java - JAVA 中 JPG 图像大小调整程序的 0 字节文件

Question

我在使用以下代码调整图像(JPG 文件)大小时遇到​​问题:

import java.awt.AlphaComposite;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.image.BufferedImage;
import java.io.File;
import java.util.logging.Logger;
import java.util.logging.Level;
import java.io.IOException;
import javax.imageio.ImageIO;

public class ResizeImage {


    /**
     * 
     * @param sourceImg
     *            The source of the image to resize.
     * @param Width
     *            The maximum width you want the new image to be, use 0 for
     *            source width.
     * @param Height
     *            The maximum height you want the new image to be, use 0 for
     *            source height.
     * @return true if successful and false if unsuccessful.
     */

    public static String resizeImage(String sourceImg, Integer Width,
            Integer Height) {

        BufferedImage origImage;
        BufferedImage resizedImage = null;
        // String tDir = System.getProperty("java.io.tmpdir");
        String imagePath;

        try {

            File resizedFile = File.createTempFile("ResizedImmoIMG", ".jpg");
            imagePath = resizedFile.getAbsolutePath();
            origImage = ImageIO.read(new File(sourceImg));
            int type = origImage.getType() == 0 ? BufferedImage.TYPE_INT_ARGB
                    : origImage.getType();

            // *Special* if the width or height is 0 use image src dimensions
            if (Width == 0) {
                Width = origImage.getWidth();
            }
            if (Height == 0) {
                Height = origImage.getHeight();
            }

            int fHeight = Height;
            int fWidth = Width;

            // Work out the resized width/height
            if (origImage.getHeight() > Height || origImage.getWidth() > Width) {
                fHeight = Height;
                int wid = Width;
                float sum = (float) origImage.getWidth()
                        / (float) origImage.getHeight();
                fWidth = Math.round(fHeight * sum);

                if (fWidth > wid) {
                    // rezise again for the width this time
                    fHeight = Math.round(wid / sum);
                    fWidth = wid;
                }
            }

            resizedImage = new BufferedImage(fWidth, fHeight, type);

            Graphics2D g2d = resizedImage.createGraphics();
            g2d.setComposite(AlphaComposite.Src);

            g2d.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
                    RenderingHints.VALUE_INTERPOLATION_BILINEAR);
            g2d.setRenderingHint(RenderingHints.KEY_RENDERING,
                    RenderingHints.VALUE_RENDER_QUALITY);
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);

            g2d.drawImage(origImage, 0, 0, fWidth, fHeight, null);
            g2d.dispose();

            ImageIO.write(resizedImage, ".jpg", resizedFile);
            System.out.println(imagePath);

        } catch (IOException ex) {
            Logger.getLogger(ResizeImage.class.getName()).log(Level.SEVERE,
                    null, ex);
            return null;
        }
        return imagePath;
    }

   }

程序应该调整源图像的大小，并将其保存在系统临时目录中。但我得到的只是临时目录中的 0 字节 JPG 文件。我看不出我哪里做错了:(

有人可以给我一些建议或提示吗？

问候

THE-E

Answer 1

作为 ImageIO.write 方法的第二个参数，您必须传递图像格式而不是文件扩展名。尝试简单地使用“jpg”而不是“.jpg”。

Writing/Saving an Image