java将指定文件夹下面的所有图片压缩到指定大小以内并保存图片
参考：https://blog.csdn.net/goxingman/article/details/126172320
https://blog.csdn.net/luChenH/article/details/89558707
public void covert() { //File file = new File("D:\\data\\apache-tomcat-yyshop\\file"); File file = new File(SysConfig.getProfile()); fileDird(file); } /** * 遍历指定文件下的所有文件，包括目录中的文件 */ public static void fileDird(File file) { File[] fs = file.listFiles(); for (File f : fs) { if (f.isDirectory()) { //若是目录，则递归打印该目录下的文件 fileDird(f); } else if (f.isFile() && isImage(f)) { //若是图片文件 log.info(f.getAbsolutePath()); //若是文件则进行压缩 saveFile(f.getAbsolutePath()); } } }
工具类
@Slf4j public class ImageUtils { public static MultipartFile base64ToMultipartFile(String base64) { //base64编码后的图片有头信息所以要分离出来 [0]data:image/png;base64, 图片内容为索引[1] String[] baseStrs = base64.split(","); //取索引为1的元素进行处理 byte[] b = Base64.decodeBase64(baseStrs[1]); for (int i = 0; i < b.length; ++i) { if (b[i] < 0) { b[i] += 256; } } //处理过后的数据通过Base64DecodeMultipartFile转换为MultipartFile对象 return new Base64DecodeMultipartFile(b, baseStrs[0]); } /** * 通过BufferedImage图片流调整图片大小 * 指定压缩后长宽 */ public static BufferedImage resizeImage(BufferedImage originalImage, int targetWidth, int targetHeight) throws IOException { Image resultingImage = originalImage.getScaledInstance(targetWidth, targetHeight, Image.SCALE_AREA_AVERAGING); BufferedImage outputImage = new BufferedImage(targetWidth, targetHeight, BufferedImage.TYPE_INT_RGB); outputImage.getGraphics().drawImage(resultingImage, 0, 0, null); return outputImage; } /** * 通过BufferedImage图片流调整图片大小 * @param originalImage * @param reduceMultiple 缩小倍数 * @return * @throws IOException */ public static BufferedImage resizeImage(BufferedImage originalImage, float reduceMultiple) throws IOException { int width = (int) (originalImage.getWidth() * reduceMultiple); int height = (int) (originalImage.getHeight() * reduceMultiple); Image resultingImage = originalImage.getScaledInstance(width, height, Image.SCALE_AREA_AVERAGING); BufferedImage outputImage = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); outputImage.getGraphics().drawImage(resultingImage, 0, 0, null); return outputImage; } /** * 压缩图片到指定大小 * @param srcImgData * @param reduceMultiple 每次压缩比率 * @return * @throws IOException */ public static byte[] resizeImage(byte[] srcImgData, float reduceMultiple) throws IOException { BufferedImage bi = ImageIO.read(new ByteArrayInputStream(srcImgData)); int width = (int) (bi.getWidth() * reduceMultiple); // 源图宽度 int height = (int) (bi.getHeight() * reduceMultiple); // 源图高度 Image image = bi.getScaledInstance(width, height, Image.SCALE_SMOOTH); BufferedImage tag = new BufferedImage(width, height, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.setColor(Color.RED); g.drawImage(image, 0, 0, null); // 绘制处理后的图 g.dispose(); ByteArrayOutputStream bOut = new ByteArrayOutputStream(); ImageIO.write(tag, "JPEG", bOut); return bOut.toByteArray(); } /** * BufferedImage图片流转byte[]数组 */ public static byte[] imageToBytes(BufferedImage bImage) { ByteArrayOutputStream out = new ByteArrayOutputStream(); try { ImageIO.write(bImage, "jpg", out); } catch (IOException e) { e.printStackTrace(); } return out.toByteArray(); } /** * byte[]数组转BufferedImage图片流 */ private static BufferedImage bytesToBufferedImage(byte[] ImageByte) { ByteArrayInputStream in = new ByteArrayInputStream(ImageByte); BufferedImage image = null; try { image = ImageIO.read(in); } catch (IOException e) { e.printStackTrace(); } return image; } /** * 判断文件大小处于限制内 * * @param fileLen 文件长度 * @param fileSize 限制大小 * @param fileUnit 限制的单位（B,K,M,G） * @return */ public static boolean checkFileSizeIsLimit(Long fileLen, int fileSize, String fileUnit) { // long len = file.length(); double fileSizeCom = 0; if ("B".equals(fileUnit.toUpperCase())) { fileSizeCom = (double) fileLen; } else if ("K".equals(fileUnit.toUpperCase())) { fileSizeCom = (double) fileLen / 1024; } else if ("M".equals(fileUnit.toUpperCase())) { fileSizeCom = (double) fileLen / (1024*1024); } else if ("G".equals(fileUnit.toUpperCase())) { fileSizeCom = (double) fileLen / (1024*1024*1024); } if (fileSizeCom > fileSize) { return false; } return true; } /** * file转multipartFile * @param file * @return */ public static MultipartFile fileToMultipartFile(File file) { log.info("fileToMultipartFile文件转换中："+file.getAbsolutePath()); FileItemFactory factory = new DiskFileItemFactory(16, null); FileItem item=factory.createItem(file.getName(),"text/plain",true,file.getName()); int bytesRead = 0; byte[] buffer = new byte[8192]; try { FileInputStream fis = new FileInputStream(file); OutputStream os = item.getOutputStream(); while ((bytesRead = fis.read(buffer, 0, 8192)) != -1) { os.write(buffer, 0, bytesRead); } os.close(); fis.close(); } catch (IOException e) { e.printStackTrace(); } return new CommonsMultipartFile(item); } }
判断文件是否是图片，仅压缩图片
public static String getFileSuffix(File file) { if (file == null) { return null; } String suffix = null; String fileName = file.getName(); if (fileName.lastIndexOf(".") != -1 && fileName.lastIndexOf(".") != 0) { suffix = fileName.substring(fileName.lastIndexOf(".") + 1); } return suffix; }
// public static boolean isImage(File file) { boolean result = false; //是否是图片 List<String> imgs = new ArrayList<String>() {{ this.add("JPEG"); this.add("JPG"); this.add("GIF"); this.add("BMP"); this.add("PNG"); }}; if (imgs.contains(getFileSuffix(file).toUpperCase())) { result = true; } return result; }
调用方法
/** * 保存照片文件 * * @param path 文件绝对路径 */ public static void saveFile(String path){ try { File fileInit = new File(path); if (fileInit.exists()){ MultipartFile file =fileToMultipartFile(fileInit); log.info("file转multipartFile成功. {}", file); if (!checkFileSizeIsLimit(file.getSize(),200,"K")){ if (file != null && !file.isEmpty()) { //保存文件到对应位置 File dir = new File(path); if (!dir.getParentFile().exists()) { dir.getParentFile().mkdirs(); } // 压缩到小于指定文件大小200k double targetSize = 200 * 1024; //从MultipartFile 中获取 byte[] byte[] bytes = file.getBytes(); log.info("头像图片压缩前大小：[{}]", bytes.length); while (bytes.length > targetSize) { float reduceMultiple = 0.5f; bytes = resizeImage(bytes, reduceMultiple); } log.info("头像图片压缩后大小：[{}]", bytes.length); BufferedImage newImage = bytesToBufferedImage(bytes); //图像缓冲区图片保存为图片文件(文件不存在会自动创建文件保存，文件存在会覆盖原文件保存) ImageIO.write(newImage, "jpg", new File(path)); } } } } catch (IOException e) { //抛出异常 log.info("图片压缩出错"); } }
