Tuesday, June 16, 2009

Eclipse build errors - java.lang.object cannot be resolved

Keywords:
eclipse 3.4.0 ganymede The type java.lang.object "cannot be resolved" "Cannot find the class file" "refers to the missing type"

Problem:
Opened eclipse, it needed to do a full workspace build (probably because ant scripts have updated class files and it needs to refresh). Random classes in the project now no longer compile. Examples of the errors being reported:



DescriptionResourcePathLocationType
The type java.lang.Object cannot be resolved. It is indirectly referenced from required .class filesMyClass.javaMyProject/src/com/exampleline 1Java Problem
The project was not built since its build path is incomplete. Cannot find the class file for java.lang.Object. Fix the build path then try building this projectMyProjectUnknownJava Problem
The method myMethod(SomeClass) from the type MyOtherClass refers to the missing type (insert java type here: InputStream|File|Vector|IOException|etc)MyOtherClass.javaMyProject/src/com/exampleline 123Java Problem


Solution:
It sounds like this has been a known issue (Bug 67414)that was resolved in 3.0 ... someone has commented that it's occurring for them in 3.4 as well.

In the mean time, the work around is to remove the JRE System Library from the project and then add it back again.
Here are the steps:
  1. Go to properties of project with the build error (right click > Properties)
  2. View the "Libraries" tab in the "Build Path" section
  3. Find the "JRE System Library" in the list (if this is missing then this error message is not an eclipse bug but a mis-configured project)
  4. Remove the "JRE System Library"
  5. Hit "Add Library ...", Select "JRE System Library" and add the appropriate JRE for the project (eg. 'Workspace default JRE')
  6. Hit "Finish" in the library selection and "OK" in the project properties and then wait for the re-build of the project
  7. Hopefully the error will be resolved ...
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42 comments:

  1. AnonymousJuly 16, 2009 9:47 am

    Thanks this solution worked!

    I had this exact problem in a new install of Eclipse 3.5 (Galileo).

    I followed the steps above and the problem went away.

    This is what I think caused the problem in the first place: I installed Eclipse and Subclipse, checked out my project, and then set a new default JDK. I think the JRE System Library didn't pick up the new default JDK... maybe I should have set the new default JDK *before* checking out the project.

    Anyway, all fixed, thanks!

    ReplyDelete
  2. AnonymousOctober 07, 2009 8:39 pm

    The error may occur without changing the JDK.

    I saw this problem when:
    - opening Eclipse
    - updating my local CVS repository

    Basically, it occurs when a partial build is triggered but it is not systematic.

    I managed to solve the problem by:
    - changing the position of the JRE in the classpath (it is not necessary to remove it and add it again)
    - changing the global JDK in order to trigger a clean rebuild. Any JDK is good enough. It has just to be different from the former one.

    I have many projects in my workspace so it can be painful to change the classpaths one by one ;)

    J. Le Cren

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  3. AnonymousOctober 08, 2009 5:29 am

    Great, this solution worked, had been a trouble for few days.

    ReplyDelete
  4. Matt HugginsDecember 24, 2009 4:58 pm

    Thanks a ton, this fixed up a problem I was having with all day!

    ReplyDelete
  5. AnonymousFebruary 05, 2010 3:15 am

    Thank you so much.....
    The solution is working....in my SAP Netweaver Developer Studio as well....

    ReplyDelete
  6. Kill Dash NineApril 29, 2010 7:26 pm

    Thanks, it worked!

    ReplyDelete
  7. AnonymousNovember 11, 2010 6:20 am

    the solution worked great thank you so much

    ReplyDelete
  8. AnonymousJanuary 07, 2011 6:31 am

    Thanks a lot for ur help. It really works.

    ReplyDelete
  9. UnknownMarch 08, 2011 6:08 pm

    WOW!!!! that worked like magic to me. thank u thank u thank u

    ReplyDelete
  10. DasonApril 25, 2011 3:37 pm

    I got 1 JRE1.6 running fine all the time but suddenly 1 day it has this same error. So, I tried this method and it didn't work. (but i believe it is correct working procedure)

    So, I use my old JDK1.4 to run the program and it continue to works again. I believe it is the same error just that the JRE/JDK may corrupted. Download again and reinstall the JRE/JDK may helps.

    ReplyDelete
  11. AnonymousJune 29, 2011 4:15 am

    thanks buddy, ur suggestion worked for me.

    ReplyDelete
  12. ShivramJuly 02, 2011 12:19 am

    yes, it worked.

