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Re: Why Doesn't my Code Work with this Jar File?

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On 11-11-01 11:14 PM, Arne Vajhøj wrote:
> On 11/1/2011 7:59 PM, Lew wrote:
>> Arved Sandstrom wrote:
>>> KevinSimonson wrote:
>>>> I'm having a nasty time figuring out how to use JAR files.  I have a
>>>> directory "Jrs" that includes an "abc" directory and a "def"
>>>> directory.  In directory "abc" I have a single file called
>>>> "AbcCl.java" coded:
>>>>
>>>> package abc;
>>>> public class AbcCl
>>>> {
>>>>    public String toString ()
>>>>    {
>>>>      return "[AbcCl Object]";
>>>>    }
>>>> }
>>>>
>>>> and in directory "def" I have a single file called "DefCl.java" coded:
>>>>
>>>> package def;
>>>> public class DefCl
>>>> {
>>>>    public String toString ()
>>>>    {
>>>>      return "[DefCl Object]";
>>>>    }
>>>> }
>>>>
>>>> Back in "Jrs" I have a file "UseEm.java" coded:
>>>>
>>>> import abc.AbcCl;
>>>> import def.DefCl;
>>>>
>>>> public class UseEm
>>>> {
>>>>    public static void main ( Strin[] arguments)
>>>>    {
>>>>      AbcCl ac = new AbcCl();
>>>>      DefCl dc = new DefCl();
>>>>      System.out.println( "ac == " + ac + ", dc == " + dc + '.');
>>>>    }
>>>> }
>>>>
>>>> Then I executed "javac UseEm.java", which created three class files,
>>>> an "abc\AbcCl.class", a "def\DefCl.class", and a "UseEm.java".
>>>> Finally I created two jar files with commands "jar -cf abc.jar abc"
>>>> and "jar -cf def.jar def".
>>>>
>>>> Then I created a "Jrs2" directory, a sibiling to "Jrs", and copied to
>>>> it "UseEm.java" and the two JAR files.  In that "Jrs2" directory I
>>>> typed in the command "javac -cp abc.jar:def.jar", and as a result got
>>>> a whole bunch of error messages.  I was kind of expecting that.
>>>>
>>>> At that point I typed in "jar -xf abc.jar" which extracted the "abc"
>>>> directory, and I thought that therefore I should be able to compile
>>>> "UseEm.java" with the command "javac -cp .:def.jar UseEm.java".  But
>>>> when I tried it I got error messages:
>>> [ SNIP ]
>>>
>>>> 6 errors
>>>>
>>>> Does anybody have any idea what I'm doing wrong?  Why can't I get the
>>>> code I need to compile out of this JAR file?  And _why in the world_
>>>> can't my compiler see the<AbcCl>  class?  The "abc" directory is
>>>> _right there_, with an "AbcCl.class" and an "AbcCl.java" file right in
>>>> it?
>>>
>>> With the exception of the manual typo in UseEm.java, the only thing
>>> wrong with your procedure is that you should also have supplied '.' as
>>> part of the classpath on your first javac attempt with the JARs
>>> (otherwise javac doesn't know where UseEm.java is). But that absolutely
>>> should have worked.
>>>
>>> I know it should have because I just now did it. I always do just to
>>> make sure there's nothing catching me out in a question. The only
>>> difference is that I don't include *.java files in JARs.
>>>
>>> Side note: 'jar' does not need a hyphen in front of its arguments, and
>>> never has.
>>
>> As another side note, do not mix classes that are in packages with
>> classes that are not.
> 
> When one is ready to build jar files, then it may be time to drop
> default package completely.
> 
> Arne
> 
That's good advice for the OP. I don't use the default package either.

In this case, though, with the imported classes being in named packages,
various quirks of the default package do not interfere with compiling
and running the OP's example. Hence it would be interesting to find out
what is causing the OP's problem.

AHS
-- 
You should know the problem before you try to solve it.
Example: When my son was three he cried about a problem with his hand. I
kissed it several times and asked him about the problem. He peed on his
hand.
-- Radia Perlman, inventor of spanning tree protocol

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Why Doesn't my Code Work with this Jar File? KevinSimonson <kvnsmnsn@hotmail.com> - 2011-11-01 10:39 -0700
  Re: Why Doesn't my Code Work with this Jar File? markspace <-@.> - 2011-11-01 11:23 -0700
  Re: Why Doesn't my Code Work with this Jar File? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-11-01 20:21 -0300
    Re: Why Doesn't my Code Work with this Jar File? Lew <lewbloch@gmail.com> - 2011-11-01 16:59 -0700
      Re: Why Doesn't my Code Work with this Jar File? Arne Vajhøj <arne@vajhoej.dk> - 2011-11-01 22:14 -0400
        Re: Why Doesn't my Code Work with this Jar File? Arved Sandstrom <asandstrom3minus1@eastlink.ca> - 2011-11-02 07:13 -0300
          Re: Why Doesn't my Code Work with this Jar File? KevinSimonson <kvnsmnsn@hotmail.com> - 2011-11-02 16:44 -0700
            Re: Why Doesn't my Code Work with this Jar File? markspace <-@.> - 2011-11-02 18:16 -0700
          Re: Why Doesn't my Code Work with this Jar File? Arne Vajhøj <arne@vajhoej.dk> - 2011-11-02 20:00 -0400
  Re: Why Doesn't my Code Work with this Jar File? Roedy Green <see_website@mindprod.com.invalid> - 2011-11-03 00:47 -0700
  Re: Why Doesn't my Code Work with this Jar File? Roedy Green <see_website@mindprod.com.invalid> - 2011-11-03 00:50 -0700

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