Re: CLASSPATH problems

[Blair Wyman <blairw@xxxxxxxxxx>]

There was a pretty fundamental change in how CLASSPATH works -- from JDK
1.1.x to JDK 1.2 (a/k/a "Java 2") -- in that the "system" portions of the
CLASSPATH were moved into their own special location.  This is a really
Great Thing, actually, in that the CLASSPATH can become what was intended
-- a "user" CLASSPATH.  It is still possible to muck with the boot
classpath, using the -Xbootclasspath option, but it is no less a Bad Idea
to do so.

The class path entries used by the JDK itself were moved to a separate
location -- to see them you can look at the "sun.boot.class.path" property.
Here's a modified version of your program that includes this additional
output:
class ShowMeClasspath {
  public static void main(String[] args)
  {
    System.out.println("VERSION=" + System.getProperty("java.version"));
    System.out.println("CLASSPATH=" +
System.getProperty("java.class.path"));
    System.out.println("BOOTCLASSPATH=" +
System.getProperty("sun.boot.class.path","--NOT SET--"));
  }
}

(Note the two-string form of System.getProperty, where the second value
("--NOT SET--") is the "default" to return if the property isn't set for
the JVM.  This should allow the program to run fine on either JDK1.1.x or
JDK1.2+...)

On a related note, to get a different JDK version of the javac compiler
itself (or other tools such as rmic, javap, etc.) you use the -J flag to
pass the "java.version" property to the JVM the tool uses.  For instance,
to use the JDK1.3 version of the compiler to compile ShowMeClasspath.java,
you would use:

      javac -J-Djava.version=1.3 ShowMeClasspath.java

HTH.

-blair

Blair Wyman -- iSeries JVM -- (507) 253-2891
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"It is a sobering thought that when Mozart was my age,
he had been dead for two years." -- Tom Lehrer



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  |       Subject:  CLASSPATH problems                                          
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We are still on V4R5.  This is the Java part of our installed licensed
programs:
5769JC1    *BASE   AS/400 Toolbox for Java
5769JV1    *BASE   AS/400 Developer Kit for Java
5769JV1    1       Java Developer Kit 1.1.6
5769JV1    2       Java Developer Kit 1.1.7
5769JV1    3       Java Developer Kit 1.2
5769JV1    4       Java Developer Kit 1.1.8
5769JV1    5       Java Developer Kit 1.3

With no systemdefault.properties file anywhere, the default in Qshell
shows:

java -version
java version "1.1.8"

compiling and running the ShowMeClasspath java program shows:

java ShowMeClasspath
CLASSPATH=/QIBM/ProdData/Java400/jdk118/lib/jdkptf118.zip:/QIBM/ProdData/Jav

a400/jdk118/lib/classes.zip:/QIBM/ProdData/Java400/ex
t/IBMmisc.jar:/QIBM/ProdData/Java400/ext/db2_classes.jar:/QIBM/ProdData/Java

400/ext/jssl.jar:/QIBM/ProdData/Java400/ext/ibmjssl.j
ar:/QIBM/ProdData/Java400/jt400ntv.jar:/QIBM/ProdData/Java400/:.:/home/jdunn


I have set a *JOB environment variable as:    .:/home/jdunn
------------------------------------------------------------------
The problem:

When I try using the 1.3 JDK (or the 1.2 JDK), the following happens:

java -Djava.version=1.3 ShowMeClasspath
CLASSPATH=.:/home/jdunn

setting up a systemdefault.properties file in my home directory
(/home/jdunn) with:

java.version=1.3

I get the following:

java -version
java version "1.3.0"
$
java ShowMeClasspath
CLASSPATH=.:/home/jdunn

I have seen some posts about V4R5 and the 1.3 JDK, but no resolutions.  It
seems like the "system" portion of the CLASSPATH doesn't get "loaded" if I
try to use any JDK other that 1.1.8.  The defective CLASSPATH is a problem
when I try to compile a java program using 1.3.  I get all sorts of:

javac ShowMeClasspath.java
ShowMeClasspath.java:2: cannot resolve symbol
symbol  : class String
location: class ShowMeClasspath
public static void main(String[] args)
                                  ^

that does NOT happen when I use the default 1.1.8 environment.  Could
someone help me?  If someone does have JDK 1.3 working successfully on
V4R5,
could you compile and run ShowMeClasspath.java and post the output?

ShowMeClasspath.java:

class ShowMeClasspath {
public static void main(String[] args)
{
System.out.println("CLASSPATH=" +System.getProperty("java.class.path"));
}
}


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