diff --git a/app/src/main/java/io/legado/app/ui/filechooser/utils/ConvertUtils.java b/app/src/main/java/io/legado/app/ui/filechooser/utils/ConvertUtils.java
deleted file mode 100644
index e4440143f..000000000
--- a/app/src/main/java/io/legado/app/ui/filechooser/utils/ConvertUtils.java
+++ /dev/null
@@ -1,617 +0,0 @@
-package io.legado.app.ui.filechooser.utils;
-
-import android.annotation.TargetApi;
-import android.content.ContentUris;
-import android.content.Context;
-import android.content.res.ColorStateList;
-import android.content.res.Resources;
-import android.database.Cursor;
-import android.graphics.Bitmap;
-import android.graphics.BitmapFactory;
-import android.graphics.Canvas;
-import android.graphics.Color;
-import android.graphics.drawable.BitmapDrawable;
-import android.graphics.drawable.ColorDrawable;
-import android.graphics.drawable.Drawable;
-import android.graphics.drawable.NinePatchDrawable;
-import android.net.Uri;
-import android.os.Build;
-import android.os.Environment;
-import android.provider.DocumentsContract;
-import android.provider.MediaStore;
-import android.text.TextUtils;
-import android.view.View;
-import android.widget.ListView;
-import android.widget.ScrollView;
-
-import androidx.annotation.ColorInt;
-import androidx.annotation.FloatRange;
-
-import java.io.BufferedReader;
-import java.io.ByteArrayOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.io.InputStreamReader;
-import java.io.UnsupportedEncodingException;
-import java.nio.ByteBuffer;
-import java.text.DecimalFormat;
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * 数据类型转换、单位转换
- *
- * @author 李玉江[QQ:1023694760]
- * @since 2014-4-18
- */
-public class ConvertUtils {
-    public static final long GB = 1073741824;
-    public static final long MB = 1048576;
-    public static final long KB = 1024;
-
-    public static int toInt(Object obj) {
-        try {
-            return Integer.parseInt(obj.toString());
-        } catch (NumberFormatException e) {
-            return -1;
-        }
-    }
-
-    public static int toInt(byte[] bytes) {
-        int result = 0;
-        byte abyte;
-        for (int i = 0; i < bytes.length; i++) {
-            abyte = bytes[i];
-            result += (abyte & 0xFF) << (8 * i);
-        }
-        return result;
-    }
-
-    public static int toShort(byte first, byte second) {
-        return (first << 8) + (second & 0xFF);
-    }
-
-    public static long toLong(Object obj) {
-        try {
-            return Long.parseLong(obj.toString());
-        } catch (NumberFormatException e) {
-            return -1L;
-        }
-    }
-
-    public static float toFloat(Object obj) {
-        try {
-            return Float.parseFloat(obj.toString());
-        } catch (NumberFormatException e) {
-            return -1f;
-        }
-    }
-
-    /**
-     * int占4字节
-     *
-     * @param i the
-     * @return byte [ ]
-     */
-    public static byte[] toByteArray(int i) {
-        // byte[] bytes = new byte[4];
-        // bytes[0] = (byte) (0xff & i);
-        // bytes[1] = (byte) ((0xff00 & i) >> 8);
-        // bytes[2] = (byte) ((0xff0000 & i) >> 16);
-        // bytes[3] = (byte) ((0xff000000 & i) >> 24);
-        // return bytes;
-        return ByteBuffer.allocate(4).putInt(i).array();
-    }
-
-    public static byte[] toByteArray(String hexData, boolean isHex) {
-        if (hexData == null || hexData.equals("")) {
-            return null;
-        }
-        if (!isHex) {
-            return hexData.getBytes();
-        }
-        hexData = hexData.replaceAll("\\s+", "");
-        String hexDigits = "0123456789ABCDEF";
-        ByteArrayOutputStream baos = new ByteArrayOutputStream(
-                hexData.length() / 2);
-        // 将每2位16进制整数组装成一个字节
-        for (int i = 0; i < hexData.length(); i += 2) {
-            baos.write((hexDigits.indexOf(hexData.charAt(i)) << 4 | hexDigits
-                    .indexOf(hexData.charAt(i + 1))));
-        }
-        byte[] bytes = baos.toByteArray();
-        try {
-            baos.close();
-        } catch (IOException e) {
-        }
-        return bytes;
-    }
-
-    public static String toHexString(String str) {
-        if (TextUtils.isEmpty(str))
-            return "";
-        StringBuilder builder = new StringBuilder();
-        byte[] bytes = str.getBytes();
-        for (byte aByte : bytes) {
-            builder.append(Integer.toHexString(0xFF & aByte));
-            builder.append(" ");
-        }
-        return builder.toString();
-    }
-
-    /**
-     * To hex string string.
