2024-04-20 12:17:35 | 我爱编程网
如果你想在 Java 中调用图形化代码(如 GUI 界面)而不显示图形界面,可以考虑使用无头模式(Headless Mode)来运行你的代码。无头模式允许你在没有显示图形界面的情况下执行图形化代码。
以下是在 Java 中使用无头模式的示例代码:
java
import java.awt.GraphicsEnvironment;
public class HeadlessModeExample {
public static void main(String[] args) {
// 检查是否支持无头模式
if (GraphicsEnvironment.isHeadless()) {
System.out.println("当前环境支持无头模式");
// 在这里编写调用图形化代码的逻辑
// ...
} else {
System.out.println("当前环境不支持无头模式");
}
}
}
在上述代码中,我们使用 GraphicsEnvironment 类的 isHeadless() 方法来检查是否支持无头模式。如果返回 true,则表示当前环境支持无头模式,你可以在该条件下编写调用图形化代码的逻辑;如果返回 false,则表示当前环境不支持无头模式。
import java.awt.*;
import java.awt.event.*;
import java.util.*;
import javax.swing.*;
import javax.swing.border.Border;
class MainFrame extends JFrame {
private static final long serialVersionUID = 1L;
private Map
private Map
private Map
public MainFrame() {
sizes.put("Extra Large", 10);
sizes.put("Large", 8);
sizes.put("Medium", 5);
sizes.put("Small", 3);
styles.put("Deep Dish", 20);
styles.put("Regular", 10);
styles.put("Thin Crust", 5);
styles.put("Chicago", 3);
toppings.put("Cheese", 8);
toppings.put("Tomato", 7);
toppings.put("Peppers", 6);
toppings.put("Peperoni", 5);
this.setTitle("布局及事件处理");
this.setSize(450, 350);
this.setLayout(new BorderLayout());
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JLabel lblTitle = new JLabel();
lblTitle.setText("Pizzeria Juno");
lblTitle.setFont(new Font("宋体", Font.BOLD, 36));
lblTitle.setHorizontalAlignment(SwingConstants.CENTER);
this.add("North", lblTitle);
JPanel bodyPanel = new JPanel();
bodyPanel.setLayout(new GridLayout(2, 1));
this.add("Center", bodyPanel);
JPanel listPanel = new JPanel();
listPanel.setLayout(new GridLayout(1, 3));
listPanel.setSize(200, 200);
bodyPanel.add(listPanel);
Border lineBorder = BorderFactory.createLineBorder(Color.BLACK);
JPanel sizePanel = new JPanel();
sizePanel.setLayout(new BorderLayout());
listPanel.add(sizePanel);
JLabel sizeTitle = new JLabel();
sizeTitle.setText("Sizes");
sizePanel.add("North", sizeTitle);
JList sizeList = new JList(sizes.keySet().toArray());
sizeList.setSize(100, 100);
sizeList.setBorder(lineBorder);
sizeList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
sizePanel.add(sizeList);
JPanel stylePanel = new JPanel();
stylePanel.setLayout(new BorderLayout());
listPanel.add(stylePanel);
JLabel styleTitle = new JLabel();
styleTitle.setText("Styles");
stylePanel.add("North", styleTitle);
JList styleList = new JList(styles.keySet().toArray());
styleList.setSize(100, 100);
styleList.setBorder(lineBorder);
styleList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
stylePanel.add(styleList);
JPanel toppingPanel = new JPanel();
toppingPanel.setLayout(new BorderLayout());
listPanel.add(toppingPanel);
JLabel toppingTitle = new JLabel();
toppingTitle.setText("Toppings");
toppingPanel.add("North", toppingTitle);
JList toppingList = new JList(toppings.keySet().toArray());
toppingList.setSize(100, 100);
toppingList.setBorder(lineBorder);
toppingPanel.add(toppingList);
JTextArea txtResult = new JTextArea();
