Why can't I write to the Raspbian Jessie filesystem?

bjuntti

So, I'm trying to write a file on a Raspbian Jessie filesystem that my Raspberry Pi 2 Model B is

using and I'm not having any luck.  Here's a code snippet:

FilePersistentStore fileStore = new FilePersistentStore("/rootfs/var/tmp/baro-data.txt", true, INFO);

public FilePersistentStore(String fileName, boolean verbose, int messageLevel)

      throws IOException {

    this.verbose = verbose;

    this.messageLevel = messageLevel;

   

   

      /* Open the file for writing */

      String connectorName = "file://" + fileName;

      printMessage("constructor opening file: [" + connectorName + "]", INFO);

      connection = (FileConnection)Connector.open(connectorName,

          Connector.READ_WRITE);

     

      System.out.println("[FilePersistentStore] Line 51");

      /* If the file does not exist yet, create it */

      if (!connection.exists()) {

        printMessage("File does not exist, creating", INFO);

        connection.create();

      }

      System.out.println("[FilePersistentStore] Line 57");

      fileWriter = new PrintStream(connection.openOutputStream(), true);

      printMessage("Got IO streams", INFO);

  }

Note that I'm writing (or TRYING to write) to the file name "/rootfs/var/tmp/baro-data.txt" (one of

the stipulations made during the JavaME MOOC class was that YOU MUST DIRECT THE WRITE TO ROOTFS.)

This code HANGS on the Pi 2 but when I ran it on my older RPi Model B, it ran fine.  Turns out there

IS a filesystem called 'rootfs' on the older OS for the older Pi but no 'rootfs' in Jessie. 

Anybody have any ideas?

Thanks,

Bruce

Alexander.Belokrylov-Oracle

Bruce,

Thank you for your feedback.

Unfortunately Java ME Embedded 8.2 which I supposed you use, have not beet tested with RPi2.

However today we have just released Java ME Embedded 8.3, please check if it works for you.

Oracle Java ME Embedded Overview

bjuntti

Hi Alexander,

Thanks for the reply and sorry for the delay.  I tried 8.3 but was having problems compiling now.  So I went back to 8.2 for now.   I have other parts of my project to work on and the need to write to the filesystem isn't that pressing right now.  I'll try again at some point.

Bruce