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4 Replies Latest reply: Oct 30, 2012 8:53 PM by 829510 RSS

how can i remove jdk1.4 install in oracle unbreakable linux.

829510 Newbie
Currently Being Moderated
I am able to comple java program in oracle unbreakable linux but not able to run program.this is simple hello world program there is no syntax problem .I am getting error:

Exception in thread Main java.lang.class format error:unrecognised class file version and i also checked :=> #javac -version
#jdk1.6_20
#java -version
#jadk1.4 (gnu support java)
How can i unstall jdk1.4 gnu jdk/bin path and jdk 1.4 gnu java from with my system.
Regards
Prashansh Kumar
  • 1. Re: how can i remove jdk1.4 install in oracle unbreakable linux.
    Dude! Guru
    Currently Being Moderated
    From what I understand, the problem is that your classes are compiled for a later version of Java. I'm not sure at this point that uninstalling Java 1.4 is the right solution - it may break important system functions.

    I would rather try another approach first:

    # alternatives --config java
    -> select the java version you want as default.
    If you want to install java 1.6 you can try the following:
    # yum install java-1.6*
    or just the runtime package
    # yum install java-1.6.0-openjdk
    
    For example:
    
    # java -version
    java version "1.4.2"
    
    # yum install java-1.6.0-openjdk
    # alternatives --config java
    
    There are 2 programs which provide 'java'.
    
      Selection    Command
    -----------------------------------------------
     + 1           /usr/lib/jvm/jre-1.4.2-gcj/bin/java
    *  2           /usr/lib/jvm/jre-1.6.0-openjdk.x86_64/bin/java
    
    Enter to keep the current selection[+], or type selection number: 2
    
    # java -version
    java version "1.6.0"
  • 2. Re: how can i remove jdk1.4 install in oracle unbreakable linux.
    829510 Newbie
    Currently Being Moderated
    Dear Dude

    I installed jdk1.6 rather than java run time environment.I already installed jdk1.6.I am able to compile with
    javac program.java but i am not able to run java program with this command java program.

    regards
    Prasathi
  • 3. Re: how can i remove jdk1.4 install in oracle unbreakable linux.
    Dude! Guru
    Currently Being Moderated
    What I was wondering about: You compiled with java 1.6, but java -version still reports 1.4. I think your problem is that you will also need to use java 1.6. From what I understand, uninstalling java 1.4 does not mean it will automatically switch to 1.6. But you could try to choose and change your default java to be 1.6 as I outlined above.

    To uninstall 1.4 I suppose you could try sudo yum remove java-1.4*, but I would rather try to simply switch the default java first.

    Edited by: Dude on Apr 15, 2011 1:09 AM
  • 4. Re: how can i remove jdk1.4 install in oracle unbreakable linux.
    829510 Newbie
    Currently Being Moderated
    Answered.Please lock this thread.

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