txtResult.setEditable(false);
bodyPanel.add(txtResult);
JPanel bottomPanel = new JPanel();
bottomPanel.setLayout(new GridLayout(1, 3));
this.add("South", bottomPanel);
JLabel label1 = new JLabel("Click to complete order");
bottomPanel.add(label1);
JButton btnRingUp = new JButton("Ring up");
btnRingUp.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
if(sizeList.getSelectedValue() == null) {
JOptionPane.showMessageDialog(MainFrame.this, "Please select size.");
return;
}
if(styleList.getSelectedValue() == null) {
JOptionPane.showMessageDialog(MainFrame.this, "Please select style.");
return;
}
if(toppingList.getSelectedValue() == null) {
JOptionPane.showMessageDialog(MainFrame.this, "Please select topping.");
return;
}
float total = 0;
String size = sizeList.getSelectedValue().toString();
total += sizes.get(size);
String style = styleList.getSelectedValue().toString();
total += styles.get(style);
String result = size + " Pizza, " + style + " Style";
Object[] toppings = toppingList.getSelectedValues();
for(Object topping : toppings) {
result += "\n +" + topping.toString();
total += MainFrame.this.toppings.get(topping.toString());
}
result += "\n Total: " + total;
txtResult.setText(result);
}
});
bottomPanel.add(btnRingUp);
JButton btnQuit = new JButton("Quit");
btnQuit.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent e) {
MainFrame.this.dispose();
}
});
bottomPanel.add(btnQuit);
}
}
public class App {
public static void main(String[] args) {
MainFrame mainFrame = new MainFrame();
mainFrame.setVisible(true);
}
}
package net.miqiang.gui;
import java.awt.BasicStroke;
import java.awt.BorderLayout;
import java.awt.Button;
import java.awt.Color;
import java.awt.Cursor;
import java.awt.Dimension;
import java.awt.Frame;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridLayout;
import java.awt.Label;
import java.awt.Panel;
import java.awt.RenderingHints;
import java.awt.Toolkit;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.awt.image.BufferedImage;
/**
* 简单画图板程序
* 好久没用 AWT 了,写起来真别扭,如果用 swing 会很舒服,有空再改写吧。
*
* @author 米强
*
*/
public class TestMain extends Frame {
// 画板
private Palette palette = null;
// 显示当前颜色的面板
private Panel nonceColor = null;
// 画笔粗细
private Label drawWidth = null;
// 画笔端点的装饰
private Label drawCap = null;
// 选取颜色按钮的监听事件类
private ButtonColorAction buttonColorAction = null;
// 鼠标进入按钮后光标样式的监听事件类
private ButtonCursor buttonCursor = null;
// 画笔样式的监听事件
private ButtonStrokeAction buttonStrokeAction = null;
/**
* 构造方法
*
*/
public TestMain() {
// 设置标题栏文字
super("简易画图板");
// 构造一个画图板
palette = new Palette();
Panel pane = new Panel(new GridLayout(2, 1));
// 画笔颜色选择器
Panel paneColor = new Panel(new GridLayout(1, 13));
// 12 个颜色选择按钮
Button [] buttonColor = new Button[12];
Color [] color = {Color.black, Color.blue, Color.cyan, Color.darkGray, Color.gray, Color.green, Color.magenta, Color.orange, Color.pink, Color.red, Color.white, Color.yellow};
// 显示当前颜色的面板
nonceColor = new Panel();
nonceColor.setBackground(Color.black);
paneColor.add(nonceColor);
