JAVA后台处理解决苹果手机IOS上传图片旋转90度问题

在做项目的时候遇到问题，通过苹果手机iphone(IOS)上传图片到服务器,后端得到的图片不是正常的。于是找到一个工具类，依赖我的业务进行简单的处理，记录下来，在此与大家共享，以便需要用时可以直接拿来用，上干货。

/**

* @Author: guo

* @Description: Java处理ios图片旋转的问题

* @Date: 2019/5/6 11:56

* @Version: 1.0

*/

public class RotateUtil {

public static File getPicture(File file){

try {

BufferedImage src = getPicture(file);

BufferedImage bi = null;

if(src != null){

int angel = getRotateAngle(file);//得到图片旋转角度

if(angel == 0){

bi = file;//图片正常直接返回

}else{

int srcWidth = src.getWidth(null);

int srcHeight = src.getHeight(null);

Rectangle rectangle = getRotatedSize(new Rectangle(new Dimension(srcWidth, srcHeight)), angel);

bi = new BufferedImage(rectangle.width, rectangle.height,BufferedImage.TYPE_INT_RGB);

Graphics2D g2 = bi.createGraphics();

g2.translate((rectangle.width - srcWidth) / 2,

(rectangle.height - srcHeight) / 2);

g2.rotate(Math.toRadians(angel), srcWidth / 2, srcHeight / 2);

g2.drawImage(src, null, null);

}

int index = file.getName().lastIndexOf(".");

String formate = file.getName().substring(index+1);

ImageIO.write(bi, formate, file);

return file;

}

} catch (Exception e) {

e.printStackTrace();

}

return null;

}

/**

* 读取图片文件

*/

public static BufferedImage getPicture(File file) {

BufferedImage bi = null;

try{

if(!file.exists()){

return null;

}

bi = ImageIO.read(file);

} catch (Exception e){

e.printStackTrace();

}

return bi;

}

/**

* 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 iterable = metadata.getDirectories();

for (Iterator iter = iterable.iterator(); iter.hasNext(); ) {

Directory dr = iter.next();

if (dr.getString(ExifIFD0Directory.TAG_ORIENTATION) != null) {

orientation = dr.getInt(ExifIFD0Directory.TAG_ORIENTATION);

}

/*Collection tags = dr.getTags();

for (Tag tag : tags) {

System.out.println(tag.getTagName() + "： " + tag.getDescription());

}*/

}

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;

}

/**

* 计算旋转参数

*/

public static Rectangle getRotatedSize(Rectangle src,int angel){

// if angel is greater than 90 degree,we need to do some conversion.

if(angel > 90){

if(angel / 9%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 angelAlpha = (Math.PI - Math.toRadians(angel)) / 2;

double angelDaltaWidth = Math.atan((double) src.height / src.width);

double angeDaltaHeight = Math.atan((double) src.width / src.height);

int lenDaltaWidth = (int) (len * Math.cos(Math.PI - angelAlpha

- angelDaltaWidth));

int lenDaltaHeight = (int) (len * Math.cos(Math.PI - angelAlpha

- angeDaltaHeight));

int desWidth = src.width + lenDaltaWidth * 2;

int desHeight = src.height + lenDaltaHeight * 2;

return new Rectangle(new Dimension(desWidth, desHeight));

}

}

至此，JAVA WEB后台就处理解决了苹果手机IOS上传图片旋转90度的问题。