问用Java压缩图像大小

EN

    BufferedImage bufferedImage = ImageIO.read(inputStream);
    ByteArrayOutputStream outputStream = new ByteArrayOutputStream();

    switch (imageType) {
        case PNG:
        case JPG:
            // need Java 9+ for PNG writer support
            ImageWriter writer = ImageIO.getImageWritersByFormatName(imageType.getExtension()).next();
            ImageOutputStream ios = ImageIO.createImageOutputStream(outputStream);
            writer.setOutput(ios);

            ImageWriteParam param = writer.getDefaultWriteParam();
            if (param.canWriteCompressed()) {
                param.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);
                param.setCompressionQuality(0.3f);
            }

            writer.write(null, new IIOImage(bufferedImage, null, null), param);
            writer.dispose();
            return new ByteArrayInputStream(outputStream.toByteArray());
        default:
            log.warn("Image type unknown");
            return null;
    }