ImageIO.wtrie生成jpg图片质量损失方案：BufferedImage生成jpg图片文件流

　　　　 Iterator<ImageWriter> iterator = ImageIO.getImageWritersByFormatName("jpeg");

        ImageWriter imageWriter = iterator.next();

        ImageWriteParam imageWriteParam = imageWriter.getDefaultWriteParam();

        imageWriteParam.setCompressionMode(ImageWriteParam.MODE_EXPLICIT);

        imageWriteParam.setCompressionQuality(1);

        imageWriter.setOutput(imageOutput);

        IIOImage iio_image = new IIOImage(image, null, null);

        imageWriter.write(null, iio_image, imageWriteParam);

        imageWriter.dispose();