JTable行选择和数据检索

Question

这是我第一次创建一个程序，该程序将连接到数据库以获取数据并将其放入JTable。

现在的问题是我想从上表中选择一行并将结果显示在指定的JTextFields中。

我尝试了谷歌提供的许多搜索结果，但我仍然无法弄清楚如何去做。

这里是该程序的完整源代码。

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.*; 
import java.sql.*; 
import javax.swing.table.*; 

public class MalayaUniversityEnrollment extends JFrame //implements ActionListener 
{ 
JLabel header = new JLabel ("MALAYA UNIVERSITY ENROLLMENT SYSTEM"); 

JLabel searchHeader = new JLabel ("SEARCH A STUDENT "); 
JLabel infoHeader = new JLabel ("STUDENT INFORMATION"); 

JButton addButton = new JButton ("ENROLL STUDENT"); 
JButton editButton = new JButton ("EDIT INFO"); 
JButton deleteButton = new JButton ("DELETE STUDENT"); 
JButton searchButton = new JButton ("SEARCH IT!"); 
JButton clearButton = new JButton ("CLEAR ALL FIELDS"); 

JTextField studentIDField = new JTextField(); 
JTextField lastNameField = new JTextField(); 
JTextField firstNameField = new JTextField(); 
JTextField middleInitialField = new JTextField(); 
JTextField CYSField = new JTextField(); 
JTextField tuitionField = new JTextField(); 
JTextField statusField = new JTextField(); 
JTextField searchField = new JTextField(); 

JLabel studentIDLabel = new JLabel ("Student ID Number: "); 
JLabel lastNameLabel = new JLabel ("Last Name: "); 
JLabel firstNameLabel = new JLabel ("First Name: "); 
JLabel middleInitialLabel = new JLabel ("Middle Initial: "); 
JLabel CYSLabel = new JLabel ("CYS: "); 
JLabel tuitionLabel = new JLabel ("Semestral Tuition: "); 
JLabel statusLabel = new JLabel ("Status: "); 
private final JTable table = new JTable(); 
private final JScrollPane scrollPane = new JScrollPane(); 

String SID =""; 
String lastName=""; 
String firstName=""; 
String middleInitial=""; 
String CYS=""; 
Double semestralTuition=0.00; 
String studentStatus=""; 

String[] headers = {"Student ID", "Last Name", "First Name", "Middle Initial","CYS", "Semestral Tuition", "Status"}; 

DefaultTableModel model = new DefaultTableModel(); 

public MalayaUniversityEnrollment() 
{ 
    super ("Malaya University [Enrollment]"); 

    Container c = getContentPane(); 
    c.setLayout(null); 

    c.add(header); 
    header.setBounds(290,20,1000,35); 
    header.setFont(new Font("Tahoma", Font.PLAIN, 35)); 

    c.add(addButton); 
    c.add(editButton); 
    c.add(deleteButton); 
    c.add(searchButton); 
    c.add(clearButton); 

    c.add(searchHeader); 
    c.add(infoHeader); 

    c.add(studentIDField); 
    c.add(lastNameField); 
    c.add(firstNameField); 
    c.add(middleInitialField); 
    c.add(CYSField); 
    c.add(tuitionField); 
    c.add(statusField); 
    c.add(searchField); 

    c.add(studentIDLabel); 
    c.add(lastNameLabel); 
    c.add(firstNameLabel); 
    c.add(middleInitialLabel); 
    c.add(CYSLabel); 
    c.add(tuitionLabel); 
    c.add(statusLabel); 

    studentIDLabel.setBounds(50,575,100,30); 
    lastNameLabel.setBounds(50,615,100,30); 
    firstNameLabel.setBounds(50,660,100,30); 
    middleInitialLabel.setBounds(50,700,100,30); 

    studentIDField.setBounds(175,575,200,30); 
    lastNameField.setBounds(175,615,200,30); 
    firstNameField.setBounds(175,660,200,30); 
    middleInitialField.setBounds(175,700,200,30); 

    CYSLabel.setBounds(450,575,100,30); 
    tuitionLabel.setBounds(450,615,100,30); 
    statusLabel.setBounds(450,660,100,30); 