buttonColorAction = new ButtonColorAction();
buttonCursor = new ButtonCursor();
for(int i = 0; i < buttonColor.length; i++){
buttonColor[i] = new Button();
buttonColor[i].setBackground(color[i]);
buttonColor[i].addActionListener(buttonColorAction);
buttonColor[i].addMouseListener(buttonCursor);
paneColor.add(buttonColor[i]);
}
pane.add(paneColor);
// 画笔颜色选择器
Panel paneStroke = new Panel(new GridLayout(1, 13));
// 控制画笔样式
buttonStrokeAction = new ButtonStrokeAction();
Button [] buttonStroke = new Button[11];
buttonStroke[0] = new Button("1");
buttonStroke[1] = new Button("3");
buttonStroke[2] = new Button("5");
buttonStroke[3] = new Button("7");
buttonStroke[4] = new Button("9");
buttonStroke[5] = new Button("11");
buttonStroke[6] = new Button("13");
buttonStroke[7] = new Button("15");
buttonStroke[8] = new Button("17");
buttonStroke[9] = new Button("■");
buttonStroke[10] = new Button("●");
drawWidth = new Label("3", Label.CENTER);
drawCap = new Label("●", Label.CENTER);
drawWidth.setBackground(Color.lightGray);
drawCap.setBackground(Color.lightGray);
paneStroke.add(drawWidth);
for(int i = 0; i < buttonStroke.length; i++){
paneStroke.add(buttonStroke[i]);我爱编程网
buttonStroke[i].addMouseListener(buttonCursor);
buttonStroke[i].addActionListener(buttonStrokeAction);
if(i <= 8){
buttonStroke[i].setName("width");
}else{
buttonStroke[i].setName("cap");
}
if(i == 8){
paneStroke.add(drawCap);
}
}
pane.add(paneStroke);
// 将画笔颜色选择器添加到窗体中
this.add(pane, BorderLayout.NORTH);
// 将画图板添加到窗体中
this.add(palette);
// 添加窗口监听,点击关闭按钮时退出程序
this.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
// 设置窗体 ICON 图标
this.setIconImage(Toolkit.getDefaultToolkit().createImage("images/palette.png"));
// 设置窗口的大小
this.setSize(new Dimension(400, 430));
// 设置窗口位置,处于屏幕正中央
this.setLocationRelativeTo(null);
// 显示窗口
this.setVisible(true);
}
/**
* 程序入口
*
* @param args
* 字符串数组参数
*/
public static void main(String[] args) {
new TestMain();
}
/**
* 选取颜色按钮的监听事件类
* @author 米强
*
*/
class ButtonColorAction implements ActionListener {
public void actionPerformed(ActionEvent e) {
Color color_temp = ((Button)e.getSource()).getBackground();
nonceColor.setBackground(color_temp);
palette.setColor(color_temp);
}
}
/**
* 鼠标进入按钮变换光标样式监听事件类
* @author 米强
*
*/
class ButtonCursor extends MouseAdapter {
public void mouseEntered(MouseEvent e) {
((Button)e.getSource()).setCursor(new Cursor(Cursor.HAND_CURSOR));
}
public void mouseExited(MouseEvent e) {
((Button)e.getSource()).setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
}
}
/**
* 设置画笔的监听事件类
* @author 米强
*
*/
class ButtonStrokeAction implements ActionListener {
public void actionPerformed(ActionEvent e) {
Button button_temp = (Button) e.getSource();
String name = button_temp.getName();
if(name.equalsIgnoreCase("width")){
drawWidth.setText(button_temp.getLabel());
palette.setStroke(Float.parseFloat(button_temp.getLabel()));
}else if(name.equalsIgnoreCase("cap")){
drawCap.setText(button_temp.getLabel());
if(button_temp.getLabel().equals("■")){
