// 将图片文件转化为字节数组字符串，并对其进行Base64编码处理
//Base64所用包：org.apache.commons.codec.binary.Base64
public static String encodeImgageToBase64(File imageFile) {
byte[] data = null;
// 读取图片字节数组
try {
InputStream in = new FileInputStream(imageFile);
data = new byte[in.available()];
in.read(data);
in.close();
} catch (IOException e) {
e.printStackTrace();
}
// 对字节数组Base64编码
return Base64.encodeBase64String(data);// 返回Base64编码过的字节数组字符串
}
判断是否旋转：
/**
*
* @功能:解析base64图片编码，判断是否有旋转
* @param imgStr base64图片编码
* @param format 图片格式
* @param fileName 图片名称
*/
public static Map stringToImage(String imgStr, String format, String fileName){
//解码base64图片
byte[] bts = Base64.decodeBase64(imgStr);
InputStream is = new ByteArrayInputStream(bts);
try {
//获取照片的Exif信息
Metadata metadata = JpegMetadataReader.readMetadata(is);
Directory exif = metadata.getFirstDirectoryOfType(ExifDirectoryBase.class);
/*
//输出从图片获取到的相关信息
Iterable ites = metadata.getDirectories();
for (Directory directory : ites) {
Iterator tags = directory.getTags().iterator();
while(tags.hasNext()){
Tag tag = (Tag) tags.next();
System.out.println(tag);
}
}
*/
//获取照片拍摄方向
String type = exif.getString(ExifDirectoryBase.TAG_ORIENTATION);
//图片正常情况下，type=1,测试正常图片旋转，请修改case 条件为 1
if(StringUtil.notBlank(type)){//判断拍摄方向是否为空
switch (Integer.parseInt(type)) {
case 3://要进行180度旋转
byte[] bytes = rotateImg(bts , 180.0 , format);
return uploadToAliYunOSS(fileName, bytes);
case 6://要进行90度旋转
byte[] bytes1 = rotateImg(bts , 90.0 , format);
return uploadToAliYunOSS(fileName, bytes1);
case 8://要进行-90度旋转
byte[] bytes2 = rotateImg(bts , -90.0 , format);
return uploadToAliYunOSS(fileName, bytes2);
default :
return uploadToAliYunOSSBybase64(fileName, bts);
}
}else{
return uploadToAliYunOSSBybase64(fileName, bts);
}
} catch (Exception e) {
e.printStackTrace();
}
return Tool.getError(1, "请求错误！", "");
}
矫正图片旋转
/**
*
* @功能:矫正图片旋转，返回byte[]
* @param input
* @param angle
* @param format
* @param fileName
* @throws IOException void
*/
public static byte[] rotateImg(byte[] bytes , double angle , String format) throws IOException{
InputStream input = new ByteArrayInputStream(bytes);
BufferedImage old_img = ImageIO.read(input);
int width = old_img.getWidth();
int height = old_img.getHeight();
double[][] newPositions = new double[4][];
newPositions[0] = calculatePosition(0, 0, angle);
newPositions[1] = calculatePosition(width, 0, angle);
newPositions[2] = calculatePosition(0, height, angle);
newPositions[3] = calculatePosition(width, height, angle);
double minX = Math.min(
Math.min(newPositions[0][0], newPositions[1][0]),
Math.min(newPositions[2][0], newPositions[3][0])
);
double maxX = Math.max(
Math.max(newPositions[0][0], newPositions[1][0]),
Math.max(newPositions[2][0], newPositions[3][0])
);
double minY = Math.min(
Math.min(newPositions[0][1], newPositions[1][1]),
Math.min(newPositions[2][1], newPositions[3][1])
);
double maxY = Math.max(
Math.max(newPositions[0][1], newPositions[1][1]),
Math.max(newPositions[2][1], newPositions[3][1])
);
int newWidth = (int)Math.round(maxX - minX);
int newHeight = (int)Math.round(maxY - minY);
BufferedImage new_img = new BufferedImageBuilder(newWidth, newHeight , BufferedImage.TYPE_INT_BGR).build();
Graphics2D g = new_img.createGraphics();
g.setRenderingHint(
RenderingHints.KEY_INTERPOLATION,
RenderingHints.VALUE_INTERPOLATION_BILINEAR
);
g.setRenderingHint(
RenderingHints.KEY_ANTIALIASING,
RenderingHints.VALUE_ANTIALIAS_ON
);
double w = newWidth / 2.0;
double h = newHeight / 2.0;
g.rotate(Math.toRadians(angle), w, h);
int centerX = (int)Math.round((newWidth - width) / 2.0);
int centerY = (int)Math.round((newHeight - height) / 2.0);
g.drawImage(old_img, centerX, centerY, null);
g.dispose();
//新建流。
ByteArrayOutputStream baos = new ByteArrayOutputStream();
//利用ImageIO类的write方法，将BufferedImage以png图片的数据模式写入流。
ImageIO.write(new_img, format, baos);
return baos.toByteArray();
}
rotateImg() 中的calculatePosition()方法
private static double[] calculatePosition(double x, double y, double angle){
angle = Math.toRadians(angle);
double nx = (Math.cos(angle) * x) - (Math.sin(angle) * y);
double ny = (Math.sin(angle) * x) + (Math.cos(angle) * y);
return new double[] {nx, ny};
}
本文中的方法出处：http://my.oschina.net/u/2344340/blog/699435
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