-     *
-     * @param bytes the bytes
-     * @return the string
-     */
-    public static String toHexString(byte... bytes) {
-        char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6',
-                '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
-        // 参见：http://www.oschina.net/code/snippet_116768_9019
-        char[] buffer = new char[bytes.length * 2];
-        for (int i = 0, j = 0; i < bytes.length; ++i) {
-            int u = bytes[i] < 0 ? bytes[i] + 256 : bytes[i];//转无符号整型
-            buffer[j++] = DIGITS[u >>> 4];
-            buffer[j++] = DIGITS[u & 0xf];
-        }
-        return new String(buffer);
-    }
-
-    /**
-     * To hex string string.
-     *
-     * @param num the num
-     * @return the string
-     */
-    public static String toHexString(int num) {
-        String hexString = Integer.toHexString(num);
-        return hexString;
-    }
-
-    /**
-     * To binary string string.
-     *
-     * @param bytes the bytes
-     * @return the string
-     */
-    public static String toBinaryString(byte... bytes) {
-        char[] DIGITS = {'0', '1', '2', '3', '4', '5', '6',
-                '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
-        // 参见：http://www.oschina.net/code/snippet_116768_9019
-        char[] buffer = new char[bytes.length * 8];
-        for (int i = 0, j = 0; i < bytes.length; ++i) {
-            int u = bytes[i] < 0 ? bytes[i] + 256 : bytes[i];//转无符号整型
-            buffer[j++] = DIGITS[(u >>> 7) & 0x1];
-            buffer[j++] = DIGITS[(u >>> 6) & 0x1];
-            buffer[j++] = DIGITS[(u >>> 5) & 0x1];
-            buffer[j++] = DIGITS[(u >>> 4) & 0x1];
-            buffer[j++] = DIGITS[(u >>> 3) & 0x1];
-            buffer[j++] = DIGITS[(u >>> 2) & 0x1];
-            buffer[j++] = DIGITS[(u >>> 1) & 0x1];
-            buffer[j++] = DIGITS[u & 0x1];
-        }
-        return new String(buffer);
-    }
-
-    /**
-     * To binary string string.
-     *
-     * @param num the num
-     * @return the string
-     */
-    public static String toBinaryString(int num) {
-        String binaryString = Integer.toBinaryString(num);
-        return binaryString;
-    }
-
-    public static String toSlashString(String str) {
-        String result = "";
-        char[] chars = str.toCharArray();
-        for (char chr : chars) {
-            if (chr == '"' || chr == '\'' || chr == '\\') {
-                result += "\\";//符合“"”“'”“\”这三个符号的前面加一个“\”
-            }
-            result += chr;
-        }
-        return result;
-    }
-
-    public static <T> T[] toArray(List<T> list) {
-        //noinspection unchecked
-        return (T[]) list.toArray();
-    }
-
-    public static <T> List<T> toList(T[] array) {
-        return Arrays.asList(array);
-    }
-
-    public static String toString(Object[] objects) {
-        return Arrays.deepToString(objects);
-    }
-
-    public static String toString(Object[] objects, String tag) {
-        StringBuilder sb = new StringBuilder();
-        for (Object object : objects) {
-            sb.append(object);
-            sb.append(tag);
-        }
-        return sb.toString();
-    }
-
-    public static byte[] toByteArray(InputStream is) {
-        if (is == null) {
-            return null;
-        }
-        try {
-            ByteArrayOutputStream os = new ByteArrayOutputStream();
-            byte[] buff = new byte[100];
-            while (true) {
-                int len = is.read(buff, 0, 100);
-                if (len == -1) {
-                    break;
-                } else {
-                    os.write(buff, 0, len);
-                }
-            }
-            byte[] bytes = os.toByteArray();
-            os.close();
-            is.close();
-            return bytes;
-        } catch (IOException e) {
-        }
-        return null;
-    }
-
-    public static byte[] toByteArray(Bitmap bitmap) {
-        if (bitmap == null) {
-            return null;
-        }
-        ByteArrayOutputStream os = new ByteArrayOutputStream();
-        // 将Bitmap压缩成PNG编码，质量为100%存储，除了PNG还有很多常见格式，如jpeg等。
-        bitmap.compress(Bitmap.CompressFormat.PNG, 100, os);
-        byte[] bytes = os.toByteArray();
-        try {
-            os.close();
-        } catch (IOException e) {
