Android开发：图片处理工具类

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.media.ExifInterface;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;

/**
 * 描述:图片工具类
 */

public class BitmapUtil {
    private static String PHOTO_FILE_NAME = "WSLManagerPhoto";

    /**
     * 获取图片的旋转角度
     *
     * @param filePath
     * @return
     */
    public static int getRotateAngle(String filePath) {
        int rotate_angle = 0;
        try {
            ExifInterface exifInterface = new ExifInterface(filePath);
            int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
            switch (orientation) {
                case ExifInterface.ORIENTATION_ROTATE_90:
                    rotate_angl