Использование JComboBox в качестве поиска

Question

Я хочу знать, как получить JComboBox для автоматического указания элементов при вводе в поле со списком. Например, если я загрузил JComboBox с этими именами, используя MySQL, [Amila, Nimila, Nikila, Sunil], и когда я наберу «N» внутри Combo Box, он выйдет из списка, показывая Nimila & Nikila as предложения. И я пытаюсь сделать это на NetBeans. Благодарю.

Answer 1

Возможный дубликат: JComboBox autocomplete. Однако, если вы хотите использовать решение на основе чистого свинга, следуйте этой статье. это весьма всеобъемлющий

http://www.orbital-computer.de/JComboBox/

Если вы хотите, быстрое и простое решение, просто добавить этот класс в проект;

import java.awt.event.*; 
import java.beans.PropertyChangeEvent; 
import java.beans.PropertyChangeListener; 
import javax.swing.*; 
import javax.swing.text.*; 

/* This work is hereby released into the Public Domain. 
* To view a copy of the public domain dedication, visit 
* http://creativecommons.org/licenses/publicdomain/ 
*/ 
public class AutoCompletion extends PlainDocument { 
JComboBox comboBox; 
ComboBoxModel model; 
JTextComponent editor; 
// flag to indicate if setSelectedItem has been called 
// subsequent calls to remove/insertString should be ignored 
boolean selecting=false; 
boolean hidePopupOnFocusLoss; 
boolean hitBackspace=false; 
boolean hitBackspaceOnSelection; 

KeyListener editorKeyListener; 
FocusListener editorFocusListener; 

public AutoCompletion(final JComboBox comboBox) { 
    this.comboBox = comboBox; 
    model = comboBox.getModel(); 
    comboBox.addActionListener(new ActionListener() { 
     public void actionPerformed(ActionEvent e) { 
      if (!selecting) highlightCompletedText(0); 
     } 
    }); 
    comboBox.addPropertyChangeListener(new PropertyChangeListener() { 
     public void propertyChange(PropertyChangeEvent e) { 
      if (e.getPropertyName().equals("editor")) configureEditor((ComboBoxEditor) e.getNewValue()); 
      if (e.getPropertyName().equals("model")) model = (ComboBoxModel) e.getNewValue(); 
     } 
    }); 
    editorKeyListener = new KeyAdapter() { 
     public void keyPressed(KeyEvent e) { 
      if (comboBox.isDisplayable()) comboBox.setPopupVisible(true); 
      hitBackspace=false; 
      switch (e.getKeyCode()) { 
       // determine if the pressed key is backspace (needed by the remove method) 
       case KeyEvent.VK_BACK_SPACE : hitBackspace=true; 
       hitBackspaceOnSelection=editor.getSelectionStart()!=editor.getSelectionEnd(); 
       break; 
       // ignore delete key 
       case KeyEvent.VK_DELETE : e.consume(); 
       comboBox.getToolkit().beep(); 
       break; 
      } 
     } 
    }; 
    // Bug 5100422 on Java 1.5: Editable JComboBox won't hide popup when tabbing out 
    hidePopupOnFocusLoss=System.getProperty("java.version").startsWith("1.5"); 
    // Highlight whole text when gaining focus 
    editorFocusListener = new FocusAdapter() { 
     public void focusGained(FocusEvent e) { 
      highlightCompletedText(0); 
     } 
     public void focusLost(FocusEvent e) { 
      // Workaround for Bug 5100422 - Hide Popup on focus loss 
      if (hidePopupOnFocusLoss) comboBox.setPopupVisible(false); 
     } 
    }; 
    configureEditor(comboBox.getEditor()); 
    // Handle initially selected object 
    Object selected = comboBox.getSelectedItem(); 
    if (selected!=null) setText(selected.toString()); 
    highlightCompletedText(0); 
} 

public static void enable(JComboBox comboBox) { 
    // has to be editable 
    comboBox.setEditable(true); 
    // change the editor's document 
    new AutoCompletion(comboBox); 
} 

void configureEditor(ComboBoxEditor newEditor) { 
    if (editor != null) { 
     editor.removeKeyListener(editorKeyListener); 
     editor.removeFocusListener(editorFocusListener); 
    } 

