
    Spring y = Spring.constant(initialY);
    for (int r = 0; r < rows; r++) {
      Spring height = Spring.constant(0);
      for (int c = 0; c < cols; c++) {
        height = Spring.max(height, getConstraintsForCell(r, c, parent, cols).getHeight());
      }
      for (int c = 0; c < cols; c++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setY(y);
        constraints.setHeight(height);
      }
      y = Spring.sum(y, Spring.sum(height, Spring.constant(yPad)));
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, y);
    pCons.setConstraint(SpringLayout.EAST, x);
  }
}

Using SpringLayout to lay out a grid

/*
 *
 * Copyright (c) 1998 Sun Microsystems, Inc. All Rights Reserved.
 *
 * Sun grants you ("Licensee") a non-exclusive, royalty free, license to use,
 * modify and redistribute this software in source and binary code form,
 * provided that i) this copyright notice and license appear on all copies of
 * the software; and ii) Licensee does not utilize the software in a manner
 * which is disparaging to Sun.
 *
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING ANY
 * IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR
 * NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN AND ITS LICENSORS SHALL NOT BE
 * LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING
 * OR DISTRIBUTING THE SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR ITS
 * LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR DIRECT,
 * INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER
 * CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY, ARISING OUT OF THE USE OF
 * OR INABILITY TO USE SOFTWARE, EVEN IF SUN HAS BEEN ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGES.
 *
 * This software is not designed or intended for use in on-line control of
 * aircraft, air traffic, aircraft navigation or aircraft communications; or in
 * the design, construction, operation or maintenance of any nuclear
 * facility. Licensee represents and warrants that it will not use or
 * redistribute the Software for such purposes.
 */