    CYSField.setBounds(575,575,200,30); 
    tuitionField.setBounds(575,615,200,30); 
    statusField.setBounds(575,660,200,30); 

    infoHeader.setBounds(270,525,500,50); 
    infoHeader.setFont(new Font("Tahoma", Font.PLAIN, 30)); 

    searchField.setBounds(885,638,300,30); 
    searchHeader.setBounds(895,575,300,50); 
    searchHeader.setFont(new Font("Tahoma", Font.PLAIN, 30)); 

    searchButton.setBounds(938,688,200,23); 

    addButton.setBounds(450,700,146,23); 
    editButton.setBounds(630,700,146,23); 
    deleteButton.setBounds(450,733,146,23); 
    clearButton.setBounds(630,733,146,23); 

    studentIDField.setHorizontalAlignment(JTextField.CENTER); 
    lastNameField.setHorizontalAlignment(JTextField.CENTER); 
    firstNameField.setHorizontalAlignment(JTextField.CENTER); 
    middleInitialField.setHorizontalAlignment(JTextField.CENTER); 
    CYSField.setHorizontalAlignment(JTextField.CENTER); 
    tuitionField.setHorizontalAlignment(JTextField.CENTER); 
    statusField.setHorizontalAlignment(JTextField.CENTER); 
    searchField.setHorizontalAlignment(JTextField.CENTER); 


    scrollPane.setBounds(50, 88, 1190, 412); 

    getContentPane().add(scrollPane); 
    table.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); 
    table.setShowGrid(true); 

    model.setColumnIdentifiers(headers); 
    table.setModel(model); 
    scrollPane.setViewportView(table); 

    JTableHeader header = table.getTableHeader(); 

    header.setDefaultRenderer(new HeaderRenderer(table)); 

    table.getTableHeader().setReorderingAllowed(false); 



    setSize(1300,825); 
    setVisible(true); 
    setDefaultCloseOperation(EXIT_ON_CLOSE); 
    setLocationRelativeTo(null); 

    for (int y=0; y<7; y++) 
    { 
     DefaultTableCellRenderer centerRenderer = new DefaultTableCellRenderer(); 
     centerRenderer.setHorizontalAlignment(JLabel.CENTER); 
     table.getColumnModel().getColumn(y).setCellRenderer(centerRenderer); 
    } 


    RetrieveData(); 
} 

private static class HeaderRenderer implements TableCellRenderer 
    { 

     DefaultTableCellRenderer renderer; 

     public HeaderRenderer(JTable table) 
     { 
      renderer = (DefaultTableCellRenderer) 
      table.getTableHeader().getDefaultRenderer(); 
      renderer.setHorizontalAlignment(JLabel.CENTER); 
     } 


     public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected,boolean hasFocus, int row, int col) 

     { 
      return renderer.getTableCellRendererComponent(
      table, value, isSelected, hasFocus, row, col); 
     } 
} 

public void RetrieveData() 
{ 
    try 
    { 
     int x=0; 
     String query = "Select * FROM `2013-2014 enrollment`"; 
     DatabaseConfig a = new DatabaseConfig(); 
     ResultSet rs = a.showR(query); 

     while(rs.next()) 
     { 
      SID = rs.getString("Student_ID"); 
      lastName = rs.getString("Last_Name"); 
      firstName = rs.getString("First_Name"); 
      middleInitial = rs.getString("Middle_Initial"); 
      CYS = rs.getString("CYS"); 
      semestralTuition = rs.getDouble("Semestral_Tuition"); 
      studentStatus = rs.getString("Status"); 

      model.addRow(new Object[]{SID,lastName,firstName,middleInitial,CYS,semestralTuition,studentStatus}); 


      x++; 

      System.out.println(rs.getString(1) + " " + rs.getString(2) + " " + rs.getString(3) + " " + rs.getString(4) + " " + rs.getString(5) + " " + rs.getString(6) + " " + rs.getString(7)); 
     } 



    } 
    catch (Exception e) 
    { 
     JOptionPane.showMessageDialog(null, "There is an error."); 
    } 
} 

public static void main (String[] args) 
{ 
    try 
    { 
     UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName()); 
    } 

    catch (Exception exe) 
    { 
     System.out.println("ERROR: Could not Load System UI."); 
    } 


    new MalayaUniversityEnrollment(); 

} 
} 

我想知道如何去做。任何答复/答案将不胜感激。提前致谢。

Answer 1

阅读有关How to Write a List Selection Listener的Swing教程的部分。

当选择更改时，您将获得当前选定的行。然后，您可以使用每个文本字段的table.getValueAt（...）方法在文本字段中显示数据。

另外，请勿使用setBounds（）。 Swing旨在与布局管理器一起使用。该教程还有一个布局管理器部分，您可以阅读以获取更多信息。

Answer 2

我没有看到您添加了任何听众来听选择行更改。不知道，你在看什么谷歌搜索。示例代码（值可以增强对其他值/清除时行未被选择）

table.getSelectionModel().addListSelectionListener(new ListSelectionListener() { 

     @Override 
     public void valueChanged(ListSelectionEvent e) { 
      int selectedRow = table.getSelectedRow(); 
      String sid = (String)table.getValueAt(selectedRow, 0); 
      studentIDField.setText(sid); 


     } 
    });