    if (newEditor != null) { 
     editor = (JTextComponent) newEditor.getEditorComponent(); 
     editor.addKeyListener(editorKeyListener); 
     editor.addFocusListener(editorFocusListener); 
     editor.setDocument(this); 
    } 
} 

public void remove(int offs, int len) throws BadLocationException { 
    // return immediately when selecting an item 
    if (selecting) return; 
    if (hitBackspace) { 
     // user hit backspace => move the selection backwards 
     // old item keeps being selected 
     if (offs>0) { 
      if (hitBackspaceOnSelection) offs--; 
     } else { 
      // User hit backspace with the cursor positioned on the start => beep 
      comboBox.getToolkit().beep(); // when available use: UIManager.getLookAndFeel().provideErrorFeedback(comboBox); 
     } 
     highlightCompletedText(offs); 
    } else { 
     super.remove(offs, len); 
    } 
} 

public void insertString(int offs, String str, AttributeSet a) throws BadLocationException { 
    // return immediately when selecting an item 
    if (selecting) return; 
    // insert the string into the document 
    super.insertString(offs, str, a); 
    // lookup and select a matching item 
    Object item = lookupItem(getText(0, getLength())); 
    if (item != null) { 
     setSelectedItem(item); 
    } else { 
     // keep old item selected if there is no match 
     item = comboBox.getSelectedItem(); 
     // imitate no insert (later on offs will be incremented by str.length(): selection won't move forward) 
     offs = offs-str.length(); 
     // provide feedback to the user that his input has been received but can not be accepted 
     comboBox.getToolkit().beep(); // when available use: UIManager.getLookAndFeel().provideErrorFeedback(comboBox); 
    } 
    setText(item.toString()); 
    // select the completed part 
    highlightCompletedText(offs+str.length()); 
} 

private void setText(String text) { 
    try { 
     // remove all text and insert the completed string 
     super.remove(0, getLength()); 
     super.insertString(0, text, null); 
    } catch (BadLocationException e) { 
     throw new RuntimeException(e.toString()); 
    } 
} 

private void highlightCompletedText(int start) { 
    editor.setCaretPosition(getLength()); 
    editor.moveCaretPosition(start); 
} 

private void setSelectedItem(Object item) { 
    selecting = true; 
    model.setSelectedItem(item); 
    selecting = false; 
} 

private Object lookupItem(String pattern) { 
    Object selectedItem = model.getSelectedItem(); 
    // only search for a different item if the currently selected does not match 
    if (selectedItem != null && startsWithIgnoreCase(selectedItem.toString(), pattern)) { 
     return selectedItem; 
    } else { 
     // iterate over all items 
     for (int i=0, n=model.getSize(); i < n; i++) { 
      Object currentItem = model.getElementAt(i); 
      // current item starts with the pattern? 
      if (currentItem != null && startsWithIgnoreCase(currentItem.toString(), pattern)) { 
       return currentItem; 
      } 
     } 
    } 
    // no item starts with the pattern => return null 
    return null; 
} 

// checks if str1 starts with str2 - ignores case 
private boolean startsWithIgnoreCase(String str1, String str2) { 
    return str1.toUpperCase().startsWith(str2.toUpperCase()); 
} 

private static void createAndShowGUI() { 
    // the combo box (add/modify items if you like to) 
    final JComboBox comboBox = new JComboBox(new Object[] {"Ester", "Jordi", "Jordina", "Jorge", "Sergi"}); 
    enable(comboBox); 

    // create and show a window containing the combo box 
    final JFrame frame = new JFrame(); 
    frame.setDefaultCloseOperation(3); 
    frame.getContentPane().add(comboBox); 
    frame.pack(); frame.setVisible(true); 
} 


public static void main(String[] args) { 
    javax.swing.SwingUtilities.invokeLater(new Runnable() { 
     public void run() { 
      createAndShowGUI(); 
     } 
    }); 
} 
} 

А затем, чтобы добавить функцию автозаполнения в JComboBox, просто позвоните;

AutoCompletion.enable(yourComboBox);