import java.awt.Container;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.Spring;
import javax.swing.SpringLayout;


public class SpringLayout_3 extends JFrame {

 private static final long serialVersionUID = -6045918631932051025L;

 public SpringLayout_3() {
  // TODO Auto-generated constructor stub
  Container container = getContentPane();
  SpringLayout springLayout = new SpringLayout();
  container.setLayout(springLayout);
  JLabel topicLabel = new JLabel("主题 :");
  JLabel contentLabel = new JLabel("内容 :");
  final JTextField textField = new JTextField(30);
  JTextArea textArea = new JTextArea(3, 30);
  JScrollPane scrollPane = new JScrollPane();
  scrollPane.setViewportView(textArea);
  textArea.setLineWrap(true);
  final JButton confirmButton = new JButton("取消");
  JButton cancelButton = new JButton("确认");
  Spring st = Spring.constant(10);
  Spring st2 = Spring.constant(30);
  container.add(topicLabel);
  springLayout.putConstraint(SpringLayout.NORTH, topicLabel, st, 
    SpringLayout.NORTH, container);
  springLayout.putConstraint(SpringLayout.WEST, topicLabel, st, 
    SpringLayout.WEST, container);
  container.add(textField);
  springLayout.putConstraint(SpringLayout.WEST, textField, st2, 
    SpringLayout.EAST, topicLabel);
  springLayout.putConstraint(SpringLayout.NORTH, textField, 0, 
    SpringLayout.NORTH, topicLabel);
  springLayout.putConstraint(SpringLayout.EAST, textField, Spring.minus(st), 
    SpringLayout.EAST, container);
  container.add(contentLabel);
  springLayout.putConstraint(SpringLayout.WEST, contentLabel, 0, 
    SpringLayout.WEST, topicLabel);
  springLayout.putConstraint(SpringLayout.NORTH, contentLabel, st, 
    SpringLayout.SOUTH, topicLabel);
  container.add(scrollPane);
  springLayout.putConstraint(SpringLayout.NORTH, scrollPane, 0, 
    SpringLayout.NORTH, contentLabel);
  springLayout.putConstraint(SpringLayout.WEST, scrollPane, 0, 
    SpringLayout.WEST, textField);
  springLayout.putConstraint(SpringLayout.EAST, scrollPane, Spring.minus(st), 
    SpringLayout.EAST, container);
  container.add(confirmButton);
  springLayout.putConstraint(SpringLayout.SOUTH, scrollPane, Spring.minus(st), 
    SpringLayout.NORTH, confirmButton);
  springLayout.putConstraint(SpringLayout.EAST, confirmButton, Spring.minus(st), 
    SpringLayout.EAST, container);
  springLayout.putConstraint(SpringLayout.SOUTH, confirmButton, Spring.minus(st), 
    SpringLayout.SOUTH, container);
  container.add(cancelButton);
  springLayout.putConstraint(SpringLayout.EAST, cancelButton, Spring.minus(st), 
    SpringLayout.WEST, confirmButton);
  springLayout.putConstraint(SpringLayout.NORTH, cancelButton, 0, 
    SpringLayout.NORTH, confirmButton); 
  
  // make the text field focused every time the window is activated
  addWindowFocusListener(new WindowAdapter() {

   @Override
   public void windowGainedFocus(WindowEvent e) {
    // TODO Auto-generated method stub
    textField.requestFocus();
   }

  });
 }

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  SpringLayout_3 frame = new SpringLayout_3();
  frame.setTitle("使用弹簧布局管理器");
  frame.setVisible(true);
  frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
  frame.setBounds(100, 100, 600, 300);
 }

}