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。

  1 package Com.SwingTest;
  2 
  3 
  4 import java.awt.BorderLayout;
  5 import java.awt.GridBagConstraints;
  6 import java.awt.GridBagLayout;
  7 import java.awt.GridLayout;
  8 import java.awt.Insets;
  9 import java.awt.event.ActionEvent;
 10 import java.util.Arrays;
 11 import java.util.List;
 12 
 13 import javax.swing.AbstractAction;
 14 import javax.swing.Action;
 15 import javax.swing.BorderFactory;
 16 import javax.swing.JButton;
 17 import javax.swing.JComponent;
 18 import javax.swing.JFrame;
 19 import javax.swing.JLabel;
 20 import javax.swing.JOptionPane;
 21 import javax.swing.JPanel;
 22 import javax.swing.JPasswordField;
 23 import javax.swing.JTextField;
 24 import javax.swing.SwingUtilities;
 25 import javax.swing.UIManager;
 26 
 27 
 28 /**
 29 * @author Administrator
 30 *
 31 */
 32 public class SwingText_11 extends JPanel {
 33 
 34     private static final String LABEL_USERNAME = "用户账号：";
 35     private static final String LABEL_PASSWORD = "用户密码：";
 36 
 37     private static final String LABEL_OK = "确定";
 38     private static final String LABEL_Cancel = "取消";
 39 
 40     private static final int FIELD_COLS = 20;
 41 
 42     private JTextField fieldUsername;
 43     private JPasswordField fieldPassword;
 44 
 45     private Action actionOK;
 46     private Action actionCancel;
 47     
 48     
 49     public static void main(String[] args) {
 50 
 51         SwingUtilities.invokeLater(new Runnable() {
 52             @Override
 53             public void run() {
 54                 try {
 55                     UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
 56                 } catch (Exception e) {
 57                     e.printStackTrace();
 58                 }
 59                 JFrame test = new JFrame("欢迎进入本系统");
 60                 test.setContentPane(new SwingText_11());
 61                 test.pack();
 62                 test.setResizable(false);
 63                 test.setLocationRelativeTo(null);
 64                 test.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
 65                 test.setVisible(true);
 66             }
 67         });
 68     }
 69 
 70 
 71 
 72     SwingText_11() {
 73 
 74         super(new BorderLayout(5, 5));
 75         assert SwingUtilities.isEventDispatchThread();
 76         // 文本框
 77         fieldUsername = new JTextField(FIELD_COLS);
 78         // 密码框
 79         fieldPassword = new JPasswordField(FIELD_COLS);
 80 
 81         actionOK = new AbstractAction(LABEL_OK) {
 82             @Override
 83             public void actionPerformed(ActionEvent e) {
 84                 // @TODO to be implemented. 实现确认按钮的操作
 85                 //TODO
 86                 String text = fieldUsername.getText();
 87                 if (text.isEmpty()) {
 88                     JOptionPane.showMessageDialog(null, "用户名不能为空！", "提示", JOptionPane.ERROR_MESSAGE);
 89                     return;
 90                 }
 91                 
 92                 JOptionPane.showMessageDialog(null, "这是一个假登录"+text, "提示", JOptionPane.ERROR_MESSAGE); 
 93             }
 94         };
 95 
 96         actionCancel = new AbstractAction(LABEL_Cancel) {
 97             @Override
 98             public void actionPerformed(ActionEvent e) {
 99                 // @TODO to be implemented. 实现取消按钮的操作
100                 //退出程序
101                 System.exit(0);
102             }
103         };
104         //  BorderLayout.NORTH 这是指定向北浮动
105         add(layoutText(Arrays.asList( "第一行文字", "第二行文字", "第三行文字")), BorderLayout.NORTH);
106         add(layoutFields(), BorderLayout.CENTER);
107         add(layoutControl(), BorderLayout.SOUTH);
108 
109         setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5));
110     }
111 
112     private JComponent layoutControl() {
113         // 控件布局  
114         JComponent result = new JPanel();
115         // 这里是确认 和 取消的按钮
116         result.add(new JButton(actionOK));
117         result.add(new JButton(actionCancel));
118 
119         return result;
120     }
121 
122     private JComponent layoutFields() {
123         // 布局位置
124         JComponent result = new JPanel(new GridBagLayout());
125         GridBagConstraints gbc = new GridBagConstraints();
126 
127         gbc.gridx = 0;
128         gbc.gridy = 0;
129         //固定 向西
130         gbc.anchor = GridBagConstraints.WEST;
131         //是否填充 
132         gbc.fill = GridBagConstraints.NONE;
133         gbc.insets = new Insets(5, 5, 5, 5);
134         //加入文字描述
135         result.add(new JLabel(getBoldHTML(LABEL_USERNAME)), gbc);
136         gbc.gridy++;
137         result.add(new JLabel(getBoldHTML(LABEL_PASSWORD)), gbc);
138 
139         gbc.gridx++;
140         gbc.gridy = 0;
141         gbc.fill = GridBagConstraints.HORIZONTAL;
142         result.add(fieldUsername, gbc);
143         gbc.gridy++;
144         result.add(fieldPassword, gbc);
145 
146         return result;
147     }
148 
149     private JComponent layoutText(List<String> lines) {
150 
151         assert lines != null;
152 
153         JComponent result = new JPanel(new GridLayout(lines.size(), 1));
154         for (String line : lines)
155             result.add(new JLabel(line));
156 
157         result.setBorder(BorderFactory.createEmptyBorder(5, 10, 0, 10));
158         return result;
159     }
160 
161     private String getBoldHTML(String s) {
162         // 设置字体的大小粗细
163         return "<html><b>" + s + "</b></html>";
164     }
165 }