palette.setStroke(BasicStroke.CAP_SQUARE);
}else if(button_temp.getLabel().equals("●")){
palette.setStroke(BasicStroke.CAP_ROUND);
}
}
}
}
}
/**
* 画板类
*
* @author 米强
*
*/
class Palette extends Panel implements MouseListener, MouseMotionListener {
// 鼠标 X 坐标的位置
private int mouseX = 0;
// 上一次 X 坐标位置
private int oldMouseX = 0;
// 鼠标 Y 坐标的位置
private int mouseY = 0;
// 上一次 Y 坐标位置
private int oldMouseY = 0;
// 画图颜色
private Color color = null;
// 画笔样式
private BasicStroke stroke = null;
// 缓存图形
private BufferedImage image = null;
/**
* 构造一个画板类
*
*/
public Palette() {
this.addMouseListener(this);
this.addMouseMotionListener(this);
// 默认黑色画笔
color = new Color(0, 0, 0);
// 设置默认画笔样式
stroke = new BasicStroke(3.0f, BasicStroke.CAP_ROUND, BasicStroke.JOIN_ROUND);
// 建立 1280 * 1024 的 RGB 缓存图象
image = new BufferedImage(1280, 1024, BufferedImage.TYPE_INT_RGB);
// 设置颜色
image.getGraphics().setColor(Color.white);
// 画背景
image.getGraphics().fillRect(0, 0, 1280, 1024);
}
/**
* 重写 paint 绘图方法
*/
public void paint(Graphics g) {
super.paint(g);
// 转换为 Graphics2D
Graphics2D g2d = (Graphics2D) g;
// 获取缓存图形 Graphics2D
Graphics2D bg = image.createGraphics();
// 图形抗锯齿
bg.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
// 设置绘图颜色
bg.setColor(color);
// 设置画笔样式
bg.setStroke(stroke);
// 画线,从上一个点到新的点
bg.drawLine(oldMouseX, oldMouseY, mouseX, mouseY);
// 将缓存中的图形画到画板上
g2d.drawImage(image, 0, 0, this);
}
/**
* 重写 update 方法
*/
public void update(Graphics g) {
this.paint(g);
}
/**
* @return stroke
*/
public BasicStroke getStroke() {
return stroke;
}
/**
* @param stroke 要设置的 stroke
*/
public void setStroke(BasicStroke stroke) {
this.stroke = stroke;
}
/**
* 设置画笔粗细
* @param width
*/
public void setStroke(float width) {
this.stroke = new BasicStroke(width, stroke.getEndCap(), stroke.getLineJoin());
}
/**
* 设置画笔端点的装饰
* @param cap 参考 java.awt.BasicStroke 类静态字段
*/
public void setStroke(int cap) {
this.stroke = new BasicStroke(stroke.getLineWidth(), cap, stroke.getLineJoin());
}
/**
* @return color
*/
public Color getColor() {
return color;
}
/**
* @param color 要设置的 color
*/
public void setColor(Color color) {
this.color = color;
}
public void mouseClicked(MouseEvent mouseEvent) {
}
/**
* 鼠标按下
*/
public void mousePressed(MouseEvent mouseEvent) {
this.oldMouseX = this.mouseX = mouseEvent.getX();
this.oldMouseY = this.mouseY = mouseEvent.getY();
repaint();
}
public void mouseReleased(MouseEvent mouseEvent) {
}
/**
* 鼠标进入棋盘
*/
public void mouseEntered(MouseEvent mouseEvent) {
this.setCursor(new Cursor(Cursor.CROSSHAIR_CURSOR));
}
/**
* 鼠标退出棋盘
*/
public void mouseExited(MouseEvent mouseEvent) {
this.setCursor(new Cursor(Cursor.DEFAULT_CURSOR));
}
/**
* 鼠标拖动
*/
public void mouseDragged(MouseEvent mouseEvent) {
this.oldMouseX = this.mouseX;
this.oldMouseY = this.mouseY;
this.mouseX = mouseEvent.getX();
this.mouseY = mouseEvent.getY();
repaint();
}
public void mouseMoved(MouseEvent mouseEvent) {
}
}
2024-03-02 02:58:47
2024-01-01 09:58:48
2024-04-13 00:38:12
2024-03-31 15:14:06
2024-03-21 00:22:13
2024-02-10 22:15:59