Java Swing：从TableModel捕获异常
我有一个TableModel，如果用户输入无效值，它可能会在其Java Swing：从TableModel捕获异常,java,swing,exception-handling,tablemodel,Java,Swing,Exception Handling,Tablemodel,我有一个TableModel，如果用户输入无效值，它可能会在其setValueAt方法上引发异常： public class MyTableModel extends AbstractTableModel { public void setValueAt(Object value, int rowIndex, int columnIndex) { String valueStr = (String) value; // some basic failure
setValueAtpublic class MyTableModel extends AbstractTableModel {
public void setValueAt(Object value, int rowIndex, int columnIndex) {
String valueStr = (String) value;
// some basic failure state
if(valueStr.length()>5) {
throw new ValidationException("Value should have up to 5 characters");
}
this.currentValue = valueStr;
}
}
问题是：另一个类如何捕获此异常？它可能会显示弹出消息，或更新状态栏，或将单元格涂成红色。无论我选择做什么，我不认为
TableModel但我不确定是否有更合适的方法来处理这种情况，比如某种异常侦听器。第一种选择是使用：
但我不确定是否有更合适的方法来处理这种情况，比如某种异常侦听器。第一种选择是使用：
但我不确定是否有更合适的方法来处理这种情况，比如某种异常侦听器。第一种选择是使用：
但我不确定是否有更合适的方法来处理这种情况，比如某种异常侦听器。您可能正在使用JTable编辑单元格，以便可以使用自定义编辑器：
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
public class TableFiveCharacterEditor extends DefaultCellEditor
{
private long lastTime = System.currentTimeMillis();
public TableFiveCharacterEditor()
{
super( new JTextField() );
}
public boolean stopCellEditing()
{
JTable table = (JTable)getComponent().getParent();
try
{
String editingValue = (String)getCellEditorValue();
if(editingValue.length() != 5)
{
JTextField textField = (JTextField)getComponent();
textField.setBorder(new LineBorder(Color.red));
textField.selectAll();
textField.requestFocusInWindow();
JOptionPane.showMessageDialog(
table,
"Please enter string with 5 letters.",
"Alert!",JOptionPane.ERROR_MESSAGE);
return false;
}
}
catch(ClassCastException exception)
{
return false;
}
return super.stopCellEditing();
}
public Component getTableCellEditorComponent(
JTable table, Object value, boolean isSelected, int row, int column)
{
Component c = super.getTableCellEditorComponent(
table, value, isSelected, row, column);
((JComponent)c).setBorder(new LineBorder(Color.black));
return c;
}
private static void createAndShowUI()
{
JTable table = new JTable(5, 5);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane(table);
// Use a custom editor
TableCellEditor fce = new TableFiveCharacterEditor();
table.setDefaultEditor(Object.class, fce);
JFrame frame = new JFrame("Table Five Character Editor");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( scrollPane );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
假设您正在使用JTable编辑单元格，以便可以使用自定义编辑器：
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
public class TableFiveCharacterEditor extends DefaultCellEditor
{
private long lastTime = System.currentTimeMillis();
public TableFiveCharacterEditor()
{
super( new JTextField() );
}
public boolean stopCellEditing()
{
JTable table = (JTable)getComponent().getParent();
try
{
String editingValue = (String)getCellEditorValue();
if(editingValue.length() != 5)
{
JTextField textField = (JTextField)getComponent();
textField.setBorder(new LineBorder(Color.red));
textField.selectAll();
textField.requestFocusInWindow();
JOptionPane.showMessageDialog(
table,
"Please enter string with 5 letters.",
"Alert!",JOptionPane.ERROR_MESSAGE);
return false;
}
}
catch(ClassCastException exception)
{
return false;
}
return super.stopCellEditing();
}
public Component getTableCellEditorComponent(
JTable table, Object value, boolean isSelected, int row, int column)
{
Component c = super.getTableCellEditorComponent(
table, value, isSelected, row, column);
((JComponent)c).setBorder(new LineBorder(Color.black));
return c;
}
private static void createAndShowUI()
{
JTable table = new JTable(5, 5);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane(table);
// Use a custom editor
TableCellEditor fce = new TableFiveCharacterEditor();
table.setDefaultEditor(Object.class, fce);
