IDEA 插件开发：Swing 图形界面设计指南

2. JDialog

对话框通常依附于主窗口存在。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class DialogTest {
    public static void main(String[] args) {
        JFrame frame = new JFrame("测试 Dialog");
        // 创建模式对话框
        JDialog d1 = new JDialog(frame, "模式对话框", true);
        // 设置 Dialog 位置和大小
        d1.setBounds(20, 30, 300, 200);
        
        JButton b1 = new JButton("打开模式对话框");
        b1.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                d1.setVisible(true);
            }
        });
        
        frame.add(b1, BorderLayout.NORTH);
        frame.pack();
        frame.setVisible(true);
    }
}

3. MessageDialog

这是简化版的弹出确认框，注意这些 Dialog 默认都是模态化的。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class MessageDialogTest {
    JFrame jf = new JFrame("测试消息对话框");
    JTextArea jta = new JTextArea(6, 30);
    JButton btn = new JButton(new AbstractAction("弹出消息对话框") {
        @Override
        public void actionPerformed(ActionEvent e) {
            String text = jta.getText();
            // 参数说明：int messageType 指定类型（错误、警告、问题等）
            // JOptionPane.showMessageDialog(jf, text, "消息对话框", JOptionPane.WARNING_MESSAGE);
            JOptionPane.showMessageDialog(jf, text, "消息对话框", JOptionPane.WARNING_MESSAGE, 
                new ImageIcon("E:\\GUISwing\\img\\component\\female.png"));
        }
    });

    public void init() {
        jf.add(jta);
        jf.add(btn, BorderLayout.SOUTH);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new MessageDialogTest().init();
    }
}

4. 为容器添加工具栏

Frame 菜单

菜单分为嵌入 Frame 中的主菜单和右键上下文菜单两种。

import javax.swing.*;
import java.awt.*;

public class SimpleMenu {
    private JFrame frame = new JFrame("测试菜单相关组件");
    private JMenuBar menuBar = new JMenuBar();
    private JMenu fileMenu = new JMenu("文件");
    private JMenu editMenu = new JMenu("编辑");
    private JMenuItem copy = new JMenuItem("复制");
    private JMenuItem paste = new JMenuItem("粘贴");

    public void init() {
        editMenu.add(copy);
        editMenu.add(paste);
        menuBar.add(fileMenu);
        menuBar.add(editMenu);
        frame.setJMenuBar(menuBar);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        new SimpleMenu().init();
    }
}

Toolbar 工具栏

工具栏支持拖动停靠。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class JToolBarTest {
    JFrame jf = new JFrame("测试工具条");
    JTextArea jta = new JTextArea(6, 35);
    JToolBar jToolBar = new JToolBar("播放工具条", SwingConstants.HORIZONTAL);

    Action pre = new AbstractAction("上一曲", new ImageIcon("E:\\GUISwing\\img\\component\\上一曲 16.png")) {
        @Override
        public void actionPerformed(ActionEvent e) {
            jta.append("上一曲.\n");
        }
    };

    public void init() {
        JButton preBtn = new JButton(pre);
        jToolBar.add(preBtn);
        jToolBar.addSeparator();
        jToolBar.setFloatable(true); // 允许拖动
        jf.add(jToolBar, BorderLayout.NORTH);
        JScrollPane jScrollPane = new JScrollPane(jta);
        jf.add(jScrollPane);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new JToolBarTest().init();
    }
}

5. 特殊容器

JSplitPane - 可调整大小的面板

用于分割两个区域，用户可拖动分隔条调整比例。

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

@Data
@AllArgsConstructor
class Book {
    private String name;
    private String desc;
}

public class SplitPaneTest {
    Book[] books = {
        new Book("java 自学宝典", "国内关于 Java 编程最全面的图书，看得懂，学得会"),
        new Book("轻量级的 JAVAEE 企业应用实战", "SSM 整合开发的经典图书，值得拥有")
    };
    JFrame jf = new JFrame("测试 JSplitPane");
    JList<Book> bookJList = new JList<>(books);
    JLabel bookCover = new JLabel();
    JTextArea bookDesc = new JTextArea();

    public void init() {
        bookJList.setPreferredSize(new Dimension(150, 400));
        bookCover.setPreferredSize(new Dimension(220, 270));
        bookDesc.setPreferredSize(new Dimension(220, 130));

        bookJList.addListSelectionListener(e -> {
            Book book = bookJList.getSelectedValue();
            if (book != null) {
                bookDesc.setText(book.getDesc());
            }
        });

        JSplitPane left = new JSplitPane(JSplitPane.VERTICAL_SPLIT, bookCover, new JScrollPane(bookDesc));
        left.setOneTouchExpandable(true);

        JSplitPane hole = new JSplitPane(JSplitPane.HORIZONTAL_SPLIT, left, bookJList);
        hole.setContinuousLayout(true);
        hole.setDividerSize(10);
        jf.add(hole);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new SplitPaneTest().init();
    }
}

TabbedPane - 标签页面板

用于在同一窗口内切换不同内容区域。

import javax.swing.*;
import java.awt.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;

public class JTabbedPaneTest {
    JFrame jf = new JFrame("测试 JTabbedPane");
    JTabbedPane tabbedPane = new JTabbedPane(SwingConstants.LEFT, JTabbedPane.SCROLL_TAB_LAYOUT);

    public void init() {
        tabbedPane.addTab("用户管理", new ImageIcon("swing\\img\\container\\open.gif"), 
            new JList<String>(new String[]{"用户一", "用户二", "用户三"}));
        tabbedPane.addTab("商品管理", new JList<String>(new String[]{"商品一", "商品二", "商品三"}));
        tabbedPane.addTab("订单管理", new ImageIcon("swing\\img\\container\\open.gif"), 
            new JList<String>(new String[]{"订单一", "订单二", "订单三", "订单四"}));

        tabbedPane.setEnabledAt(0, false); // 禁用第一个标签
        tabbedPane.setSelectedIndex(1); // 默认选中第二个

        tabbedPane.addChangeListener(e -> {
            int selectedIndex = tabbedPane.getSelectedIndex();
            JOptionPane.showMessageDialog(jf, "当前选中了第 " + (selectedIndex + 1) + "个标签");
        });

        jf.add(tabbedPane);
        jf.setBounds(400, 400, 400, 400);
        jf.setResizable(false);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new JTabbedPaneTest().init();
    }
}

