Android File Permission

Manifest

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

<uses-feature android:glEsVersion="0x00020000" android:required="true" />

起動後

    private static final int REQUEST_EXTERNAL_STORAGE = 787;
    private static String[] PERMISSIONS_STORAGE = {
            Manifest.permission.READ_EXTERNAL_STORAGE,
            Manifest.permission.WRITE_EXTERNAL_STORAGE
    };

   void requestPermission() {
        // activityは、これを実行するアクティビティ
        // REQUEST_WRITE_PERMISSIONは、8bit以下の整数定数
 /* Context context = getBaseContext();
 if (ContextCompat.checkSelfPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE) !=
 PackageManager.PERMISSION_GRANTED) {
 // 以前に許諾して、今後表示しないとしていた場合は、ここにはこない
 String[] permissions = new String[] {
 Manifest.permission.WRITE_EXTERNAL_STORAGE
 };
 ActivityCompat.requestPermissions(this, permissions, REQUEST_WRITE_PERMISSION);
 } else {
 // 許諾されているので、やりたいことをする
 }*/

        int permission = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
        if (permission != PackageManager.PERMISSION_GRANTED) {
            // We don't have permission so prompt the user
            ActivityCompat.requestPermissions(
                    this,
                    PERMISSIONS_STORAGE,
                    REQUEST_EXTERNAL_STORAGE
            );
        }
    }