如何在 Java 中验证 JTable 是否有空单元格?
awtjavaobject oriented programmingprogrammingswing
JTable 是 JComponent 类的子类，用于显示复杂的数据结构。JTable 可以遵循 Model View Controller (MVC) 设计模式，以 行和列 显示数据。JTable 将生成 TableModelListener、TableColumnModelListener、ListSelectionListener、CellEditorListener 和 RowSorterListener 接口。
我们可以通过实现 JTable 类的 getValueAt() 方法来验证 JTable 单元格是否为空。如果我们点击"单击此处"按钮，它将生成一个动作事件并向用户显示一个弹出消息，如"字段为空"。
示例
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.table.*;
public class JTableEmptyValidateTest extends JFrame {
private JPanel panel;
private JTable table;
private JButton button;
String[] columnNames = new String[] {"Student 1", "Student 2"};
String[][] dataValues = new String[][] {{"95", "100"}, {"", "85"}, {"80", "100"}};
public JTableEmptyValidateTest() {
setTitle("Empty Validation Table");
panel = new JPanel();
table = new JTable();
TableModel model = new myTableModel();
table.setModel(model);
panel.add(new JScrollPane(table));
button = new JButton("Click Here");
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent event) {
if(validCheck()) {
JOptionPane.showMessageDialog(null,"Field is filled up");
} else {
JOptionPane.showMessageDialog(null, "Field is empty");
}
}
});
add(panel, BorderLayout.CENTER);
add(button, BorderLayout.SOUTH);
setSize(470, 300);
setDefaultCloseOperation(EXIT_ON_CLOSE);
setLocationRelativeTo(null);
setVisible(true);
}
public boolean validCheck() {
if(table.getCellEditor()!= null) {
table.getCellEditor().stopCellEditing();
}
for(int i=0; i < table.getRowCount(); i++) {
for(int j=0; j < table.getColumnCount(); j++) {
String value = table.getValueAt(i,j).toString();
if(value.trim().length() == 0) {
return false;
}
}
}
return true;
}
class myTableModel extends DefaultTableModel {
myTableModel() {
super(dataValues, columnNames);
}
public boolean isCellEditable(int row, int cols) {
return true;
}
}
public static void main(String args[]) {
new JTableEmptyValidateTest();
}
}
输出
