A version of jaxb-xjc.jar used by NetBeans seems to break pack200 on JDK 7, so that unpack200 (on either JDK 6 or 7) fails with the error message "null ref". pack200 from JDK 6 processes the file correctly, or at least enough that unpack200 on either JDK completes normally.

I run 64-bit Ubuntu and normally use 32-bit JVMs. But the 64-bit JVM seems to have the same problem.

$ curl -s http://hg.netbeans.org/binaries/64D468922B85A9626178AEDF564FFDBDE980B3EC-jaxb-xjc.jar > jaxb-xjc-orig.jar
$ uname -a
Linux jglick-t400 3.0.0-14-generic #23-Ubuntu SMP Mon Nov 21 20:28:43 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux
$ /space/jdk6/bin/pack200 -J-showversion jaxb-xjc-jdk6.jar.pack.gz jaxb-xjc-orig.jar
java version "1.6.0_30"
Java(TM) SE Runtime Environment (build 1.6.0_30-b12)
Java HotSpot(TM) Server VM (build 20.5-b03, mixed mode)

$ /space/jdk7/bin/pack200 -J-showversion jaxb-xjc-jdk7.jar.pack.gz jaxb-xjc-orig.jar
java version "1.7.0_02"
Java(TM) SE Runtime Environment (build 1.7.0_02-b13)
Java HotSpot(TM) Server VM (build 22.0-b10, mixed mode)

$ /space/jdk6/bin/unpack200 jaxb-xjc-jdk6.jar.pack.gz jaxb-xjc-jdk6.jar
$ jar tvf jaxb-xjc-jdk6.jar | head
     0 Wed Nov 04 07:57:18 EST 2009 META-INF/
   588 Wed Nov 04 07:57:16 EST 2009 META-INF/MANIFEST.MF
     0 Tue Mar 04 09:59:12 EST 2008 META-INF/maven/
     0 Tue Mar 04 09:59:12 EST 2008 META-INF/maven/com.sun.codemodel/
     0 Tue Mar 04 09:59:12 EST 2008 META-INF/maven/com.sun.codemodel/codemodel/
     0 Fri Oct 23 08:37:24 EDT 2009 com/
     0 Fri Oct 23 08:37:24 EDT 2009 com/sun/
     0 Wed Nov 04 07:57:14 EST 2009 com/sun/codemodel/
     0 Wed Nov 04 07:57:14 EST 2009 com/sun/codemodel/fmt/
     0 Wed Nov 04 07:57:14 EST 2009 com/sun/codemodel/util/
$ /space/jdk7/bin/unpack200 jaxb-xjc-jdk7.jar.pack.gz jaxb-xjc-jdk7.jar
null ref
$ echo $?
255
$ jar tvf jaxb-xjc-jdk7.jar | head
java.util.zip.ZipException: error in opening zip file
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(ZipFile.java:214)
at java.util.zip.ZipFile.<init>(ZipFile.java:144)
at java.util.zip.ZipFile.<init>(ZipFile.java:115)
at sun.tools.jar.Main.list(Main.java:1004)
at sun.tools.jar.Main.run(Main.java:245)
at sun.tools.jar.Main.main(Main.java:1177)
$ /space/jdk1.7.0_01_64/bin/pack200 -J-showversion jaxb-xjc-jdk764.jar.pack.gz jaxb-xjc-orig.jar
java version "1.7.0_01"
Java(TM) SE Runtime Environment (build 1.7.0_01-b08)
Java HotSpot(TM) 64-Bit Server VM (build 21.1-b02, mixed mode)

$ /space/jdk1.7.0_01_64/bin/unpack200 jaxb-xjc-jdk764.jar.pack.gz jaxb-xjc-jdk764.jar
null ref
$ /space/jdk7/bin/unpack200 jaxb-xjc-jdk6.jar.pack.gz jaxb-xjc-jdk627.jar
$ jar tvf jaxb-xjc-jdk627.jar | head
     0 Wed Nov 04 07:57:18 EST 2009 META-INF/
   588 Wed Nov 04 07:57:16 EST 2009 META-INF/MANIFEST.MF
     0 Tue Mar 04 09:59:12 EST 2008 META-INF/maven/
     0 Tue Mar 04 09:59:12 EST 2008 META-INF/maven/com.sun.codemodel/
     0 Tue Mar 04 09:59:12 EST 2008 META-INF/maven/com.sun.codemodel/codemodel/
     0 Fri Oct 23 08:37:24 EDT 2009 com/
     0 Fri Oct 23 08:37:24 EDT 2009 com/sun/
     0 Wed Nov 04 07:57:14 EST 2009 com/sun/codemodel/
     0 Wed Nov 04 07:57:14 EST 2009 com/sun/codemodel/fmt/
     0 Wed Nov 04 07:57:14 EST 2009 com/sun/codemodel/util/
$ /space/jdk6/bin/unpack200 jaxb-xjc-jdk7.jar.pack.gz jaxb-xjc-jdk726.jar
null ref
$ jar tvf jaxb-xjc-jdk726.jar | head
java.util.zip.ZipException: error in opening zip file
at java.util.zip.ZipFile.open(Native Method)
at java.util.zip.ZipFile.<init>(ZipFile.java:214)
at java.util.zip.ZipFile.<init>(ZipFile.java:144)
at java.util.zip.ZipFile.<init>(ZipFile.java:115)
at sun.tools.jar.Main.list(Main.java:1004)
at sun.tools.jar.Main.run(Main.java:245)
at sun.tools.jar.Main.main(Main.java:1177)