java - java Combo Auto Complete 搜索数据在 jdk 9 上运行顺畅,但在 jdk 8 上运行缓慢
问题描述
我的问题是为什么同一个班级在使用 jdk 9 时没有任何延迟,但使用 jdk 8 需要一些时间。使用 jdk 9 及更高版本将解决我的问题,以便自动完成搜索顺利运行,但是我将面临更大的问题是我的报告 jrxml 文件不适用于高于 8 的 jdk。有什么建议可以使此代码在 jdk 8 上顺利运行吗?这是 jdk 9 和 8 的相同代码。在此先感谢我将视频上传到 YouTube 这是一个链接 https://youtu.be/huBr-f-dyCE
import java.awt.event.ActionEvent;
import java.awt.event.FocusAdapter;
import java.awt.event.FocusEvent;
import java.awt.event.FocusListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.beans.PropertyChangeEvent;
import javax.swing.ComboBoxEditor;
import javax.swing.ComboBoxModel;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.text.AttributeSet;
import javax.swing.text.BadLocationException;
import javax.swing.text.JTextComponent;
import javax.swing.text.PlainDocument;
public class ComboAutoComplete1 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 ComboAutoComplete1(final JComboBox comboBox) {
this.comboBox = comboBox;
model = comboBox.getModel();
comboBox.addActionListener((ActionEvent e) -> {
if (!selecting) highlightCompletedText(0);
});
comboBox.addPropertyChangeListener((PropertyChangeEvent e) -> {
if (e.getPropertyName().equals("editor")) configureEditor((ComboBoxEditor) e.getNewValue());
if (e.getPropertyName().equals("model")) model = (ComboBoxModel) e.getNewValue();
});
editorKeyListener = new KeyAdapter() {
@Override
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;
}
}
};
comboBox.getEditor().getEditorComponent().addMouseListener(new MouseAdapter() {
@Override
public void mouseClicked(MouseEvent evt){
}
});
// 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() {
@Override
public void focusGained(FocusEvent e) {
highlightCompletedText(0);
}
@Override
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, String str) {
// has to be editable
comboBox.setEditable(true);
// change the editor's document
new ComboAutoComplete1(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);
}
}
@Override
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);
}
}
@Override
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();
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(() -> {
createAndShowGUI();
});
}
}
解决方案
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