java ImageIO.write图片上传变色及背景变黑解决

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java ImageIO.write图片上传变色及背景变黑解决

public void getImage(HttpServletRequest request, HttpServletResponse response) throws Exception {response.setDateHeader("Expires", 0);response.setHeader("Cache-Control", "no-store, no-cache, must-revalidate");response.addHeader("Cache-Control", "post-check=0, pre-check=0");response.setHeader("Pragma", "no-cache");response.setContentType("image/jpeg");String uri = request.getRequestURI();String imgPath = uri.replace("/ofc/rest/img", "");File image = new File(imgPath);BufferedImage bi = ImageIO.read(image);BufferedImage newBi = resizeImagePng(bi.getWidth(), bi.getHeight(),bi);Graphics2D g2d = newBi.createGraphics();g2d.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_ATOP, 1.0f));ServletOutputStream out = response.getOutputStream();g2d.drawImage(newBi,0,0,null);ImageIO.write(newBi,"png", out);//ImageIO.write(bi, "jpg", out);//saveAs(bi,"jpg", out);}

public static BufferedImage resizeImagePng(int x, int y, BufferedImage bfi) {BufferedImage bufferedImage = new BufferedImage(x, y, BufferedImage.TYPE_INT_ARGB);bufferedImage.getGraphics().drawImage(bfi.getScaledInstance(x, y, Image.SCALE_SMOOTH), 0, 0, null);return bufferedImage;}

public static void saveAs(BufferedImage image, String formatName, ServletOutputStream outFile) throws IOException {if (formatName.equalsIgnoreCase("jpg") || formatName.equalsIgnoreCase("jpeg")) {BufferedImage tag = new BufferedImage(image.getWidth(), image.getHeight(), BufferedImage.TYPE_INT_BGR);Graphics g = tag.getGraphics();//            Graphics2D gg=tag.createGraphics();
//            tag = gg.getDeviceConfiguration().createCompatibleImage(image.getWidth(), image.getHeight(),Transparency.TRANSLUCENT);
//            gg.dispose();
//            gg = tag.createGraphics();
//            gg.drawImage(image, 0, 0,null);g.drawImage(image, 0, 0,image.getWidth(), image.getHeight(),image.getGraphics().getColor(), null); // 绘制缩小后的图g.dispose();image = tag;}ImageIO.write(image, formatName, outFile);}