三、Swing 布局

1. BorderLayout

边界布局将容器分为北、南、东、西、中五个区域。未设置的区域会自动留空，适合实现行列布局模式。

import javax.swing.*;
import java.awt.*;

public class BorderLayoutTest extends JFrame {
    public BorderLayoutTest() {
        JButton jButton = new JButton("中间");
        JButton jButton2 = new JButton("北间");
        JButton jButton3 = new JButton("西间");
        JButton jButton4 = new JButton("东间");
        JButton jButton5 = new JButton("南间");

        this.add(jButton, BorderLayout.CENTER);
        this.add(jButton2, BorderLayout.NORTH);
        this.add(jButton3, BorderLayout.WEST);
        this.add(jButton4, BorderLayout.EAST);
        this.add(jButton5, BorderLayout.SOUTH);

        this.setTitle("演示边界布局管理器");
        this.setSize(300, 200);
        this.setLocation(200, 200);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public static void main(String[] args) {
        new BorderLayoutTest();
    }
}

2. FlowLayout

流式布局按添加顺序依次摆放，超出容器宽度自动换行。

import javax.swing.*;
import java.awt.*;

public class FlowLayoutTest extends JFrame {
    public FlowLayoutTest() {
        JButton jButton1 = new JButton("A");
        JButton jButton2 = new JButton("B");
        JButton jButton3 = new JButton("C");
        JButton jButton4 = new JButton("D");
        JButton jButton5 = new JButton("E");

        this.add(jButton1);
        this.add(jButton2);
        this.add(jButton3);
        this.add(jButton4);
        this.add(jButton5);

        this.setLayout(new FlowLayout(FlowLayout.LEFT));
        this.setTitle("演示流布局管理器");
        this.setSize(300, 200);
        this.setLocation(200, 200);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setResizable(false);
    }

    public static void main(String[] args) {
        new FlowLayoutTest();
    }
}

3. GridLayout

网格布局适合规则排列，每个单元格大小一致。

import javax.swing.*;
import java.awt.*;

public class GridLayoutTest extends JFrame {
    int size = 9;
    JButton[] jButton = new JButton[size];

    public GridLayoutTest() {
        for (int i = 0; i < size; i++) {
            jButton[i] = new JButton(String.valueOf(i + 1));
            this.add(jButton[i]);
        }
        this.setLayout(new GridLayout(3, 3, 10, 30));
        this.setTitle("演示网格布局管理器");
        this.setSize(400, 400);
        this.setLocation(200, 200);
        this.setVisible(true);
        this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        this.setResizable(false);
    }

    public static void main(String[] args) {
        new GridLayoutTest();
    }
}

4. BoxLayout

可指定元素是按行还是按列排列。

import javax.swing.*;
import java.awt.*;

public class BoxLayoutTest {
    public static void main(String[] args) {
        Frame frame = new Frame("这里测试 BoxLayout");
        // 水平排列
        BoxLayout boxLayout = new BoxLayout(frame, BoxLayout.X_AXIS);
        frame.setLayout(boxLayout);
        frame.add(new Button("按钮 1"));
        frame.add(new Button("按钮 2"));
        frame.pack();
        frame.setVisible(true);
    }
}

四、Swing 事件

事件源可以绑定多个监听器，也允许多个同类型事件源共享一个监听器。内部会形成事件链依次执行。

1. 定制侦听器

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class EventDemo1 {
    Frame frame = new Frame("这里测试事件处理");
    TextField tf = new TextField(30);
    Button ok = new Button("确定");

    public void init() {
        ok.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("ok 按钮被点击了...");
                tf.setText("Hello World");
            }
        });
        frame.add(tf, BorderLayout.NORTH);
        frame.add(ok);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        new EventDemo1().init();
    }
}

2. 共享侦听器

适合公共逻辑复用。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

class MyListener implements ActionListener {
    @Override
    public void actionPerformed(ActionEvent e) {
        System.out.println("ok 按钮被点击了...");
    }
}

public class EventDemoShared {
    Frame frame = new Frame("这里测试事件处理");
    TextField tf = new TextField(30);
    Button ok = new Button("确定");

    public void init() {
        MyListener myListener = new MyListener();
        ok.addActionListener(myListener);
        frame.add(tf, BorderLayout.NORTH);
        frame.add(ok);
        frame.pack();
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        new EventDemoShared().init();
    }
}

五、Swing 进度条

主要使用 JProgressBar、ProgressMonitor、BoundedRangeModel 实现。

1. 主线程内的进度条

注意： 耗时操作放在主线程会导致界面卡死，实际开发中建议放入子线程。

import javax.swing.*;
import java.awt.*;

public class JProgressTest {
    JFrame jf = new JFrame("测试进度条");
    JProgressBar bar = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);

    public void init() {
        Box vBox = Box.createVerticalBox();
        bar.setStringPainted(true);
        bar.setBorderPainted(true);
        jf.setLayout(new FlowLayout());
        jf.add(vBox);
        jf.add(bar);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);

        for (int i = 0; i <= 100; i++) {
            bar.setValue(i);
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                e.printStackTrace();
            }
        }
    }

    public static void main(String[] args) {
        new JProgressTest().init();
    }
}