JFrame frame = new JFrame("Table Five Character Editor");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( scrollPane );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
假设您正在使用JTable编辑单元格，以便可以使用自定义编辑器：
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
public class TableFiveCharacterEditor extends DefaultCellEditor
{
private long lastTime = System.currentTimeMillis();
public TableFiveCharacterEditor()
{
super( new JTextField() );
}
public boolean stopCellEditing()
{
JTable table = (JTable)getComponent().getParent();
try
{
String editingValue = (String)getCellEditorValue();
if(editingValue.length() != 5)
{
JTextField textField = (JTextField)getComponent();
textField.setBorder(new LineBorder(Color.red));
textField.selectAll();
textField.requestFocusInWindow();
JOptionPane.showMessageDialog(
table,
"Please enter string with 5 letters.",
"Alert!",JOptionPane.ERROR_MESSAGE);
return false;
}
}
catch(ClassCastException exception)
{
return false;
}
return super.stopCellEditing();
}
public Component getTableCellEditorComponent(
JTable table, Object value, boolean isSelected, int row, int column)
{
Component c = super.getTableCellEditorComponent(
table, value, isSelected, row, column);
((JComponent)c).setBorder(new LineBorder(Color.black));
return c;
}
private static void createAndShowUI()
{
JTable table = new JTable(5, 5);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane(table);
// Use a custom editor
TableCellEditor fce = new TableFiveCharacterEditor();
table.setDefaultEditor(Object.class, fce);
JFrame frame = new JFrame("Table Five Character Editor");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( scrollPane );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
假设您正在使用JTable编辑单元格，以便可以使用自定义编辑器：
import java.awt.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.table.*;
public class TableFiveCharacterEditor extends DefaultCellEditor
{
private long lastTime = System.currentTimeMillis();
public TableFiveCharacterEditor()
{
super( new JTextField() );
}
public boolean stopCellEditing()
{
JTable table = (JTable)getComponent().getParent();
try
{
String editingValue = (String)getCellEditorValue();
if(editingValue.length() != 5)
{
JTextField textField = (JTextField)getComponent();
textField.setBorder(new LineBorder(Color.red));
textField.selectAll();
textField.requestFocusInWindow();
JOptionPane.showMessageDialog(
table,
"Please enter string with 5 letters.",
"Alert!",JOptionPane.ERROR_MESSAGE);
return false;
}
}
catch(ClassCastException exception)
{
return false;
}
return super.stopCellEditing();
}
public Component getTableCellEditorComponent(
JTable table, Object value, boolean isSelected, int row, int column)
{
Component c = super.getTableCellEditorComponent(
table, value, isSelected, row, column);
((JComponent)c).setBorder(new LineBorder(Color.black));
return c;
}
private static void createAndShowUI()
{
JTable table = new JTable(5, 5);
table.setPreferredScrollableViewportSize(table.getPreferredSize());
JScrollPane scrollPane = new JScrollPane(table);
// Use a custom editor
TableCellEditor fce = new TableFiveCharacterEditor();
table.setDefaultEditor(Object.class, fce);
JFrame frame = new JFrame("Table Five Character Editor");
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.add( scrollPane );
frame.pack();
frame.setLocationByPlatform( true );
frame.setVisible( true );
}
public static void main(String[] args)
{
EventQueue.invokeLater(new Runnable()
{
public void run()
{
createAndShowUI();
}
});
}
}
一份令人信服的证词可能被判有罪。您还忘了提到没有理由扩展JFrame。转到我关于旧例子的观点…；）我有太多的谎言，我忘记了更新他们。代码已更新。可能会发现一份令人信服的证明材料。@MadProgrammer，被指控有罪。您还忘了提到没有理由扩展JFrame。转到我关于旧例子的观点…；）我有太多的谎言，我忘记了更新他们。代码已更新。可能会发现一份令人信服的证明材料。@MadProgrammer，被指控有罪。您还忘了提到没有理由扩展JFrame。转到我关于旧例子的观点…；）我有太多的谎言，我忘记了更新他们。代码已更新。可能会发现一份令人信服的证明材料。@MadProgrammer，被指控有罪。您还忘了提到没有理由扩展JFrame。转到我关于旧例子的观点…；）我有太多的谎言，我忘记了更新他们。代码已更新。