-        }
-        return bytes;
-    }
-
-    public static Bitmap toBitmap(byte[] bytes, int width, int height) {
-        Bitmap bitmap = null;
-        if (bytes.length != 0) {
-            try {
-                BitmapFactory.Options options = new BitmapFactory.Options();
-                // 不进行图片抖动处理
-                options.inDither = false;
-                // 设置让解码器以最佳方式解码
-                options.inPreferredConfig = null;
-                if (width > 0 && height > 0) {
-                    options.outWidth = width;
-                    options.outHeight = height;
-                }
-                bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.length, options);
-                bitmap.setDensity(96);// 96 dpi
-            } catch (Exception e) {
-            }
-        }
-        return bitmap;
-    }
-
-    public static Bitmap toBitmap(byte[] bytes) {
-        return toBitmap(bytes, -1, -1);
-    }
-
-    /**
-     * 将Drawable转换为Bitmap
-     * 参考：http://kylines.iteye.com/blog/1660184
-     */
-    public static Bitmap toBitmap(Drawable drawable) {
-        if (drawable instanceof BitmapDrawable) {
-            return ((BitmapDrawable) drawable).getBitmap();
-        } else if (drawable instanceof ColorDrawable) {
-            //color
-            Bitmap bitmap = Bitmap.createBitmap(32, 32, Bitmap.Config.ARGB_8888);
-            Canvas canvas = new Canvas(bitmap);
-            canvas.drawColor(((ColorDrawable) drawable).getColor());
-            return bitmap;
-        } else if (drawable instanceof NinePatchDrawable) {
-            //.9.png
-            Bitmap bitmap = Bitmap.createBitmap(drawable.getIntrinsicWidth(),
-                    drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
-            Canvas canvas = new Canvas(bitmap);
-            drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
-            drawable.draw(canvas);
-            return bitmap;
-        }
-        return null;
-    }
-
-    /**
-     * 从第三方文件选择器获取路径。
-     * 参见：http://blog.csdn.net/zbjdsbj/article/details/42387551
-     */
-    @TargetApi(Build.VERSION_CODES.KITKAT)
-    public static String toPath(Context context, Uri uri) {
-        if (uri == null) {
-            return "";
-        }
-        String path = uri.getPath();
-        String scheme = uri.getScheme();
-        String authority = uri.getAuthority();
-        //是否是4.4及以上版本
-        boolean isKitKat = Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT;
-        // DocumentProvider
-        if (isKitKat && DocumentsContract.isDocumentUri(context, uri)) {
-            String docId = DocumentsContract.getDocumentId(uri);
-            String[] split = docId.split(":");
-            String type = split[0];
-            Uri contentUri = null;
-            switch (authority) {
-                // ExternalStorageProvider
-                case "com.android.externalstorage.documents":
-                    if ("primary".equalsIgnoreCase(type)) {
-                        return Environment.getExternalStorageDirectory() + "/" + split[1];
-                    }
-                    break;
-                // DownloadsProvider
-                case "com.android.providers.downloads.documents":
-                    contentUri = ContentUris.withAppendedId(
-                            Uri.parse("content://downloads/public_downloads"), Long.valueOf(docId));
-                    return _queryPathFromMediaStore(context, contentUri, null, null);
-                // MediaProvider
-                case "com.android.providers.media.documents":
-                    if ("image".equals(type)) {
-                        contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
-                    } else if ("video".equals(type)) {
-                        contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
-                    } else if ("audio".equals(type)) {
-                        contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
-                    }
-                    String selection = "_id=?";
-                    String[] selectionArgs = new String[]{split[1]};
-                    return _queryPathFromMediaStore(context, contentUri, selection, selectionArgs);
-            }
-        }
-        // MediaStore (and general)