/*
 * A 1.4 application that uses SpringLayout to lay out a grid.
 * Other files required: SpringUtilities.java
 */
import java.awt.ruponent;
import java.awt.Container;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.Spring;
import javax.swing.SpringLayout;
public class SpringGrid {
  /**
   * Create the GUI and show it. For thread safety, this method should be
   * invoked from the event-dispatching thread.
   */
  private static void createAndShowGUI() {
    // Create the panel and populate it.
    JPanel panel = new JPanel(new SpringLayout());
    for (int i = 0; i < 9; i++) {
      JTextField textField = new JTextField(Integer.toString(i));
      // Make the 4th field extra big.
      if (i == 4) {
        textField.setText("This one is extra long.");
      }
      panel.add(textField);
    }
    // Lay out the panel.
    SpringUtilities.makeGrid(panel, 3, 3, // rows, cols
        5, 5, // initialX, initialY
        5, 5);// xPad, yPad
    // Create and set up the window.
    JFrame frame = new JFrame("SpringGrid");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    // Set up the content pane.
    panel.setOpaque(true); // content panes must be opaque
    frame.setContentPane(panel);
    // Display the window.
    frame.pack();
    frame.setVisible(true);
  }
  public static void main(String[] args) {
    // Schedule a job for the event-dispatching thread:
    // creating and showing this application"s GUI.
    javax.swing.SwingUtilities.invokeLater(new Runnable() {
      public void run() {
        createAndShowGUI();
      }
    });
  }
}
class SpringUtilities {
  /**
   * A debugging utility that prints to stdout the component"s minimum,
   * preferred, and maximum sizes.
   */
  public static void printSizes(Component c) {
    System.out.println("minimumSize = " + c.getMinimumSize());
    System.out.println("preferredSize = " + c.getPreferredSize());
    System.out.println("maximumSize = " + c.getMaximumSize());
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component is as big as the maximum
   * preferred width and height of the components. The parent is made just big
   * enough to fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeGrid(Container parent, int rows, int cols, int initialX, int initialY,
      int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeGrid must use SpringLayout.");
      return;
    }
    Spring xPadSpring = Spring.constant(xPad);
    Spring yPadSpring = Spring.constant(yPad);
    Spring initialXSpring = Spring.constant(initialX);
    Spring initialYSpring = Spring.constant(initialY);
    int max = rows * cols;
    // Calculate Springs that are the max of the width/height so that all
    // cells have the same size.
    Spring maxWidthSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    Spring maxHeightSpring = layout.getConstraints(parent.getComponent(0)).getWidth();
    for (int i = 1; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      maxWidthSpring = Spring.max(maxWidthSpring, cons.getWidth());
      maxHeightSpring = Spring.max(maxHeightSpring, cons.getHeight());
    }
    // Apply the new width/height Spring. This forces all the
    // components to have the same size.
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      cons.setWidth(maxWidthSpring);
      cons.setHeight(maxHeightSpring);
    }
    // Then adjust the x/y constraints of all the cells so that they
    // are aligned in a grid.
    SpringLayout.Constraints lastCons = null;
    SpringLayout.Constraints lastRowCons = null;
    for (int i = 0; i < max; i++) {
      SpringLayout.Constraints cons = layout.getConstraints(parent.getComponent(i));
      if (i % cols == 0) { // start of new row
        lastRowCons = lastCons;
        cons.setX(initialXSpring);
      } else { // x position depends on previous component
        cons.setX(Spring.sum(lastCons.getConstraint(SpringLayout.EAST), xPadSpring));
      }
      if (i / cols == 0) { // first row
        cons.setY(initialYSpring);
      } else { // y position depends on previous row
        cons.setY(Spring.sum(lastRowCons.getConstraint(SpringLayout.SOUTH), yPadSpring));
      }
      lastCons = cons;
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, Spring.sum(Spring.constant(yPad), lastCons
        .getConstraint(SpringLayout.SOUTH)));
    pCons.setConstraint(SpringLayout.EAST, Spring.sum(Spring.constant(xPad), lastCons
        .getConstraint(SpringLayout.EAST)));
  }
  /* Used by makeCompactGrid. */
  private static SpringLayout.Constraints getConstraintsForCell(int row, int col, Container parent,
      int cols) {
    SpringLayout layout = (SpringLayout) parent.getLayout();
    Component c = parent.getComponent(row * cols + col);
    return layout.getConstraints(c);
  }
  /**
   * Aligns the first <code>rows</code> * <code>cols</code> components of
   * <code>parent</code> in a grid. Each component in a column is as wide as
   * the maximum preferred width of the components in that column; height is
   * similarly determined for each row. The parent is made just big enough to
   * fit them all.
   * 
   * @param rows
   *          number of rows
   * @param cols
   *          number of columns
   * @param initialX
   *          x location to start the grid at
   * @param initialY
   *          y location to start the grid at
   * @param xPad
   *          x padding between cells
   * @param yPad
   *          y padding between cells
   */
  public static void makeCompactGrid(Container parent, int rows, int cols, int initialX,
      int initialY, int xPad, int yPad) {
    SpringLayout layout;
    try {
      layout = (SpringLayout) parent.getLayout();
    } catch (ClassCastException exc) {
      System.err.println("The first argument to makeCompactGrid must use SpringLayout.");
      return;
    }
    // Align all cells in each column and make them the same width.
    Spring x = Spring.constant(initialX);
    for (int c = 0; c < cols; c++) {
      Spring width = Spring.constant(0);
      for (int r = 0; r < rows; r++) {
        width = Spring.max(width, getConstraintsForCell(r, c, parent, cols).getWidth());
      }
      for (int r = 0; r < rows; r++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setX(x);
        constraints.setWidth(width);
      }
      x = Spring.sum(x, Spring.sum(width, Spring.constant(xPad)));
    }
    // Align all cells in each row and make them the same height.
    Spring y = Spring.constant(initialY);
    for (int r = 0; r < rows; r++) {
      Spring height = Spring.constant(0);
      for (int c = 0; c < cols; c++) {
        height = Spring.max(height, getConstraintsForCell(r, c, parent, cols).getHeight());
      }
      for (int c = 0; c < cols; c++) {
        SpringLayout.Constraints constraints = getConstraintsForCell(r, c, parent, cols);
        constraints.setY(y);
        constraints.setHeight(height);
      }
      y = Spring.sum(y, Spring.sum(height, Spring.constant(yPad)));
    }
    // Set the parent"s size.
    SpringLayout.Constraints pCons = layout.getConstraints(parent);
    pCons.setConstraint(SpringLayout.SOUTH, y);
    pCons.setConstraint(SpringLayout.EAST, x);
  }
}