2. 线程内的进度条（推荐）

通过子线程模拟耗时任务，定时更新 UI。

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

public class JProgressTest2 {
    JFrame jf = new JFrame("测试进度条");
    JProgressBar bar = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);

    public void init() {
        Box vBox = Box.createVerticalBox();
        bar.setStringPainted(true);
        bar.setBorderPainted(true);
        jf.setLayout(new FlowLayout());
        jf.add(vBox);
        jf.add(bar);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);

        SimulaterActivity simulaterActivity = new SimulaterActivity();
        simulaterActivity.setAmount(bar.getMaximum());
        new Thread(simulaterActivity).start();

        Timer timer = new Timer(200, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int current = simulaterActivity.getCurrent();
                bar.setValue(current);
            }
        });
        timer.start();

        bar.addChangeListener(e -> {
            int value = bar.getValue();
            if (value == simulaterActivity.getAmount()) {
                timer.stop();
            }
        });
    }

    @Data
    private class SimulaterActivity implements Runnable {
        private int amount;
        private volatile int current;

        @Override
        public void run() {
            while (current < amount) {
                try {
                    Thread.currentThread().sleep(50);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                current++;
            }
        }
    }

    public static void main(String[] args) {
        new JProgressTest2().init();
    }
}

3. 获取进度条数据

Swing 组件将外观与数据分离，JProgressBar 内置 BoundedRangeModel 保存状态。通过 Model 可以更灵活地控制数据。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class JProgressTest3 {
    JFrame jf = new JFrame("测试进度条");
    JProgressBar bar = new JProgressBar(JProgressBar.HORIZONTAL, 0, 100);
    BoundedRangeModel model = bar.getModel();

    public void init() {
        Box vBox = Box.createVerticalBox();
        bar.setStringPainted(true);
        bar.setBorderPainted(true);
        jf.setLayout(new FlowLayout());
        jf.add(vBox);
        jf.add(bar);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);

        SimulaterActivity simulaterActivity = new SimulaterActivity();
        simulaterActivity.setAmount(bar.getMaximum());
        new Thread(simulaterActivity).start();

        Timer timer = new Timer(200, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int current = simulaterActivity.getCurrent();
                model.setValue(current);
            }
        });
        timer.start();

        model.addChangeListener(e -> {
            int value = model.getValue();
            if (value == simulaterActivity.getAmount()) {
                timer.stop();
            }
        });
    }

    @Data
    private class SimulaterActivity implements Runnable {
        private int amount;
        private volatile int current;

        @Override
        public void run() {
            while (current < amount) {
                try {
                    Thread.currentThread().sleep(50);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                current++;
            }
        }
    }

    public static void main(String[] args) {
        new JProgressTest3().init();
    }
}

4. ProgressMonitor

ProgressMonitor 创建的对话框包含固定样式的进度条，不可自定义边框或方向，但使用简单。

import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class ProgressMonitorTest {
    Timer timer;

    public void init() {
        ProgressMonitor monitor = new ProgressMonitor(null, "等待任务完成", "已完成", 0, 100);
        SimulaterActivity simulaterActivity = new SimulaterActivity(100);
        new Thread(simulaterActivity).start();

        timer = new Timer(200, new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                int current = simulaterActivity.getCurrent();
                monitor.setProgress(current);
                if (monitor.isCanceled()) {
                    timer.stop();
                    monitor.close();
                    System.exit(0);
                }
            }
        });
        timer.start();
    }

    @Data
    private class SimulaterActivity implements Runnable {
        private volatile int current = 0;
        private int amount;

        public SimulaterActivity(int amount) {
            this.amount = amount;
        }

        @Override
        public void run() {
            while (current < amount) {
                try {
                    Thread.sleep(50);
                } catch (InterruptedException e) {
                    e.printStackTrace();
                }
                current++;
            }
        }
    }

    public static void main(String[] args) {
        new ProgressMonitorTest().init();
    }
}

六、Swing 下拉列表

1. 简单列表

展示基本的 JList 和 JComboBox 用法。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.List;

public class ListTest {
    JFrame jf = new JFrame("列表框测试");
    String[] books = {"java 自学宝典", "轻量级 javaEE 企业应用实战", "Android 基础教程", "jQuery 实战教程", "SpringBoot 企业级开发"};
    JPanel layoutPanel = new JPanel();
    ButtonGroup layoutGroup = new ButtonGroup();
    JPanel selectModePanel = new JPanel();
    ButtonGroup selectModeGroup = new ButtonGroup();
    JList<String> bookList;
    JComboBox<String> bookSelector;

    public void init() {
        bookList = new JList<>(books);
        addBtn2LayoutPanel("纵向滚动", JList.VERTICAL);
        addBtn2LayoutPanel("纵向换行", JList.VERTICAL_WRAP);
        addBtn2LayoutPanel("横向换行", JList.HORIZONTAL_WRAP);
        addBtn2SelectModelPanel("无限制", ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
        addBtn2SelectModelPanel("单选", ListSelectionModel.SINGLE_SELECTION);
        addBtn2SelectModelPanel("单范围", ListSelectionModel.SINGLE_INTERVAL_SELECTION);

        bookList.setVisibleRowCount(3);
        bookList.setSelectionInterval(2, 4);

        bookList.addListSelectionListener(e -> {
            List<String> selectedValuesList = bookList.getSelectedValuesList();
            // 此处可处理选中逻辑
        });

        Box bookListVBox = Box.createVerticalBox();
        bookListVBox.add(new JScrollPane(bookList));
        bookListVBox.add(layoutPanel);
        bookListVBox.add(selectModePanel);

