如何获得图像的高度和宽度？

使用ImageIO.read(URL)或ImageIO.read(File)代替。加载时它将阻塞，返回后将知道图像的宽度和高度。

例如

import java.awt.image.BufferedImage;import javax.swing.*;import javax.imageio.ImageIO;import java.net.URL;class SizeOfImage {    public static void main(String[] args) throws Exception {        URL url = new URL("https://i.stack.imgur.com/7bI1Y.jpg");        final BufferedImage bi = ImageIO.read(url);        final String size = bi.getWidth() + "x" + bi.getHeight();        SwingUtilities.invokeLater(new Runnable() { public void run() {     JLabel l = new JLabel(          size,          new ImageIcon(bi),          SwingConstants.RIGHT );     JOptionPane.showMessageDialog(null, l); }        });    }}

或者，MediaTracker向由异步加载的映像中添加A ，Toolkit然后等待其完全加载。