    ReplyDelete
  13. AnonymousJuly 23, 2011 1:54 am

    Thanks this worked! The problem I was facing was the same but the reason was that I moved the project to another workspace manually and then opened eclipse. After adding the JRE library, works again.

    ReplyDelete
  14. limonJuly 25, 2011 2:03 pm

    Thank you very much. I just fixed the problem.

    ReplyDelete
  15. AnonymousDecember 08, 2011 9:28 pm

    Thanks alot for the guidance. The solution indeed work. I was struggling with it for last one day. Proved to be a great help.

    ReplyDelete
  16. AnonymousJanuary 14, 2012 4:13 am

    Thanks solution works like a Charm ............

    ReplyDelete
  17. AnonymousJanuary 31, 2012 2:51 am

    Excellent, thanks!

    ReplyDelete
  18. AnonymousFebruary 22, 2012 7:00 am

    Thanks a lot

    ReplyDelete
  19. Sertaç DEMİRMarch 02, 2012 8:37 pm

    Thank you it realy works for me :)

    ReplyDelete
  20. AnonymousMarch 22, 2012 9:06 pm

    I just had the same problem in Eclipse Indigo. But the solution works. Great!

    ReplyDelete
  21. AnonymousMarch 28, 2012 8:30 pm

    Thanks this worked for me too

    ReplyDelete
  22. AnonymousMarch 28, 2012 8:31 pm

    Thanks this solution worked

    ReplyDelete
  23. AnonymousApril 03, 2012 8:59 pm

    Thank you very much. Just fixed the problem.

    ReplyDelete
  24. AnonymousMay 04, 2012 7:31 am

    very helpful, thx!

    ReplyDelete
  25. AnonymousMay 15, 2012 9:56 pm

    Eclipse IDE for Java Developers
    Version: Indigo Service Release 1
    Build id: 20110916-0149

    Reloaded project from disk, no changes made since last working online. TFS was unavailable, received a warning that the project is working offline. One class in the project failed to build with this error.

    Libraries tab showed "Android Dependencies" and "Unable to get system library for project". Removed last entry, then added "JRE System Library" and "Android Classpath Container" to get it to work.

    ReplyDelete
  26. AnonymousMay 27, 2012 7:05 pm

    Thank you!

    ReplyDelete
  27. UnknownMay 30, 2012 2:02 pm

    Thank you. I am hoping to resolve some long pending issue on my office laptop tomorrow.

    ReplyDelete
  28. UnknownJune 04, 2012 6:54 pm

    Thanks very much dude, The solution worked for me.

    ReplyDelete
  29. AnonymousJune 05, 2012 9:04 am

    I have been developing in this stable Indigo environment for a long time and just installed VeloEclipse plugin from Marketplace without any issue. On restart I got this error. Removing and readd JRE made it go away. Don't know what I would have done if I didn't find this post.

    ReplyDelete
  30. AnonymousJune 06, 2012 8:03 pm

    Thanks a ton. Worked like a charm.

    ReplyDelete
  31. AnonymousJune 06, 2012 9:34 pm

    Thanks for this resolving!!! It's worked today.

    ReplyDelete
  32. UnknownJune 21, 2012 5:30 pm

    Thank You, the solution worked.

    ReplyDelete
  33. Stavan MehtaJuly 19, 2012 3:02 pm

    Thanks. It works for me :)

    ReplyDelete
  34. UnknownSeptember 05, 2012 3:31 pm

    Thanks for this easy and workfull answer. This solution worked for me!

    ReplyDelete
  35. AnonymousSeptember 06, 2012 4:53 pm

    Worked for me as well. Thank you

    ReplyDelete
  36. I screwed upOctober 06, 2012 8:20 am

    I was stuck on it for hours... and this just solved it in a minute.. Can't thank you enough

    ReplyDelete
  37. AnonymousJanuary 22, 2013 1:18 pm

    worked for me too thanks for the input

    ReplyDelete
  38. nalFebruary 06, 2013 12:49 am

    Thanks a lot.It works for me..:)

    ReplyDelete
  39. nalFebruary 06, 2013 12:50 am

    Thanks for the solution..it works for me :)

    ReplyDelete
  40. UnknownMay 16, 2013 6:53 pm

    thz so much. It works great!!! :)

    ReplyDelete
  41. AnonymousJune 14, 2013 11:48 am

    Thank you!!!
    This is work for me :")

    ReplyDelete
  42. AnsurajJuly 23, 2015 2:14 am

    Thank you. :)

    ReplyDelete