        Vector<String> vector = new Vector<>();
        for (String book : books) vector.add(book);
        bookSelector = new JComboBox<>(vector);
        bookSelector.setEditable(true);
        bookSelector.setMaximumRowCount(4);

        Box topBox = Box.createHorizontalBox();
        topBox.add(bookListVBox);
        JPanel bookSelectPanel = new JPanel();
        bookSelectPanel.add(bookSelector);
        topBox.add(bookSelectPanel);

        JPanel bottomPanel = new JPanel();
        bottomPanel.setLayout(new BorderLayout());

        Box holeBox = Box.createVerticalBox();
        holeBox.add(topBox);
        holeBox.add(bottomPanel);
        jf.add(holeBox);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public void addBtn2LayoutPanel(String name, int layoutType) {
        layoutPanel.setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), "确定选项布局"));
        JRadioButton button = new JRadioButton(name);
        layoutPanel.add(button);
        if (layoutGroup.getButtonCount() == 0) button.setSelected(true);
        layoutGroup.add(button);
        button.addActionListener(e -> bookList.setLayoutOrientation(layoutType));
    }

    public void addBtn2SelectModelPanel(String name, int selectionModel) {
        selectModePanel.setBorder(BorderFactory.createTitledBorder(BorderFactory.createEtchedBorder(), "确定选择模式"));
        JRadioButton button = new JRadioButton(name);
        selectModePanel.add(button);
        if (selectModeGroup.getButtonCount() == 0) button.setSelected(true);
        selectModeGroup.add(button);
        button.addActionListener(e -> bookList.setSelectionMode(selectionModel));
    }

    public static void main(String[] args) {
        new ListTest().init();
    }
}

2. 固定值的列表

自定义 ListModel 生成连续数值。

import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import java.math.BigDecimal;
import java.math.RoundingMode;
import java.util.Vector;

public class NumberListModel extends AbstractListModel<BigDecimal> {
    BigDecimal start, end, step;

    public NumberListModel(BigDecimal start, BigDecimal end, BigDecimal step) {
        this.start = start;
        this.end = end;
        this.step = step;
    }

    @Override
    public int getSize() {
        int floor = (int) Math.floor(end.subtract(start).divide(step, 2, RoundingMode.HALF_DOWN).doubleValue());
        return floor + 1;
    }

    @Override
    public BigDecimal getElementAt(int index) {
        BigDecimal ele = new BigDecimal(index).multiply(step).add(start).setScale(2, RoundingMode.HALF_DOWN);
        return ele;
    }
}

public class NumberComboBoxListModel extends NumberListModel implements ComboBoxModel<BigDecimal> {
    private int selectedId;

    public NumberComboBoxListModel(BigDecimal start, BigDecimal end, BigDecimal step) {
        super(start, end, step);
    }

    @Override
    public void setSelectedItem(Object anItem) {
        if (anItem instanceof BigDecimal) {
            BigDecimal curr = (BigDecimal) anItem;
            selectedId = curr.subtract(super.start).divide(super.step, 2, RoundingMode.HALF_DOWN).intValue();
        }
    }

    @Override
    public Object getSelectedItem() {
        BigDecimal item = new BigDecimal(selectedId).multiply(super.step).add(super.start).setScale(1, RoundingMode.HALF_DOWN);
        return item;
    }
}

配合 ListModelTest 使用，展示动态生成的列表项。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ItemEvent;
import java.awt.event.ItemListener;
import java.math.BigDecimal;
import java.util.List;

public class ListModelTest {
    JFrame jf = new JFrame("测试 ListModel");
    JList<BigDecimal> jList = new JList<>(new NumberListModel(new BigDecimal(1), new BigDecimal(21), new BigDecimal(2)));
    JComboBox<BigDecimal> jComboBox = new JComboBox<>(new NumberComboBoxListModel(new BigDecimal(0.1), new BigDecimal(1.2), new BigDecimal(0.1)));
    JLabel label = new JLabel("您选择的值是：");
    JTextField jTextField = new JTextField(15);

    public void init() {
        jList.setVisibleRowCount(4);
        jList.setSelectionInterval(2, 4);
        jList.setFixedCellWidth(90);
        jList.setFixedCellHeight(30);
        jList.addListSelectionListener(e -> {
            List<BigDecimal> selectedValuesList = jList.getSelectedValuesList();
            jTextField.setText("");
            for (BigDecimal item : selectedValuesList) {
                jTextField.setText(jTextField.getText() + item.toString() + ",");
            }
        });
        jComboBox.setMaximumRowCount(4);
        jComboBox.addItemListener(e -> {
            Object selectedItem = jComboBox.getSelectedItem();
            jTextField.setText(selectedItem.toString());
        });

        Box hBox = Box.createHorizontalBox();
        hBox.add(new JScrollPane(jList));
        JPanel tempPanel = new JPanel();
        tempPanel.add(jComboBox);
        hBox.add(tempPanel);
        jf.add(hBox);

        JPanel bottomPanel = new JPanel();
        bottomPanel.add(label);
        bottomPanel.add(jTextField);
        jf.add(bottomPanel, BorderLayout.SOUTH);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new ListModelTest().init();
    }
}

3. 动态改变列表的值

使用 DefaultListModel 实现列表数据的增删改。

import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class DefaultListModelTest {
    JFrame jf = new JFrame("测试 DefaultListModel");
    JTextField bookName = new JTextField(20);
    JButton removeBtn = new JButton("删除选中图书");
    JButton addBtn = new JButton("添加指定图书");
    JList<String> bookList;
    DefaultListModel<String> model = new DefaultListModel<>();

    public void init() {
        model.addElement("java 自学宝典");
        model.addElement("轻量级 JavaEE 企业应用实战");
        model.addElement("Android 基础教程");
        model.addElement("JQuery 实战教程");
        bookList = new JList<>(model);
        bookList.setVisibleRowCount(4);
        bookList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
        jf.add(new JScrollPane(bookList));

        addBtn.addActionListener(e -> {
            String name = bookName.getText();
            if (!name.trim().equals("")) {
                model.addElement(name);
            }
        });
        removeBtn.addActionListener(e -> {
            int selectedIndex = bookList.getSelectedIndex();
            if (selectedIndex >= 0) {
                model.remove(selectedIndex);
            }
        });

