图片查看器java注解，有旋转功能

以下是一个使用Java注解实现图片旋转功能的示例代码：

import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.SwingConstants;

public class ImageRotator {

    private static final int ROTATION_ANGLE = 90;

    public static void main(String[] args) throws IOException {
        File file = new File("image.jpg");
        BufferedImage image = ImageIO.read(file);
        BufferedImage rotatedImage = rotate(image, ROTATION_ANGLE);
        displayImage(rotatedImage);
    }

    @ImageRotation(angle = ROTATION_ANGLE)
    private static BufferedImage rotate(BufferedImage image, int angle) {
        double radians = Math.toRadians(angle);
        int width = image.getWidth();
        int height = image.getHeight();
        int rotatedWidth = (int) Math.round(width * Math.abs(Math.cos(radians)) + height * Math.abs(Math.sin(radians)));
        int rotatedHeight = (int) Math.round(height * Math.abs(Math.cos(radians)) + width * Math.abs(Math.sin(radians)));
        BufferedImage rotatedImage = new BufferedImage(rotatedWidth, rotatedHeight, image.getType());
        Graphics2D graphics = rotatedImage.createGraphics();
        graphics.setTransform(getTransform(width, height, angle));
        graphics.drawImage(image, 0, 0, null);
        graphics.dispose();
        return rotatedImage;
    }

    private static AffineTransform getTransform(int width, int height, int angle) {
        AffineTransform transform = new AffineTransform();
        transform.translate(width / 2, height / 2);
        transform.rotate(Math.toRadians(angle));
        transform.translate(-height / 2, -width / 2);
        return transform;
    }

    private static void displayImage(BufferedImage image) {
        JFrame frame = new JFrame();
        JLabel label = new JLabel(new ImageIcon(image), SwingConstants.CENTER);
        frame.getContentPane().add(label);
        frame.pack();
        frame.setVisible(true);
    }
}

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD)
@interface ImageRotation {
    int angle();
}

在上面的示例中，我们定义了一个名为`ImageRotation`的注解，该注解可以应用于`rotate`方法上，用于指定旋转角度。当我们调用`rotate`方法时，程序会检查该方法上是否有`ImageRotation`注解，如果有，则从注解中获取旋转角度。程序使用Java的内置`AffineTransform`类来执行图像旋转操作，然后将旋转后的图像显示在窗口中。