前端H5、IOS、Android端，照片前端，後端旋轉並調正

參考資料：https://www.jianshu.com/p/ad4501db178e/

                 https://github.com/think2011/localResizeIMG

前端圖片校準：

這裏貼出我使用的前端js,需要引入js

<script type="text/javascript" src="redsize/dist/lrz.bundle.js"></script>

//source是我前端進來的圖片資源
var file = source.files[0];
lrz(file).then(function (rst) {
            // 處理成功會執行
			//res=rst;
            //console.log(rst);
//            console.log(rst.base64);
        })
        .catch(function (err) {
            // 處理失敗會執行
        })
        .always(function () {
            // 不管是成功失敗，都會執行
        });

下面貼出需要的js下載地址：https://download.csdn.net/download/weixin_42102798/12026883

後端圖片校準：

 前端不保證完全都能成功，我嘗試了一些，有些手機不行。比如手機把攝像頭全部倒過來拍一張（人臉向下），發送倒服務器。發現服務器接收的是向右歪的（人臉向右）。前端好的，可以研究一下exif.js 源碼。

保證決定性，所以後端也有調整歪斜圖片，代碼如下：

第一種方式：

import com.drew.imaging.ImageMetadataReader;
import com.drew.metadata.Directory;
import com.drew.metadata.Metadata;
import com.drew.metadata.exif.ExifIFD0Directory;
import com.sun.image.codec.jpeg.ImageFormatException;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGEncodeParam;
import com.sun.image.codec.jpeg.JPEGImageEncoder;

import javax.imageio.ImageIO;
import java.awt.*;
import java.awt.image.BufferedImage;
import java.io.*;
import java.nio.channels.FileChannel;
import java.util.Iterator;

/**
 * 圖片旋轉工具類
 */
public class PicUtil {

    public static void main(String args[]) {
        String src = "C:/Users/Administrator/Desktop/5.jpg";
        //獲取圖片旋轉角度
        int angel = getRotateAngleForPhoto(src);
        System.out.println(">>>>>>>>>>>" + angel);
        if (angel > 0) {
            rotateImage(new File(src), angel);
        }
    }

    /**
     * 判斷圖片是否需要旋轉
     */
    public static void judgeRotate(String fileName) {
        //獲取圖片旋轉角度
        int angel = getRotateAngleForPhoto(fileName);
        if (angel > 0 && angel < 360) {
            rotateImage(new File(fileName), angel);
        }
    }

    /**
     * 圖片翻轉時，計算圖片翻轉到正常顯示需旋轉角度
     */
    public static int getRotateAngleForPhoto(String fileName) {
        File file = new File(fileName);
        int angel = 0;
        try {
            //核心對象操作對象
            Metadata metadata = ImageMetadataReader.readMetadata(file);
            //獲取所有不同類型的Directory，如ExifSubIFDDirectory, ExifInteropDirectory, ExifThumbnailDirectory等，這些類均爲ExifDirectoryBase extends Directory子類
            //分別遍歷每一個Directory，根據Directory的Tags就可以讀取到相應的信息
            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());
            }*/
            }
            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;
    }

    /**
     * 旋轉圖片爲指定角度
     *
     * @param file  目標圖像
     * @param angel 旋轉角度
     * @return
     */
    public static File rotateImage(File file, final int angel) {
        BufferedImage src = null;
        try {
            src = ImageIO.read(file);
        } catch (IOException e) {
            e.printStackTrace();
        }
        int src_width = src.getWidth(null);
        int src_height = src.getHeight(null);
        Rectangle rect_des = calcRotatedSize(new Rectangle(new Dimension(src_width, src_height)), angel);

        BufferedImage bi = new BufferedImage(rect_des.width, rect_des.height, BufferedImage.TYPE_INT_RGB);
        Graphics2D g2 = bi.createGraphics();

        g2.translate((rect_des.width - src_width) / 2, (rect_des.height - src_height) / 2);
        g2.rotate(Math.toRadians(angel), src_width / 2, src_height / 2);

        g2.drawImage(src, null, null);
        try {
            ImageIO.write(bi, "jpg", file);
        } catch (IOException e) {
            e.printStackTrace();
        }
        // 調用方法輸出圖片文件
        // outImage(file.getPath(), bi, (float) 0.5);
        return file;
    }

    /**
     * 計算旋轉參數
     */
    public static Rectangle calcRotatedSize(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 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));
    }

    /**
     * 將圖片文件輸出到指定的路徑，並可設定壓縮質量
     *
     * @param outImgPath
     * @param newImg
     * @param quality
     */
    private static void outImage(String outImgPath, BufferedImage newImg, float quality) {
        // 判斷輸出的文件夾路徑是否存在，不存在則創建
        File file = new File(outImgPath);
        if (!file.getParentFile().exists()) {
            file.getParentFile().mkdirs();
        }
        // 輸出到文件流
        FileChannel fc = null;
        try {
            FileOutputStream newimage = new FileOutputStream(outImgPath);
            //獲取圖片大小
            fc = newimage.getChannel();
            //1M
            if (fc.size() > 1 * 1024 * 1024) {
                quality = (float) (1 * 1024 * 1024.00 / fc.size() * 0.5);
            }