        JPanel bottomPanel = new JPanel();
        bottomPanel.add(bookName);
        bottomPanel.add(addBtn);
        bottomPanel.add(removeBtn);
        jf.add(bottomPanel, BorderLayout.SOUTH);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new DefaultListModelTest().init();
    }
}

4. 改变列表控件外观

通过 ListCellRenderer 自定义列表项的绘制方式。

import javax.swing.*;
import java.awt.*;

public class ListCellRendererTest {
    private JFrame mainWin = new JFrame("好友列表");
    private String[] friends = {"李清照", "苏格拉底", "李白", "弄玉", "虎头"};
    private JList friendsList = new JList(friends);

    public void init() {
        friendsList.setCellRenderer(new MyRenderer());
        mainWin.add(friendsList);
        mainWin.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        mainWin.pack();
        mainWin.setVisible(true);
    }

    private class MyRenderer extends JPanel implements ListCellRenderer {
        private String name;
        private ImageIcon icon;
        private Color backGround;
        private Color forceGround;

        @Override
        public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
            this.name = value.toString();
            this.icon = new ImageIcon("E:\\GUISwing\\img\\tree\\" + name + ".gif");
            this.backGround = isSelected ? list.getSelectionBackground() : list.getBackground();
            this.forceGround = isSelected ? list.getSelectionForeground() : list.getForeground();
            return this;
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(60, 80);
        }

        @Override
        public void paint(Graphics g) {
            int imageWidth = icon.getImage().getWidth(null);
            int imageHeight = icon.getImage().getHeight(null);
            g.setColor(backGround);
            g.fillRect(0, 0, getWidth(), getHeight());
            g.drawImage(icon.getImage(), getWidth() / 2 - imageWidth / 2, 10, null);
            g.setColor(forceGround);
            g.setFont(new Font("StSong", Font.BOLD, 18));
            g.drawString(this.name, getWidth() / 2 - this.name.length() * 20 / 2, imageHeight + 30);
        }
    }

    public static void main(String[] args) {
        new ListCellRendererTest().init();
    }
}

七、Swing 表格

1. 简单表格

直接传入二维数组初始化表格。

import javax.swing.*;
import java.awt.*;

public class SimpleTable {
    JFrame jf = new JFrame("简单表格");
    Object[] titles = {"姓名", "年龄", "性别"};
    Object[][] data = {
        {"李清照", 29, "女"},
        {"苏格拉底", 56, "男"},
        {"李白", 35, "男"},
        {"弄玉", 18, "女"},
        {"虎头", 2, "男"}
    };

    public void init() {
        JTable jTable = new JTable(data, titles);
        jf.add(new JScrollPane(jTable));
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new SimpleTable().init();
    }
}

2. TableModel

自定义 TableModel 实现更灵活的数据交互。

import javax.swing.*;
import javax.swing.table.AbstractTableModel;
import javax.swing.table.DefaultTableModel;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Vector;

public class TableModelTest {
    JFrame jf = new JFrame("TableModel 演示");
    Object[] titles = {"姓名", "年龄", "性别"};
    Object[][] data = {
        {"李清照", 29, "女"},
        {"苏格拉底", 56, "男"},
        {"李白", 35, "男"},
        {"弄玉", 18, "女"},
        {"虎头", 2, "男"}
    };
    private Vector titlesV = new Vector();
    private Vector<Vector> dataV = new Vector<>();

    public void init() {
        for (int i = 0; i < titles.length; i++) titlesV.add(titles[i]);
        for (int i = 0; i < data.length; i++) {
            Vector t = new Vector<>();
            for (int j = 0; j < data[i].length; j++) t.add(data[i][j]);
            dataV.add(t);
        }
        MyTableModel myTableModel = new MyTableModel();
        JTable jTable = new JTable(myTableModel);
        jf.add(new JScrollPane(jTable));

        JButton btn = new JButton("获取选中行数据");
        btn.addActionListener(e -> {
            int selectedColumn = jTable.getSelectedColumn();
            int selectedRow = jTable.getSelectedRow();
            System.out.println("当前选中行的索引：" + selectedRow);
            System.out.println("当前选中列的索引：" + selectedColumn);
            Object value = myTableModel.getValueAt(selectedRow, selectedColumn);
            System.out.println("当前选中行第一个单元格的内容为：" + value);
        });
        jf.add(btn, BorderLayout.SOUTH);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    private class MyTableModel extends AbstractTableModel {
        @Override
        public int getRowCount() { return dataV.size(); }
        @Override
        public int getColumnCount() { return titlesV.size(); }
        @Override
        public Object getValueAt(int rowIndex, int columnIndex) { return dataV.get(rowIndex).get(columnIndex); }
        @Override
        public String getColumnName(int column) { return (String) titlesV.get(column); }
        @Override
        public boolean isCellEditable(int rowIndex, int columnIndex) { return false; }
    }

    public static void main(String[] args) {
        new TableModelTest().init();
    }
}

public class DefaultTableModelTest {
    JFrame jf = new JFrame("TableModel 演示");
    Object[] titles = {"姓名", "年龄", "性别"};
    Object[][] data = {
        {"李清照", 29, "女"},
        {"苏格拉底", 56, "男"},
        {"李白", 35, "男"},
        {"弄玉", 18, "女"},
        {"虎头", 2, "男"}
    };
    private Vector titlesV = new Vector();
    private Vector<Vector> dataV = new Vector<>();

    public void init() {
        for (int i = 0; i < titles.length; i++) titlesV.add(titles[i]);
        for (int i = 0; i < data.length; i++) {
            Vector t = new Vector<>();
            for (int j = 0; j < data[i].length; j++) t.add(data[i][j]);
            dataV.add(t);
        }
        DefaultTableModel model = new DefaultTableModel(dataV, titlesV);
        JTable jTable = new JTable(model);