-        else {
-            if ("content".equalsIgnoreCase(scheme)) {
-                // Return the remote address
-                if (authority.equals("com.google.android.apps.photos.content")) {
-                    return uri.getLastPathSegment();
-                }
-                return _queryPathFromMediaStore(context, uri, null, null);
-            }
-            // File
-            else if ("file".equalsIgnoreCase(scheme)) {
-                return uri.getPath();
-            }
-        }
-        return path;
-    }
-
-    private static String _queryPathFromMediaStore(Context context, Uri uri, String selection, String[] selectionArgs) {
-        String filePath = null;
-        try {
-            String[] projection = {MediaStore.Images.Media.DATA};
-            Cursor cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs, null);
-            if (cursor != null) {
-                int column_index = cursor.getColumnIndexOrThrow(MediaStore.Images.Media.DATA);
-                cursor.moveToFirst();
-                filePath = cursor.getString(column_index);
-                cursor.close();
-            }
-        } catch (IllegalArgumentException e) {
-        }
-        return filePath;
-    }
-
-    /**
-     * 把view转化为bitmap（截图）
-     * 参见：http://www.cnblogs.com/lee0oo0/p/3355468.html
-     */
-    public static Bitmap toBitmap(View view) {
-        int width = view.getWidth();
-        int height = view.getHeight();
-        if (view instanceof ListView) {
-            height = 0;
-            // 获取listView实际高度
-            ListView listView = (ListView) view;
-            for (int i = 0; i < listView.getChildCount(); i++) {
-                height += listView.getChildAt(i).getHeight();
-            }
-        } else if (view instanceof ScrollView) {
-            height = 0;
-            // 获取scrollView实际高度
-            ScrollView scrollView = (ScrollView) view;
-            for (int i = 0; i < scrollView.getChildCount(); i++) {
-                height += scrollView.getChildAt(i).getHeight();
-            }
-        }
-        view.setDrawingCacheEnabled(true);
-        view.clearFocus();
-        view.setPressed(false);
-        boolean willNotCache = view.willNotCacheDrawing();
-        view.setWillNotCacheDrawing(false);
-        // Reset the drawing cache background color to fully transparent for the duration of this operation
-        int color = view.getDrawingCacheBackgroundColor();
-        view.setDrawingCacheBackgroundColor(Color.WHITE);//截图去黑色背景(透明像素)
-        if (color != Color.WHITE) {
-            view.destroyDrawingCache();
-        }
-        view.buildDrawingCache();
-        Bitmap cacheBitmap = view.getDrawingCache();
-        if (cacheBitmap == null) {
-            return null;
-        }
-        Bitmap bitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
-        Canvas canvas = new Canvas(bitmap);
-        canvas.drawBitmap(cacheBitmap, 0, 0, null);
-        canvas.save();
-        canvas.restore();
-        if (!bitmap.isRecycled()) {
-            bitmap.recycle();
-        }
-        // Restore the view
-        view.destroyDrawingCache();
-        view.setWillNotCacheDrawing(willNotCache);
-        view.setDrawingCacheBackgroundColor(color);
-        return bitmap;
-    }
-
-    public static Drawable toDrawable(Bitmap bitmap) {
-        return bitmap == null ? null : new BitmapDrawable(Resources.getSystem(), bitmap);
-    }
-
-    public static byte[] toByteArray(Drawable drawable) {
-        return toByteArray(toBitmap(drawable));
-    }
-
-    public static Drawable toDrawable(byte[] bytes) {
-        return toDrawable(toBitmap(bytes));
-    }
-
-    /**
-     * dp转换为px
-     */
-    public static int toPx(Context context, float dpValue) {
-        final float scale = context.getResources().getDisplayMetrics().density;
-        int pxValue = (int) (dpValue * scale + 0.5f);
-        return pxValue;
-    }
-
-    /**
-     * px转换为dp
-     */
-    public static int toDp(Context context, float pxValue) {
-        final float scale = context.getResources().getDisplayMetrics().density;
-        int dpValue = (int) (pxValue / scale + 0.5f);
-        return dpValue;
-    }
-
-    /**
-     * px转换为sp
-     */
-    public static int toSp(Context context, float pxValue) {
