Notes

package com.app.ChatLibDemo.mediapicker;

import android.content.Context;
import android.database.Cursor;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.media.ExifInterface;
import android.net.Uri;
import android.provider.MediaStore;
import android.support.annotation.WorkerThread;

import com.app.ChatLibDemo.utils.Log;

import java.io.BufferedOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.UUID;


public class Utility {
private static final String TAG = "Utility";

public static String compressImage(String path) throws IOException {
File file = new File(path);
Bitmap bitmap = BitmapFactory.decodeFile(path);
OutputStream os = new BufferedOutputStream(new FileOutputStream(file));
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, os);
os.close();
return path;
}

public static String getRandomString() {
// return SystemClock.currentThreadTimeMillis()+"";
return UUID.randomUUID().toString();
}

public static void createFolder(String path) {
try {
File dir = new File(path.substring(0, path.lastIndexOf("/")));
Log.e(TAG, "createFolder: " + dir.exists());
if (!dir.exists()) {
dir.mkdirs();
}
} catch (Exception ex) {
android.util.Log.w(TAG, "creating file error: ", ex);
}

}

public static String getRealPathFromURI(Context context, Uri contentUri) {
Cursor cursor = null;
try {
String[] proj = {MediaStore.Images.Media.DATA};
cursor = context.getContentResolver().query(contentUri, proj, null, null, null);
assert cursor != null;
int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
cursor.moveToFirst();
return cursor.getString(column_index);
} finally {
if (cursor != null) {
cursor.close();
}
}
}

@WorkerThread
public static void compressAndRotateIfNeeded(File sourceFile, File destinationFile, int value, int reqWidth, int reqHeight) throws IOException {

String path = sourceFile.getAbsolutePath();

BitmapFactory.Options bounds = new BitmapFactory.Options();
Bitmap bm;
if (reqHeight != 0 && reqWidth != 0) {
bounds.inJustDecodeBounds = true;
bm = BitmapFactory.decodeFile(path, bounds);
bounds.inSampleSize = calculateInSampleSize(bounds, reqWidth, reqHeight);
bounds.inJustDecodeBounds = false;
}
bm = BitmapFactory.decodeFile(path, bounds);

if (bm == null) {
Log.e("compress", "bitmap is null");
return;
}

int rotationAngle = getCameraPhotoOrientation(sourceFile);

Matrix matrix = new Matrix();
matrix.postRotate(rotationAngle, (float) bm.getWidth() / 2, (float) bm.getHeight() / 2);
Bitmap rotatedBitmap = Bitmap.createBitmap(bm, 0, 0, bounds.outWidth, bounds.outHeight,
matrix, true);

FileOutputStream fos = new FileOutputStream(destinationFile.getAbsoluteFile());
rotatedBitmap.compress(Bitmap.CompressFormat.JPEG, value, fos);
fos.flush();
fos.close();
}

private static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
// Raw height and width of image
final int height = options.outHeight;
final int width = options.outWidth;
int inSampleSize = 1;

if (height > reqHeight || width > reqWidth) {

final int halfHeight = height / 2;
final int halfWidth = width / 2;

// Calculate the largest inSampleSize value that is a power of 2 and keeps both
// height and width larger than the requested height and width.
while ((halfHeight / inSampleSize) >= reqHeight
&& (halfWidth / inSampleSize) >= reqWidth) {
inSampleSize *= 2;
}
}

return inSampleSize;
}

@WorkerThread
private static int getCameraPhotoOrientation(File file) throws IOException {
ExifInterface exif = new ExifInterface(
file.getAbsolutePath());
int orientation = exif.getAttributeInt(
ExifInterface.TAG_ORIENTATION,
ExifInterface.ORIENTATION_NORMAL);

int rotate = 0;

switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_270:
rotate = 270;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
rotate = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_90:
rotate = 90;
break;
default:
break;
}

return rotate;
}

}