        JButton addRow = new JButton("添加一行");
        JButton addColum = new JButton("添加一列");
        JButton deleteRow = new JButton("删除一行");

        addRow.addActionListener(e -> model.addRow(new Object[]{"胡歌", 30, "男"}));
        deleteRow.addActionListener(e -> {
            int selectedRow = jTable.getSelectedRow();
            model.removeRow(selectedRow);
        });
        addColum.addActionListener(e -> model.addColumn("职业"));

        JPanel panel = new JPanel();
        panel.add(addRow);
        panel.add(addColum);
        panel.add(deleteRow);
        jf.add(panel, BorderLayout.SOUTH);
        jf.add(new JScrollPane(jTable));
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new DefaultTableModelTest().init();
    }
}

八、Swing 树

1. 创建树

使用 DefaultMutableTreeNode 构建树形结构。

import javax.swing.*;
import java.awt.*;

public class SimpleJTree {
    JFrame jf = new JFrame("简单树");

    public void init() {
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("中国");
        DefaultMutableTreeNode guangDong = new DefaultMutableTreeNode("广东");
        DefaultMutableTreeNode guangXi = new DefaultMutableTreeNode("广西");
        DefaultMutableTreeNode foShan = new DefaultMutableTreeNode("佛山");
        DefaultMutableTreeNode shanTou = new DefaultMutableTreeNode("汕头");
        DefaultMutableTreeNode guiLin = new DefaultMutableTreeNode("桂林");
        DefaultMutableTreeNode nanNing = new DefaultMutableTreeNode("南宁");

        root.add(guangDong);
        root.add(guangXi);
        guangDong.add(foShan);
        guangDong.add(shanTou);
        guangXi.add(guiLin);
        guangXi.add(nanNing);

        JTree tree = new JTree(root);
        jf.add(tree);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new SimpleJTree().init();
    }
}

2. 编辑树

编辑树节点

支持添加、删除、修改节点。

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

public class EditTree {
    JFrame jf = new JFrame("可编辑结点的树");
    DefaultMutableTreeNode root = new DefaultMutableTreeNode("中国");
    DefaultMutableTreeNode guangdong = new DefaultMutableTreeNode("广东");
    DefaultMutableTreeNode guangxi = new DefaultMutableTreeNode("广西");
    DefaultMutableTreeNode foshan = new DefaultMutableTreeNode("佛山");
    DefaultMutableTreeNode shantou = new DefaultMutableTreeNode("汕头");
    DefaultMutableTreeNode guilin = new DefaultMutableTreeNode("桂林");
    DefaultMutableTreeNode nanning = new DefaultMutableTreeNode("南宁");
    JButton addSiblingBtn = new JButton("添加兄弟结点");
    JButton addChildBtn = new JButton("添加子结点");
    JButton deleteBtn = new JButton("删除结点");
    JButton editBtn = new JButton("编辑当前结点");

    public void init() {
        guangdong.add(foshan);
        guangdong.add(shantou);
        guangxi.add(guilin);
        guangxi.add(nanning);
        root.add(guangdong);
        root.add(guangxi);

        JTree tree = new JTree(root);
        tree.setEditable(true);
        DefaultTreeModel model = (DefaultTreeModel) tree.getModel();

        addSiblingBtn.addActionListener(e -> {
            DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
            if (selectedNode == null) return;
            DefaultMutableTreeNode parentNode = (DefaultMutableTreeNode) selectedNode.getParent();
            if (parentNode == null) return;
            DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("新结点");
            int index = parentNode.getIndex(selectedNode);
            model.insertNodeInto(newNode, parentNode, index);
            TreeNode[] pathToRoot = model.getPathToRoot(newNode);
            TreePath treePath = new TreePath(pathToRoot);
            tree.scrollPathToVisible(treePath);
            tree.updateUI();
        });

        addChildBtn.addActionListener(e -> {
            DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
            if (selectedNode == null) return;
            DefaultMutableTreeNode newNode = new DefaultMutableTreeNode("新结点");
            selectedNode.add(newNode);
            TreeNode[] pathToRoot = model.getPathToRoot(newNode);
            TreePath treePath = new TreePath(pathToRoot);
            tree.scrollPathToVisible(treePath);
            tree.updateUI();
        });

        deleteBtn.addActionListener(e -> {
            DefaultMutableTreeNode selectedNode = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();
            if (selectedNode != null && selectedNode.getParent() != null) {
                model.removeNodeFromParent(selectedNode);
            }
        });

        editBtn.addActionListener(e -> {
            TreePath selectionPath = tree.getSelectionPath();
            if (selectionPath != null) {
                tree.startEditingAtPath(selectionPath);
            }
        });

        jf.add(new JScrollPane(tree));
        JPanel panel = new JPanel();
        panel.add(addSiblingBtn);
        panel.add(addChildBtn);
        panel.add(deleteBtn);
        panel.add(editBtn);
        jf.add(panel, BorderLayout.SOUTH);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.pack();
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new EditTree().init();
    }
}

