private Bitmap getCompressedBitmap(Bitmap bitmap) {
       try {
           //创建一个用于存储压缩后Bitmap的文件
           File compressedFile = FileHelper.createFileByType(mContext, destType, "compressed");
           Uri uri = Uri.fromFile(compressedFile);
           OutputStream os = getContentResolver().openOutputStream(uri);
           Bitmap.CompressFormat format = destType == FileHelper.JPEG ?
                   Bitmap.CompressFormat.JPEG : Bitmap.CompressFormat.PNG;
	// >>>核心部分
           boolean success = bitmap.compress(format, 0, os);
	// <<<核心部分
           if (success) {
               T.showLToast(mContext, "success");
           }
           final String pathName = FileHelper.stripFileProtocol(uri.toString());
           showBitmapInfos(pathName);
           bitmap = BitmapFactory.decodeFile(pathName);
           os.close();
       } catch (FileNotFoundException e) {
           e.printStackTrace();
       } catch (IOException e) {
           e.printStackTrace();
       }
       return bitmap;
   }

private void CropTheImage(Uri imageUrl) {
       Intent cropIntent = new Intent("com.android.camera.action.CROP");
       cropIntent.setDataAndType(imageUrl, "image/*");
       cropIntent.putExtra("cropWidth", "true");
       cropIntent.putExtra("outputX", cropTargetWidth);
       cropIntent.putExtra("outputY", cropTargetHeight);

	//设置输出Uri
	if (Build.VERSION.SDK_INT > Build.VERSION_CODES.N) {
           File file = new File(mContext.getCacheDir(), "test1.jpg");
           copyUrl = Uri.fromFile(file);
           Uri contentUri = FileProvider.getUriForFile(this, getPackageName() + ".provider", file);
           cropIntent.putExtra("output", contentUri);
       } else {
           File copyFile = FileHelper.createFileByType(mContext, destType, String.valueOf(System.currentTimeMillis()));
           copyUrl = Uri.fromFile(copyFile);
           cropIntent.putExtra("output", copyUrl);
       }
       startActivityForResult(cropIntent, REQUEST_CODE_CROP_PIC);
   }

//FileHelper.java
public static File createFileByType(Context mContext, int type, String name) {
       if (TextUtils.isEmpty(name)) {
           name = ".pic";
       }

       switch (type) {
           case JPEG:
               name = name + ".jpg";
               break;
           case PNG:
               name = name + ".png";
               break;
           default:
               break;

       }
       return new File(getTempDirectoryPath(mContext), name);

   }

   private Bitmap getRealCompressedBitmap(String pathName, int reqWidth, int reqHeight) {
       Bitmap bitmap;
       BitmapFactory.Options options = new BitmapFactory.Options();
       options.inJustDecodeBounds = true;
       BitmapFactory.decodeFile(pathName, options);
       int width = options.outWidth / 2;
       int height = options.outHeight / 2;
       int inSampleSize = 1;

       while (width / inSampleSize >= reqWidth && height / inSampleSize >= reqHeight) {
           inSampleSize = inSampleSize * 2;
       }

       options.inSampleSize = inSampleSize;
       options.inJustDecodeBounds = false;
       bitmap = BitmapFactory.decodeFile(pathName, options);
       showBitmapInfos(pathName);
       return bitmap;
   }

链接：https://juejin.im/post/58bc1f11ac502e006b0957b7