java jdbc和jframe

Question

当我执行应用程序时，我得到'构建成功'，但jframe没有显示在屏幕上。该应用程序是关于从oracle数据库检索数据和从数据库中找到特定人员（记录）的。 jframe可能有人 的详细信息，例如名字，姓氏等。我可以浏览数据库中的记录。

class Addressbks extends javax.swing.JFrame 
{ 
private JButton browseButton; 

    private JLabel emailLabel; 
    private JTextField emailTextField; 
    private JLabel firstNameLabel; 
    private JTextField firstNameTextField; 
    private JLabel lastNameLabel; 
    private JTextField lastNameTextField; 
    private JLabel idLabel; 
    private JTextField idTextField; 
    private JLabel phoneLabel; 
    private JTextField phoneTextField; 
    private JTextField indexTextField; 


    private JPanel navigatePanel; 
    private JPanel displayPanel; 
    private JPanel queryPanel; 

    private JButton previousButton; 
    private JButton nextButton; 

    private JLabel ofLabel; 
    private JTextField maxTextField; 
    private JTextField queryTextField; 

    private Person currentEntry; 
    private PersonQueries personQueries; 
    private List<Person> results; 
    private int numberOfEntries = 0; 
    private int currentEntryIndex; 
    private JLabel queryLabel; 

    private JButton queryButton; 
    private JButton insertButton; 


    /** 
    * Creates new form Address book 
    */ 
    public Addressbks() { 
     super("The Addressbook"); 
     initComponents();  

    setLayout(new FlowLayout(FlowLayout.CENTER,10,10)); 


    personQueries = new PersonQueries(); 

    navigatePanel = new JPanel(); 
    previousButton = new JButton(); 
    indexTextField = new JTextField(2); 
    ofLabel = new JLabel(); 
    maxTextField = new JTextField(2); 
    nextButton = new JButton(); 

    displayPanel = new JPanel(); 
    idLabel = new JLabel(); 
    idTextField = new JTextField(10); 
    firstNameLabel = new JLabel(); 
    firstNameTextField = new JTextField(10); 
    lastNameLabel = new JLabel(); 
    lastNameTextField = new JTextField(10); 
    emailLabel = new JLabel(); 
    emailTextField = new JTextField(10); 
    phoneLabel = new JLabel(); 
    phoneTextField = new JTextField(10); 



    queryPanel = new JPanel(); 
    queryLabel = new JLabel(); 
    queryTextField =new JTextField(10); 
    queryButton= new JButton(); 
    browseButton = new JButton(); 
    insertButton = new JButton(); 



    navigatePanel.setLayout(new BoxLayout(navigatePanel,BoxLayout.X_AXIS)); 
    previousButton.setText("Previous"); 

    previousButton.setEnabled(false); 

    previousButton.addActionListener(new ActionListener() 
     { 
        @Override 
      public void actionPerformed(ActionEvent e) 
      { 
       previousButtonActionPerformed(e); 
      } 
     }); 
    navigatePanel.add(previousButton); 
    navigatePanel.add(Box.createHorizontalStrut(10)); 

    indexTextField.setHorizontalAlignment(JTextField.CENTER); 

    indexTextField.addActionListener(new ActionListener() 
     { 
        @Override 
      public void actionPerformed(ActionEvent e) 
      { 
       indexTextFieldActionPerformed(e); 
      } 
     }); 

    navigatePanel.add(indexTextField); 
    navigatePanel.add(Box.createHorizontalStrut(10)); 

    ofLabel.setText("of"); 
    navigatePanel.add(ofLabel); 
    navigatePanel.add(Box.createHorizontalStrut(10)); 

    maxTextField.setHorizontalAlignment(JTextField.CENTER); 
    maxTextField.setEditable(false); 
    navigatePanel.add(maxTextField); 
    navigatePanel.add(Box.createHorizontalStrut(10)); 

    nextButton.setText("Next");  
    nextButton.setEnabled(false); 
    nextButton.addActionListener(new ActionListener() 
     { 
        @Override 
      public void actionPerformed(ActionEvent e) 
      { 
       nextButtonActionPerformed(e); 
      } 
     }); 
    navigatePanel.add(nextButton); 
    add(navigatePanel); 