            JPEGImageEncoder encoder = JPEGCodec.createJPEGEncoder(newimage);
            JPEGEncodeParam jep = JPEGCodec.getDefaultJPEGEncodeParam(newImg);
            // 壓縮質量
            jep.setQuality(quality, true);
            encoder.encode(newImg, jep);
            newimage.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (ImageFormatException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    /**
     * * 圖片文件讀取
     *
     * @param srcImgPath
     * @return
     */
    public static BufferedImage inputImage(String srcImgPath) {
        BufferedImage srcImage = null;
        File file = new File(srcImgPath);
        try {
            // 構造BufferedImage對象
            FileInputStream in = new FileInputStream(file);
            byte[] b = new byte[5];
            in.read(b);
            srcImage = ImageIO.read(file);
        } catch (IOException e) {
            System.out.println("讀取圖片文件出錯！" + e.getMessage());
            e.printStackTrace();
        }
        return srcImage;
    }
}

所需要的maven依賴：

<dependency>
    <groupId>com.drewnoakes</groupId>
    <artifactId>metadata-extractor</artifactId>
    <version>2.11.0</version>
</dependency>

第二種方式：

import javax.imageio.ImageIO;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.File;

/**
 * Created with IDEA
 * author:Jy
 * Date:2019/12/11
 * Time:9:21
 */
public class IMGTest {

    public static int getJpegOrientation(int naturalJpegOrientation, int deviceOrientation) {
        return (naturalJpegOrientation+ deviceOrientation) % 360;
    }

    static byte[] bytes;

    public static void main(String[] args){
        String src = "C:/Users/Administrator/Desktop/5.jpg";
        File file = new File(src);
        fileToByte(file);
        //System.out.println(bytes.length);
        int reg = getNaturalOrientation(bytes);
        System.out.println("需要旋轉的角度："+reg);
    }
    /**
     * 圖片轉byte[]
     * @return
     */
    public static byte[] fileToByte(File img){
        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try {
            BufferedImage bi;
            bi = ImageIO.read(img);
            ImageIO.write(bi, "jpg", baos);
            bytes = baos.toByteArray();
            System.err.println(bytes.length);
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (baos != null){
                try {
                    baos.close();
                } catch (Exception ex){
                    ex.printStackTrace();
                }
            }
        }
        return bytes;
    }
    /**
     * 從底層返回的數據拿到對應的圖片的角度，有些手機hal層會對手機拍出來的照片作相應的旋轉，有些手機不會(比如三星手機)
     * @param jpeg
     * @return
     */
    public static int getNaturalOrientation(byte[] jpeg) {
        if (jpeg == null) {
            return 0;
        }

        int offset = 0;
        int length = 0;

        // ISO/IEC 10918-1:1993(E)
        while (offset + 3 < jpeg.length && (jpeg[offset++] & 0xFF) == 0xFF) {
            int marker = jpeg[offset] & 0xFF;

            // Check if the marker is a padding.
            if (marker == 0xFF) {
                continue;
            }
            offset++;

            // Check if the marker is SOI or TEM.
            if (marker == 0xD8 || marker == 0x01) {
                continue;
            }
            // Check if the marker is EOI or SOS.
            if (marker == 0xD9 || marker == 0xDA) {
                break;
            }

            // Get the length and check if it is reasonable.
            length = pack(jpeg, offset, 2, false);
            if (length < 2 || offset + length > jpeg.length) {
                System.out.println( "Invalid length");
                return 0;
            }

            // Break if the marker is EXIF in APP1.
            if (marker == 0xE1 && length >= 8 &&
                    pack(jpeg, offset + 2, 4, false) == 0x45786966 &&
                    pack(jpeg, offset + 6, 2, false) == 0) {
                offset += 8;
                length -= 8;
                break;
            }

            // Skip other markers.
            offset += length;
            length = 0;
        }

        // JEITA CP-3451 Exif Version 2.2
        if (length > 8) {
            // Identify the byte order.
            int tag = pack(jpeg, offset, 4, false);
            if (tag != 0x49492A00 && tag != 0x4D4D002A) {
                System.out.println( "Invalid byte order");
                return 0;
            }
            boolean littleEndian = (tag == 0x49492A00);

            // Get the offset and check if it is reasonable.
            int count = pack(jpeg, offset + 4, 4, littleEndian) + 2;
            if (count < 10 || count > length) {
                System.out.println( "Invalid offset");
                return 0;
            }
            offset += count;
            length -= count;

            // Get the count and go through all the elements.
            count = pack(jpeg, offset - 2, 2, littleEndian);
            while (count-- > 0 && length >= 12) {
                // Get the tag and check if it is orientation.
                tag = pack(jpeg, offset, 2, littleEndian);
                if (tag == 0x0112) {
                    // We do not really care about type and count, do we?
                    int orientation = pack(jpeg, offset + 8, 2, littleEndian);
                    System.out.println(orientation);
                    switch (orientation) {
                        case 1:
                            return 0;
                        case 3:
                            return 180;
                        case 6:
                            return 90;
                        case 8:
                            return 270;
                    }
                    System.out.println( "Unsupported orientation");
                    return 0;
                }
                offset += 12;
                length -= 12;
            }
        }
        return 0;
    }

    private static int pack(byte[] bytes, int offset, int length,
                            boolean littleEndian) {
        int step = 1;
        if (littleEndian) {
            offset += length - 1;
            step = -1;
        }

        int value = 0;
        while (length-- > 0) {
            value = (value << 8) | (bytes[offset] & 0xFF);
            offset += step;
        }
        return value;
    }

}