Name: skT45625 Date: 07/26/2000


java version "1.3.0"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.3.0-C)
Java HotSpot(TM) Client VM (build 1.3.0-C, mixed mode)java

When using the "Main-Class" feature of a jar's manifest file and the "-jar"
option to java.exe, the classpath environment variable seems to be ignored. I
have created a testcase:

Other.java:
-------------------------------------------------
    public class Other { }
-------------------------------------------------

Main.java:
-------------------------------------------------
    public class Main
    {
        public static void main (String [] args)
        {
            Other other = new Other();
        }
    }
------------------------------------

manifest:
------------------------------------
    Manifest-Version: 1.0
    Main-Class: Main
-------------------------------------

Instructions for setting up the test:
1. Create the files "Other.java", "Main.java", and "manifest" with the contents
listed above.
2. javac Main.java
3. javac Other.java
4. jar -cf other.jar Other.class
5. jar -cfm main.jar manifest Main.class

Now, execute this sequence of commands:

    SET CLASSPATH=other.jar
    java -jar main.jar
    
    SET CLASSPATH=other.java;main.java
    java Main

    java -cp other.jar;main.jar Main

In the first execution, there is an exception:

    Exception in thread "main" java.lang.NoClassDefFoundError: Other

even though class Other is in the classpath. The other two commands run
correctly (no exceptions, no output, as expected). It seems that the "-jar"
option is causing java.exe to ignore the classpath, which is incorrect: the
classpath should be used like it is in the last two example executions.

It is possible to use the "Class-Path" header field name in the manifest to
work around this issue. This is inappropriate for many applications for because
the "Class-Path" header field requires the JAR creator to know the location of
the classes it depends on. The application should not have to know the location
of the file.

I noticed this bug when using JAXP. Since I wanted to be able to switch parser
implementations at runtime (one of the goals of JAXP), I did not know the
locations of the SAX classes: they could be in "parsers.jar" or "xerces.jar"
or "xml4j.jar", for example. Because of this I could not put the "Class-Path"
header in my JAR file to reference any one of these. I can send a more
elaborate testcase that uses JAXP to demonstrate this problem if needed.
(Review ID: 107498)
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