IOS设备上传图片，使用ImageIO.write 图片翻转纠正（JAVA）

  在使用ios设备时，上传图片，发现图片旋转了90度。

 

正确：

 

错误：

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1. 引入pom

在pom.xml中引入需要的依赖内容：

 

        <dependency>
            <groupId>com.drewnoakes</groupId>
            <artifactId>metadata-extractor</artifactId>
            <version>2.7.0</version>
        </dependency>

 

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2. 计算图片翻转到正常显示需旋转的角度数

　　/**
     * 计算图片翻转到正常显示需旋转角度
     */
    public static int getRotateAngle(File file) {

        int angel = 0;
        Metadata metadata = null;
        try {
            metadata = ImageMetadataReader.readMetadata(file);
            int orientation = 0;
            Iterable<Directory> iterable = metadata.getDirectories();

            for (Iterator<Directory> iter = iterable.iterator(); iter.hasNext(); ) {
                Directory dr = iter.next();
                if (dr.getString(ExifIFD0Directory.TAG_ORIENTATION) != null) {
                    orientation = dr.getInt(ExifIFD0Directory.TAG_ORIENTATION);
                }
                Collection<Tag> tags = dr.getTags();
                for (Tag tag : tags) {
                    System.out.println(tag.getTagName() + "： " + tag.getDescription());
                }
            }
            System.out.println("orientation::::" + orientation);
            if (orientation == 0 || orientation == 1) {
                angel = 360;
            } else if (orientation == 3) {
                angel = 180;
            } else if (orientation == 6) {
                angel = 90;
            } else if (orientation == 8) {
                angel = 270;
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return angel;
    }

 

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3. 旋转图片-指定度数

 

/**
     * 旋转图片
     */
    public static BufferedImage rotateImage(BufferedImage bufferedImage, int angel) {
        if (bufferedImage == null) {
            return null;
        }
        if (angel < 0) {
            // 将负数角度，纠正为正数角度
            angel = angel + 360;
        }
        int imageWidth = bufferedImage.getWidth(null);
        int imageHeight = bufferedImage.getHeight(null);
        // 计算重新绘制图片的尺寸
        Rectangle rectangle = calculatorRotatedSize(new Rectangle(new Dimension(imageWidth, imageHeight)), angel);
        // 获取原始图片的透明度
        int type = bufferedImage.getColorModel().getTransparency();
        BufferedImage newImage = null;
        newImage = new BufferedImage(rectangle.width, rectangle.height, type);
        Graphics2D graphics = newImage.createGraphics();
        // 平移位置
        graphics.translate((rectangle.width - imageWidth) / 2, (rectangle.height - imageHeight) / 2);
        // 旋转角度
        graphics.rotate(Math.toRadians(angel), imageWidth / 2, imageHeight / 2);
        // 绘图
        graphics.drawImage(bufferedImage, null, null);
        return newImage;
    }

 

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将图片保存到本地：

private InputStream savePic(InputStream inputStream, String path) {

        OutputStream os = null;
        try {
            // 2、保存到临时文件
            // 1K的数据缓冲
            byte[] bs = new byte[1024];
            // 读取到的数据长度
            int len;
            // 输出的文件流保存到本地文件
            os = new FileOutputStream(path);
            // 开始读取
            while ((len = inputStream.read(bs)) != -1) {
                os.write(bs, 0, len);
            }
            InputStream input = new FileInputStream(path);
            return input;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            // 完毕，关闭所有链接
            try {
                os.close();
                inputStream.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
        return null;
    }

 

 

/**
     * 计算旋转后的尺寸
     * 
     * @param src
     * @param angel
     * @return
     */
    private static Rectangle calculatorRotatedSize(Rectangle src, int angel) {
        if (angel >= 90) {
            if (angel / 90 % 2 == 1) {
                int temp = src.height;
                src.height = src.width;
                src.width = temp;
            }
            angel = angel % 90;
        }
        double r = Math.sqrt(src.height * src.height + src.width * src.width) / 2;
        double len = 2 * Math.sin(Math.toRadians(angel) / 2) * r;
        double angel_alpha = (Math.PI - Math.toRadians(angel)) / 2;
        double angel_dalta_width = Math.atan((double) src.height / src.width);
        double angel_dalta_height = Math.atan((double) src.width / src.height);

        int len_dalta_width = (int) (len * Math.cos(Math.PI - angel_alpha - angel_dalta_width));
        int len_dalta_height = (int) (len * Math.cos(Math.PI - angel_alpha - angel_dalta_height));
        int des_width = src.width + len_dalta_width * 2;
        int des_height = src.height + len_dalta_height * 2;
        return new java.awt.Rectangle(new Dimension(des_width, des_height));
    }

 

 注：需将图片正常保存到本地，然后使用 getRotateAngle 方法获取需要旋转到角度

 

//先把图片存到本地
InputStream inputStream = savePic(file.getInputStream(),"/test/a.jpg");

//获取本地图片需要旋转到度数
int rotateAngle = getRotateAngle(new file("/test/a.jpg"));

//读取BuffereadImage.
BufferedImage bi = ImageIO.read(inputStream);
//如果需要旋转
if (rotateAngle != 0) {
　　//旋转
    bi = rotateImage(bi, rotateAngle);
}
//最后使用

ImageIO.write(bi, "jpg", file);