    displayPanel.setLayout(new GridLayout(5,2,4,4)); 

    idLabel.setText("Address ID"); 
    displayPanel.add(idLabel); 


    idTextField.setEditable(false); 
    displayPanel.add(idTextField); 


    firstNameLabel.setText("First Name :"); 
    displayPanel.add(firstNameLabel); 
    displayPanel.add(firstNameTextField); 

     lastNameLabel.setText("Last Name :"); 
    displayPanel.add(lastNameLabel); 
    displayPanel.add(lastNameTextField); 

     emailLabel.setText("Email :"); 
    displayPanel.add(emailLabel); 
    displayPanel.add(emailTextField); 

     phoneLabel.setText("Phone Number :"); 
    displayPanel.add(phoneLabel); 
    displayPanel.add(phoneTextField); 
    add(displayPanel); 

    queryPanel.setLayout(new BoxLayout(queryPanel,BoxLayout.X_AXIS)); 
    queryPanel.setBorder(BorderFactory.createTitledBorder("Find an entry by lastname")); 

    queryLabel.setText("Last Name"); 
    queryPanel.add(Box.createHorizontalStrut(5)); 

    queryPanel.add(queryLabel); 
    queryPanel.add(Box.createHorizontalStrut(10)); 
    queryPanel.add(queryTextField); 
    queryPanel.add(Box.createHorizontalStrut(10)); 

    queryButton.setText("Find"); 
    queryButton.addActionListener(new ActionListener() 
       { 

        @Override 
      public void actionPerformed(ActionEvent e) 
      { 
       queryButtonActionPerformed(e); 
      } 
     }); 
    queryPanel.add(queryButton); 
    queryPanel.add(Box.createHorizontalStrut(5)); 
    add(queryPanel); 

    browseButton.setText("Browse All Entries"); 
    browseButton.addActionListener(new ActionListener() 
       { 

        @Override 
      public void actionPerformed(ActionEvent e) 
      { 
       browseButtonActionPerformed(e); 
      } 
     }); 

    add(browseButton); 

    insertButton.setText("Insert New Entry"); 
    insertButton.addActionListener(new ActionListener() 
       { 

        @Override 
      public void actionPerformed(ActionEvent e) 
      { 
       insertButtonActionPerformed(e); 
      } 
     }); 
    add(insertButton); 

    /* addWindowListener (new WindowAdapter() 
    { 
      @Override 
     public void windowClosing(WindowEvent e) 
       { 
      personQueries.close(); 
      //System.exit(0); 
     } 
    });*/ 

     // setSize(400,400); 
     // setResizable(false); 
    // setLocationRelativeTo(null); 
    // setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
    // setVisible(true); 

    } 
public class Addressbook 
{ 
    /** 
    * @param args the command line arguments 
    */ 

    public static void main(String args[]) throws InterruptedException 
    { 

     try { 
      for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) { 
       if ("Nimbus".equals(info.getName())) { 
        javax.swing.UIManager.setLookAndFeel(info.getClassName()); 
        break; 
       } 
      } 
     } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | javax.swing.UnsupportedLookAndFeelException ex) { 
      java.util.logging.Logger.getLogger(Addressbook.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } 
     //</editor-fold> 

     /* Create and display the form */ 
     /*context: a.setVisible(true) still the jframe is not displayed */ 

     java.awt.EventQueue.invokeLater(new Runnable() { 
        @Override 
      public void run() { 
       JFrame a = new Addressbks(); 
       a.setVisible(true); 

       } 
     }); 
    } 
} 

Answer 1

你还没有为a JFrame的设置大小，尝试添加setSize()方法到你的代码，如：

JFrame a = new Addressbks(); 
a.setSize(400, 400); 
a.setVisible(true); 

或者你可以使用pack()，它就会尺寸框架，使所有其内容达到或超过其首选尺寸。

JFrame a = new Addressbks(); 
a.pack(); 
a.setVisible(true);