硬件领域出现了单片式计算机系统

20世纪90年代，硬件领域出现了单片式计算机系统，这种价格低廉的系统一出现就立即引起了自动控制领域人员的注意，因为使用它可以大幅度提升消费类电子产品（如电视机顶盒、面包烤箱、移动电话等）的智能化程度。Sun公司为了抢占市场先机，在1991年成立了一个称为Green的项目小组，帕特里克、詹姆斯•高斯林、麦克•舍林丹和其他几个工程师一起组成的工作小组在加利福尼亚州门洛帕克市沙丘路的一个小工作室里面研究开发新技术，专攻计算机在家电产品上的嵌入式应用。

package Com.SwingTest;


import java.awt.BorderLayout;
import java.awt.GridBagConstraints;
import java.awt.GridBagLayout;
import java.awt.GridLayout;
import java.awt.Insets;
import java.awt.event.ActionEvent;
import java.util.Arrays;
import java.util.List;

import javax.swing.AbstractAction;
import javax.swing.Action;
import javax.swing.BorderFactory;
import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.JPanel;
import javax.swing.JPasswordField;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
import javax.swing.UIManager;


/**
* @author Administrator
*
*/
public class SwingText_11 extends JPanel {

    private static final String LABEL_USERNAME = "用户账号：";
    private static final String LABEL_PASSWORD = "用户密码：";

    private static final String LABEL_OK = "确定";
    private static final String LABEL_Cancel = "取消";

    private static final int FIELD_COLS = 20;

    private JTextField fieldUsername;
    private JPasswordField fieldPassword;

    private Action actionOK;
    private Action actionCancel;
    
    
    public static void main(String[] args) {

        SwingUtilities.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (Exception e) {
                    e.printStackTrace();
                }
                JFrame test = new JFrame("欢迎进入本系统");
                test.setContentPane(new SwingText_11());
                test.pack();
                test.setResizable(false);
                test.setLocationRelativeTo(null);
                test.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
                test.setVisible(true);
            }
        });
    }



    SwingText_11() {

        super(new BorderLayout(5, 5));
        assert SwingUtilities.isEventDispatchThread();
        // 文本框
        fieldUsername = new JTextField(FIELD_COLS);
        // 密码框
        fieldPassword = new JPasswordField(FIELD_COLS);

        actionOK = new AbstractAction(LABEL_OK) {
            @Override
            public void actionPerformed(ActionEvent e) {
                // @TODO to be implemented. 实现确认按钮的操作
                //TODO
                String text = fieldUsername.getText();
                if (text.isEmpty()) {
                    JOptionPane.showMessageDialog(null, "用户名不能为空！", "提示", JOptionPane.ERROR_MESSAGE);
                    return;
                }
                
                JOptionPane.showMessageDialog(null, "这是一个假登录"+text, "提示", JOptionPane.ERROR_MESSAGE); 
            }
        };

        actionCancel = new AbstractAction(LABEL_Cancel) {
            @Override
            public void actionPerformed(ActionEvent e) {
                // @TODO to be implemented. 实现取消按钮的操作
                //退出程序
                System.exit(0);
            }
        };
        //  BorderLayout.NORTH 这是指定向北浮动
        add(layoutText(Arrays.asList( "第一行文字", "第二行文字", "第三行文字")), BorderLayout.NORTH);
        add(layoutFields(), BorderLayout.CENTER);
        add(layoutControl(), BorderLayout.SOUTH);

        setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
    }

    private JComponent layoutControl() {
        // 控件布局  
        JComponent result = new JPanel();
        // 这里是确认 和 取消的按钮
        result.add(new JButton(actionOK));
        result.add(new JButton(actionCancel));

        return result;
    }

    private JComponent layoutFields() {
        // 布局位置
        JComponent result = new JPanel(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();

        gbc.gridx = 0;
        gbc.gridy = 0;
        //固定 向西
        gbc.anchor = GridBagConstraints.WEST;
        //是否填充 
        gbc.fill = GridBagConstraints.NONE;
        gbc.insets = new Insets(5, 5, 5, 5);
        //加入文字描述
        result.add(new JLabel(getBoldHTML(LABEL_USERNAME)), gbc);
        gbc.gridy++;
        result.add(new JLabel(getBoldHTML(LABEL_PASSWORD)), gbc);

        gbc.gridx++;
        gbc.gridy = 0;
        gbc.fill = GridBagConstraints.HORIZONTAL;
        result.add(fieldUsername, gbc);
        gbc.gridy++;
        result.add(fieldPassword, gbc);

        return result;
    }

    private JComponent layoutText(List<String> lines) {

        assert lines != null;

        JComponent result = new JPanel(new GridLayout(lines.size(), 1));
        for (String line : lines)
            result.add(new JLabel(line));

        result.setBorder(BorderFactory.createEmptyBorder(5, 10, 0, 10));
        return result;
    }

    private String getBoldHTML(String s) {
        // 设置字体的大小粗细
        return "<html><b>" + s + "</b></html>";
    }
}