-        final float fontScale = context.getResources().getDisplayMetrics().scaledDensity;
-        int spValue = (int) (pxValue / fontScale + 0.5f);
-        return spValue;
-    }
-
-    public static String toGbk(String str) {
-        try {
-            return new String(str.getBytes("utf-8"), "gbk");
-        } catch (UnsupportedEncodingException e) {
-            return str;
-        }
-    }
-
-    public static String toFileSizeString(long fileSize) {
-        DecimalFormat df = new DecimalFormat("0.00");
-        String fileSizeString;
-        if (fileSize < KB) {
-            fileSizeString = fileSize + "B";
-        } else if (fileSize < MB) {
-            fileSizeString = df.format((double) fileSize / KB) + "K";
-        } else if (fileSize < GB) {
-            fileSizeString = df.format((double) fileSize / MB) + "M";
-        } else {
-            fileSizeString = df.format((double) fileSize / GB) + "G";
-        }
-        return fileSizeString;
-    }
-
-    public static String toString(InputStream is, String charset) {
-        StringBuilder sb = new StringBuilder();
-        try {
-            BufferedReader reader = new BufferedReader(new InputStreamReader(is, charset));
-            while (true) {
-                String line = reader.readLine();
-                if (line == null) {
-                    break;
-                } else {
-                    sb.append(line).append("\n");
-                }
-            }
-            reader.close();
-            is.close();
-        } catch (IOException e) {
-        }
-        return sb.toString();
-    }
-
-    public static String toString(InputStream is) {
-        return toString(is, "utf-8");
-    }
-
-    public static int toDarkenColor(@ColorInt int color) {
-        return toDarkenColor(color, 0.8f);
-    }
-
-    public static int toDarkenColor(@ColorInt int color, @FloatRange(from = 0f, to = 1f) float value) {
-        float[] hsv = new float[3];
-        Color.colorToHSV(color, hsv);
-        hsv[2] *= value;//HSV指Hue、Saturation、Value，即色调、饱和度和亮度，此处表示修改亮度
-        return Color.HSVToColor(hsv);
-    }
-
-    /**
-     * 转换为6位十六进制颜色代码，不含“#”
-     */
-    public static String toColorString(@ColorInt int color) {
-        return toColorString(color, false);
-    }
-
-    /**
-     * 转换为6位十六进制颜色代码，不含“#”
-     */
-    public static String toColorString(@ColorInt int color, boolean includeAlpha) {
-        String alpha = Integer.toHexString(Color.alpha(color));
-        String red = Integer.toHexString(Color.red(color));
-        String green = Integer.toHexString(Color.green(color));
-        String blue = Integer.toHexString(Color.blue(color));
-        if (alpha.length() == 1) {
-            alpha = "0" + alpha;
-        }
-        if (red.length() == 1) {
-            red = "0" + red;
-        }
-        if (green.length() == 1) {
-            green = "0" + green;
-        }
-        if (blue.length() == 1) {
-            blue = "0" + blue;
-        }
-        String colorString;
-        if (includeAlpha) {
-            colorString = alpha + red + green + blue;
-        } else {
-            colorString = red + green + blue;
-        }
-        return colorString;
-    }
-
-    /**
-     * 对TextView、Button等设置不同状态时其文字颜色。
-     * 参见：http://blog.csdn.net/sodino/article/details/6797821
-     * Modified by liyujiang at 2015.08.13
-     */
-    public static ColorStateList toColorStateList(@ColorInt int normalColor, @ColorInt int pressedColor,
-                                                  @ColorInt int focusedColor, @ColorInt int unableColor) {
-        int[] colors = new int[]{pressedColor, focusedColor, normalColor, focusedColor, unableColor, normalColor};
-        int[][] states = new int[6][];
-        states[0] = new int[]{android.R.attr.state_pressed, android.R.attr.state_enabled};
-        states[1] = new int[]{android.R.attr.state_enabled, android.R.attr.state_focused};
-        states[2] = new int[]{android.R.attr.state_enabled};
-        states[3] = new int[]{android.R.attr.state_focused};
-        states[4] = new int[]{android.R.attr.state_window_focused};
-        states[5] = new int[]{};
-        return new ColorStateList(states, colors);
-    }
-
