Setup a FileProvider for Android with paths for root, external storage, and internal app files

AndroidManifest.xml

<manifest package="com.jaredrummler.android.common"
          xmlns:android="http://schemas.android.com/apk/res/android">

  <application>
    <provider
        android:name="com.jaredrummler.android.files.FileProvider"
        android:authorities="${applicationId}.fileprovider"
        android:exported="false"
        android:grantUriPermissions="true">
      <meta-data
          android:name="android.support.FILE_PROVIDER_PATHS"
          android:resource="@xml/root_paths"/>
    </provider>
  </application>

</manifest>

FileProvider.java

package com.jaredrummler.android.files;

import android.database.Cursor;
import android.database.MatrixCursor;
import android.net.Uri;
import android.provider.MediaStore;
import java.util.Arrays;

/**
 * A {@link FileProvider} that supports apps which rely on {@link MediaStore.MediaColumns#DATA}
 *
 * @see <a href="http://stackoverflow.com/a/25020642">http://stackoverflow.com/a/25020642</a>
 */
public class FileProvider extends android.support.v4.content.FileProvider {

  public static final String AUTHORITY = App.getContext().getPackageName() + ".fileprovider";

  @Override
  public Cursor query(Uri uri, String[] projection, String selection, String[] selectionArgs, String sortOrder) {
    final Cursor source = super.query(uri, projection, selection, selectionArgs, sortOrder);

    /*
        It's not necessary to overwrite
            public Cursor query(final Uri uri, final String[] projection, final String selection, final String[]
                selectionArgs, final String sortOrder, final CancellationSignal cancellationSignal);
        cause it calls this method.
        == What's happening here? ==
        Some apps rely on the MediaStore.MediaColumns.DATA column in the cursor. To prevent them
        from crashing, we have to copy the initial cursor and add the MediaStore.MediaColumns.DATA
        column. The values of this column will always be null, but we assume that they are able
        to handle that case.
    */

    if (source == null) {
      android.util.Log.w("TAG", "Not able to apply workaround, super.query(...) returned null");
      return null;
    }

    String[] columnNames = source.getColumnNames();
    String[] newColumnNames = columnNamesWithData(columnNames);

    MatrixCursor cursor = new MatrixCursor(newColumnNames, source.getCount());
    if (cursor.moveToFirst()) {
      do {
        MatrixCursor.RowBuilder row = cursor.newRow();
        for (int i = 0; i < columnNames.length; i++) {
          row.add(source.getString(i));
        }
      } while (cursor.moveToNext());
    }
    source.close();

    return cursor;
  }

  private String[] columnNamesWithData(String[] columnNames) {
    for (String columnName : columnNames) {
      if (MediaStore.MediaColumns.DATA.equals(columnName)) {
        return columnNames;
      }
    }

    String[] newColumnNames = Arrays.copyOf(columnNames, columnNames.length + 1);
    newColumnNames[columnNames.length] = MediaStore.MediaColumns.DATA;
    return newColumnNames;
  }

}

root_paths.xml

<?xml version="1.0" encoding="utf-8"?>
<paths>
  <root-path
      name="root"
      path="."/>
  <files-path
      name="files"
      path="."/>
  <cache-path
      name="cache"
      path="."/>
  <external-path
      name="external"
      path="."/>
  <external-files-path
      name="external-files"
      path="."/>
  <external-cache-path
      name="external-cache"
      path="."/>
</paths>