监听节点事件

监听树的选择变化。

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;
import java.awt.*;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;

public class ListenerJTree {
    JFrame jf = new JFrame("监听树的选择事件");
    JTree tree;
    DefaultMutableTreeNode root = new DefaultMutableTreeNode("中国");
    DefaultMutableTreeNode guangdong = new DefaultMutableTreeNode("广东");
    DefaultMutableTreeNode guangxi = new DefaultMutableTreeNode("广西");
    DefaultMutableTreeNode foshan = new DefaultMutableTreeNode("佛山");
    DefaultMutableTreeNode shantou = new DefaultMutableTreeNode("汕头");
    DefaultMutableTreeNode guilin = new DefaultMutableTreeNode("桂林");
    DefaultMutableTreeNode nanning = new DefaultMutableTreeNode("南宁");
    JTextArea eventTxt = new JTextArea(5, 20);

    public void init() {
        guangdong.add(foshan);
        guangdong.add(shantou);
        guangxi.add(guilin);
        guangxi.add(nanning);
        root.add(guangdong);
        root.add(guangxi);
        tree = new JTree(root);

        TreeSelectionModel selectionModel = tree.getSelectionModel();
        selectionModel.setSelectionMode(TreeSelectionModel.SINGLE_TREE_SELECTION);

        tree.addTreeSelectionListener(e -> {
            TreePath newLeadSelectionPath = e.getNewLeadSelectionPath();
            eventTxt.append(newLeadSelectionPath.toString() + "\n");
        });

        Box box = Box.createHorizontalBox();
        box.add(new JScrollPane(tree));
        box.add(new JScrollPane(eventTxt));
        jf.add(box);
        jf.pack();
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new ListenerJTree().init();
    }
}

3. 改变树外观

通过 TreeCellRenderer 自定义节点图标和颜色。

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellRenderer;
import java.awt.*;

public class ChangeAllCellRender {
    JFrame jf = new JFrame("改变所有结点外观");
    JTree tree;
    DefaultMutableTreeNode root = new DefaultMutableTreeNode("中国");
    DefaultMutableTreeNode guangdong = new DefaultMutableTreeNode("广东");
    DefaultMutableTreeNode guangxi = new DefaultMutableTreeNode("广西");
    DefaultMutableTreeNode foshan = new DefaultMutableTreeNode("佛山");
    DefaultMutableTreeNode shantou = new DefaultMutableTreeNode("汕头");
    DefaultMutableTreeNode guilin = new DefaultMutableTreeNode("桂林");
    DefaultMutableTreeNode nanning = new DefaultMutableTreeNode("南宁");

    public void init() {
        guangdong.add(foshan);
        guangdong.add(shantou);
        guangxi.add(guilin);
        guangxi.add(nanning);
        root.add(guangdong);
        root.add(guangxi);
        tree = new JTree(root);

        DefaultTreeCellRenderer renderer = new DefaultTreeCellRenderer();
        renderer.setBackgroundNonSelectionColor(new Color(220, 220, 220));
        renderer.setBackgroundSelectionColor(new Color(140, 140, 140));
        renderer.setBorderSelectionColor(Color.BLACK);
        renderer.setClosedIcon(new ImageIcon("E:\\GUISwing\\img\\tree\\close.gif"));
        renderer.setFont(new Font("StSong", Font.BOLD, 16));
        renderer.setLeafIcon(new ImageIcon("E:\\GUISwing\\img\\tree\\leaf.png"));
        renderer.setOpenIcon(new ImageIcon("E:\\GUISwing\\img\\tree\\open.gif"));
        renderer.setTextNonSelectionColor(new Color(255, 0, 0));
        renderer.setTextSelectionColor(new Color(0, 0, 255));

        tree.setCellRenderer(renderer);
        jf.add(new JScrollPane(tree));
        jf.pack();
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setVisible(true);
    }

    public static void main(String[] args) {
        new ChangeAllCellRender().init();
    }
}

扩展 DefaultTreeCellRenderer 可实现更复杂的图标映射。

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeCellRenderer;
import javax.swing.tree.TreeCellRenderer;
import java.awt.*;

public class ExtendsDefaultCellTreeRenderer {
    JFrame jf = new JFrame("根据结点类型定义图标");
    JTree tree;
    ImageIcon rootIcon = new ImageIcon("E:\\GUISwing\\img\\tree\\root.gif");
    ImageIcon databaseIcon = new ImageIcon("E:\\GUISwing\\img\\tree\\database.gif");
    ImageIcon tableIcon = new ImageIcon("E:\\GUISwing\\img\\tree\\table.gif");
    ImageIcon columnIcon = new ImageIcon("E:\\GUISwing\\img\\tree\\column.gif");
    ImageIcon indexIcon = new ImageIcon("E:\\GUISwing\\img\\tree\\index.gif");

    class NodeData {
        public ImageIcon icon;
        public String name;
        public NodeData(ImageIcon icon, String name) {
            this.icon = icon;
            this.name = name;
        }
    }

    DefaultMutableTreeNode root = new DefaultMutableTreeNode(new NodeData(rootIcon, "数据库导航"));
    DefaultMutableTreeNode salaryDb = new DefaultMutableTreeNode(new NodeData(databaseIcon, "公司工资数据库"));
    DefaultMutableTreeNode customerDb = new DefaultMutableTreeNode(new NodeData(databaseIcon, "公司客户数据库"));
    DefaultMutableTreeNode employee = new DefaultMutableTreeNode(new NodeData(tableIcon, "员工表"));
    DefaultMutableTreeNode attend = new DefaultMutableTreeNode(new NodeData(tableIcon, "考勤表"));
    DefaultMutableTreeNode concat = new DefaultMutableTreeNode(new NodeData(tableIcon, "联系方式表"));
    DefaultMutableTreeNode id = new DefaultMutableTreeNode(new NodeData(indexIcon, "员工 ID"));
    DefaultMutableTreeNode name = new DefaultMutableTreeNode(new NodeData(columnIcon, "姓名"));
    DefaultMutableTreeNode gender = new DefaultMutableTreeNode(new NodeData(columnIcon, "性别"));