-    public static ColorStateList toColorStateList(@ColorInt int normalColor, @ColorInt int pressedColor) {
-        return toColorStateList(normalColor, pressedColor, pressedColor, normalColor);
-    }
-
-}
diff --git a/app/src/main/java/io/legado/app/ui/filechooser/utils/ConvertUtils.kt b/app/src/main/java/io/legado/app/ui/filechooser/utils/ConvertUtils.kt
new file mode 100644
index 000000000..0e0ae30a8
--- /dev/null
+++ b/app/src/main/java/io/legado/app/ui/filechooser/utils/ConvertUtils.kt
@@ -0,0 +1,131 @@
+package io.legado.app.ui.filechooser.utils
+
+import android.content.res.Resources
+import android.graphics.Bitmap
+import android.graphics.BitmapFactory
+import android.graphics.drawable.BitmapDrawable
+import android.graphics.drawable.Drawable
+import okhttp3.internal.and
+import java.io.BufferedReader
+import java.io.IOException
+import java.io.InputStream
+import java.io.InputStreamReader
+import java.text.DecimalFormat
+import java.util.*
+
+/**
+ * 数据类型转换、单位转换
+ *
+ * @author 李玉江[QQ:1023694760]
+ * @since 2014-4-18
+ */
+object ConvertUtils {
+    const val GB: Long = 1073741824
+    const val MB: Long = 1048576
+    const val KB: Long = 1024
+
+    fun toInt(obj: Any): Int {
+        return try {
+            Integer.parseInt(obj.toString())
+        } catch (e: NumberFormatException) {
+            -1
+        }
+
+    }
+
+    fun toInt(bytes: ByteArray): Int {
+        var result = 0
+        var abyte: Byte
+        for (i in bytes.indices) {
+            abyte = bytes[i]
+            result += abyte and 0xFF shl 8 * i
+        }
+        return result
+    }
+
+    fun toFloat(obj: Any): Float {
+        return try {
+            java.lang.Float.parseFloat(obj.toString())
+        } catch (e: NumberFormatException) {
+            -1f
+        }
+    }
+
+    fun toString(objects: Array<Any>): String {
+        return Arrays.deepToString(objects)
+    }
+
+    fun toString(objects: Array<Any>, tag: String): String {
+        val sb = StringBuilder()
+        for (`object` in objects) {
+            sb.append(`object`)
+            sb.append(tag)
+        }
+        return sb.toString()
+    }
+
+    @JvmOverloads
+    fun toBitmap(bytes: ByteArray, width: Int = -1, height: Int = -1): Bitmap? {
+        var bitmap: Bitmap? = null
+        if (bytes.isNotEmpty()) {
+            try {
+                val options = BitmapFactory.Options()
+                // 不进行图片抖动处理
+                options.inDither = false
+                // 设置让解码器以最佳方式解码
+                options.inPreferredConfig = null
+                if (width > 0 && height > 0) {
+                    options.outWidth = width
+                    options.outHeight = height
+                }
+                bitmap = BitmapFactory.decodeByteArray(bytes, 0, bytes.size, options)
+                bitmap!!.density = 96// 96 dpi
+            } catch (e: Exception) {
+            }
+
+        }
+        return bitmap
+    }
+
+    fun toDrawable(bitmap: Bitmap?): Drawable? {
+        return if (bitmap == null) null else BitmapDrawable(Resources.getSystem(), bitmap)
+    }
+
+    fun toDrawable(bytes: ByteArray): Drawable? {
+        return toDrawable(toBitmap(bytes))
+    }
+
+    fun toFileSizeString(fileSize: Long): String {
+        val df = DecimalFormat("0.00")
+        val fileSizeString: String
+        fileSizeString = when {
+            fileSize < KB -> fileSize.toString() + "B"
+            fileSize < MB -> df.format(fileSize.toDouble() / KB) + "K"
+            fileSize < GB -> df.format(fileSize.toDouble() / MB) + "M"
+            else -> df.format(fileSize.toDouble() / GB) + "G"
+        }
+        return fileSizeString
+    }
+
+    @JvmOverloads
+    fun toString(`is`: InputStream, charset: String = "utf-8"): String {
+        val sb = StringBuilder()
+        try {
+            val reader = BufferedReader(InputStreamReader(`is`, charset))
+            while (true) {
+                val line = reader.readLine()
+                if (line == null) {
+                    break
+                } else {
+                    sb.append(line).append("\n")
+                }
+            }
+            reader.close()
+            `is`.close()
+        } catch (e: IOException) {
+        }
+
+        return sb.toString()
+    }
+
+}
\ No newline at end of file