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Lesson 3: Can't get scrapbook to work.

Open Discussion
jtop65
2007-09-07
2013-04-09

  • jtop65

    jtop65 - 2007-09-07

    Mark,

    I've completed all of the lessons, learned alot, etc. 

    However, i have never been able to get the scrapbook working under Eclipse or MyEclipse.

    Inspecting the result of Evaluating "2+2" always results in:

    2+2An exception occurred during evaluation:  java.lang.ClassNotFoundException

    My lesson code compiles and runs just fine.  JUnit testing too.

     

    • Mark Dexter

      Mark Dexter - 2007-09-07

      Hi. That's very strange. What operating system and Eclipse version are you running? Also, what version of the Jave Runtime Engine are you running? Mark

       

    • jtop65

      jtop65 - 2007-09-08

      I am running XP Pro and Eclipse 3.3 and JRE lib jrel 1.6.0_02  

      My problem appears to be networking related.   I am running Windows networking.  I have three XP home edition machines on the network plus one Linux based Network attached storage unit running windows networking.

      If i create a new/empty C:\Eclipse Workspace folder, load eclipse 3.3, point workspace to C:\Eclipse Workspace, add java project "test" accept defaults, add Scrapbook page "tt" accept defaults and then:

      2+2 Evaluation/display will work.

      If i create a Eclipse Workspace folder on a networked drive (either on a Windows XP home edition machine or on the NAS unit) and switch the Eclipse Workspace to the folder via a network path, i.e.
      "\\XPmachine\Shared Folders\Eclipse Workspace", create the same test java project and tt scrapbook page as done above, then the "2+2" test fails with the java runtime error.

      If on my local XP Pro system I map a Drive letter to the same network path, i.e. Q drive = \\XPmachine\Shared Folders\Eclipse Workspace and then switch the Eclipse Workspace to the "Q:" drive, then the same scrapbook will evaluate/display 2+2 result of 4 just fine.

       

      • Mark Dexter

        Mark Dexter - 2007-09-08

        Hi. That's some pretty good detective work! I just tried it on my home network and got similar, but slightly different, results. On mine, I could not successfully create a new project on a workspace on a non-mapped network location. So I couldn't test the scrapbook. When I mapped the same network location to a local drive, everything worked fine.

        I just did a search on the Eclipse website for "workspace network" in the Eclipse newcomers newsgroup, and evidently Eclipse does not support storing workspaces on network drives in general.

        I'm glad you were able to solve the mystery. Mark

         

    • Joshua Wojnas

      Joshua Wojnas - 2007-12-12

      I am using UBUNTU 7.10 and the 2+2 and int a; a=a*10; a in scrapbook did not work for me eather. I was thinking I did not setup java runtime environment because it was still using gcj or whatever the default one was. I am in window$ now so I can't pull it up to reference it. But I am glad someone else had this problem and now I can move further in eclipse and java and these wonderful tutorials.

       

    • Rick_

      Rick_ - 2008-07-06

      I hope this resolves your issue or others that follow. The problem you are having is only on the XP Home machine. The feature to run a JVM was disabled in the Home edition. This was to cause developers to upgrade to XP Pro while leaving  the home alone to run games that use their own JVM and Office Products. This was well documented on the web when XP was new. There are work-arounds, but the best solution is/was to upgrade to XP. Run Eclipse on the Pro box and you will be fine.

      HTH,

      Rick_

       

    • Catherine Kruchiniina

      Catherine Kruchiniina - 2008-10-28

      Hello, Mark
      I have the same problem with my ScrapBook:
      2+2
      int a; a=a*10; a
      System.out.println("Hello World!");

      Person p = new Person();
      p

      always return the same result when i try to inspect or execute them…
      I use Mac OS X version 10.4.1 and Eclipse Platform Version: 3.4.1 and, honestly, I don't know where to look for a version of JRE I'm running.
      or it must be downloaded  separately?

      Thanks for your wonderfull lessons =)

      Best wishes, Kate

       

    • Catherine Kruchiniina

      Catherine Kruchiniina - 2008-10-28

      p.s. the result is "An exception occurred during evaluation:  java.lang.ClassNotFoundException"

      like in one of the previous topic…

       

      • Mark Dexter

        Mark Dexter - 2008-10-28

        Hi Kate. You can see what JRE (Java Runtime Engine) is being used from inside Eclipse. Go to Window->Preferences->Java->Installed JREs. Also, there is information on troubleshooting an Eclipse installation on the Eclipse website. Here is a link that might help: http://wiki.eclipse.org/FAQ_Where_do_I_get_and_install_Eclipse%3F

        This one might help as well: http://wiki.eclipse.org/FAQ_How_do_I_run_Eclipse%3F

        Good luck. Mark

         

    • Catherine Kruchiniina

      Catherine Kruchiniina - 2008-10-28

      Hi, Mark. thanks for help =) (also we could find JRE version in the package window as i understand a bit later)
      Now I know that I'm running JVM 1.5.0(Mac OS X Default) but it's still unclear what I should do with my ScrapBook's problem…)

      Thanks for answer, Kate

       

    • Mark Dexter

      Mark Dexter - 2008-10-28

      Hi. Well I don't know the answer. I assume you are not trying to run a workspace on a networked drive?

      Unfortunately, I don't have much experience with Mac OS X and don't have one for testing. You could try posting a question on the Eclipse Newcomers group. Here is the link: http://www.eclipse.org/newsportal/thread.php?group=eclipse.newcomer

      Good luck. You can of course continue with the tutorials without the scrapbook, but it should work for you. Mark

       

    • Catherine Kruchiniina

      Catherine Kruchiniina - 2008-10-28

      Ok, thanks one more time )
      Kate

       

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