    public void init() {
        root.add(salaryDb);
        root.add(customerDb);
        salaryDb.add(employee);
        salaryDb.add(attend);
        customerDb.add(concat);
        concat.add(id);
        concat.add(name);
        concat.add(gender);
        tree = new JTree(root);
        tree.setCellRenderer(new MyRenderer());
        jf.add(new JScrollPane(tree));
        jf.pack();
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setVisible(true);
    }

    private class MyRenderer extends DefaultTreeCellRenderer {
        @Override
        public Component getTreeCellRendererComponent(JTree tree, Object value, boolean sel, boolean expanded, boolean leaf, int row, boolean hasFocus) {
            DefaultMutableTreeNode node = (DefaultMutableTreeNode) value;
            NodeData nodeData = (NodeData) node.getUserObject();
            this.setText(nodeData.name);
            this.setIcon(nodeData.icon);
            return this;
        }
    }

    public static void main(String[] args) {
        new ExtendsDefaultCellTreeRenderer().init();
    }
}

完全自定义 TreeCellRenderer 接口可实现像素级控制。

import javax.swing.*;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreeCellRenderer;
import java.awt.*;

public class CustomerTreeNode {
    JFrame jf = new JFrame("定制树的结点");
    JTree tree;
    DefaultMutableTreeNode friends = new DefaultMutableTreeNode("我的好友");
    DefaultMutableTreeNode qingzhao = new DefaultMutableTreeNode("李清照");
    DefaultMutableTreeNode suge = new DefaultMutableTreeNode("苏格拉底");
    DefaultMutableTreeNode libai = new DefaultMutableTreeNode("李白");
    DefaultMutableTreeNode nongyu = new DefaultMutableTreeNode("弄玉");
    DefaultMutableTreeNode hutou = new DefaultMutableTreeNode("虎头");

    public void init() {
        friends.add(qingzhao);
        friends.add(suge);
        friends.add(libai);
        friends.add(nongyu);
        friends.add(hutou);
        tree = new JTree(friends);
        MyRenderer renderer = new MyRenderer();
        tree.setCellRenderer(renderer);
        jf.add(new JScrollPane(tree));
        jf.pack();
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        jf.setVisible(true);
    }

    private class MyRenderer extends JPanel implements TreeCellRenderer {
        private ImageIcon icon;
        private String name;
        private Color background;
        private Color foreground;

        @Override
        public Component getTreeCellRendererComponent(JTree tree, Object value, boolean selected, boolean expanded, boolean leaf, int row, boolean hasFocus) {
            this.icon = new ImageIcon("E:\\GUISwing\\img\\tree\\" + value.toString() + ".gif");
            this.name = value.toString();
            this.background = hasFocus ? new Color(144, 200, 225) : new Color(255, 255, 255);
            this.foreground = hasFocus ? new Color(255, 255, 3) : new Color(0, 0, 0);
            return this;
        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(80, 80);
        }

        @Override
        public void paint(Graphics g) {
            int iconWidth = this.icon.getIconWidth();
            int iconHeight = this.icon.getIconHeight();
            g.setColor(background);
            g.fillRect(0, 0, getWidth(), getHeight());
            g.drawImage(this.icon.getImage(), getWidth() / 2 - iconWidth / 2, 10, null);
            g.setColor(foreground);
            g.setFont(new Font("StSong", Font.BOLD, 18));
            g.drawString(this.name, getWidth() / 2 - this.name.length() * 20 / 2, iconHeight + 30);
        }
    }

    public static void main(String[] args) {
        new CustomerTreeNode().init();
    }
}

九、Swing 控件修饰

1. 控件边框

使用 BorderFactory 可以快速为组件添加各种边框效果。

import javax.swing.*;
import java.awt.*;

public class BorderTest {
    JFrame jf = new JFrame("测试边框");

    public void init() {
        jf.setLayout(new GridLayout(2, 4));
        jf.add(getJPanelWithBorder(BorderFactory.createBevelBorder(BevelBorder.RAISED, Color.RED, Color.GREEN, Color.BLUE, Color.GRAY), "BevelBorder"));
        jf.add(getJPanelWithBorder(BorderFactory.createLineBorder(Color.ORANGE, 10), "LineBorder"));
        jf.add(getJPanelWithBorder(BorderFactory.createEmptyBorder(10, 5, 20, 10), "EmptyBorder"));
        jf.add(getJPanelWithBorder(BorderFactory.createEtchedBorder(EtchedBorder.RAISED, Color.RED, Color.GREEN), "EtchedBorder"));
        jf.add(getJPanelWithBorder(new TitledBorder(new LineBorder(Color.ORANGE, 10), "测试标题", TitledBorder.LEFT, TitledBorder.BOTTOM, new Font("StSong", Font.BOLD, 18), Color.BLUE), "TitledBorder"));
        jf.add(getJPanelWithBorder(new MatteBorder(10, 5, 20, 10, Color.GREEN), "MatteBorder"));
        jf.add(getJPanelWithBorder(new CompoundBorder(new LineBorder(Color.RED, 10), new TitledBorder(new LineBorder(Color.ORANGE, 10), "测试标题")), "CompoundBorder"));
        jf.pack();
        jf.setVisible(true);
        jf.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }

    public JPanel getJPanelWithBorder(Border border, String content) {
        JPanel jPanel = new JPanel();
        jPanel.add(new JLabel(content));
        jPanel.setBorder(border);
        return jPanel;
    }

    public static void main(String[] args) {
        new BorderTest().init();
    }
}