ClassNotFoundException in NetCDF ImageMosaic when upgrading to geoserver 2.28

hyperman · November 5, 2025, 12:44pm

I have a NetCDF ImageMosaic that’s working on geoserver 2.27.2. When upgrading to 2.28, doing a WCS GetCoverage on it returns this error:

Cannot invoke &amp;quot;org.eclipse.imagen.ImageLayout.getSampleModel(java.awt.image.RenderedImage)&amp;quot; because &amp;quot;this.layout&amp;quot; is null</ows:ExceptionText>

and writes this in the logs:

2025-11-03T10:13:47.728Z WARN   [gce.imagemosaic] - Unable to parse sample image for path /data/geoserver/coverages/emodnet_biology/cal_fin/cal_fin_19582016_L1sample_image.dat
java.lang.ClassNotFoundException: com.sun.media.jai.codecimpl.util.FloatDoubleColorModel
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:467)
at org.geotools.gce.imagemosaic.RemappingFilteringObjectInputStream.load(RemappingFilteringObjectInputStream.java:94)
at org.geotools.gce.imagemosaic.RemappingFilteringObjectInputStream.resolveClass(RemappingFilteringObjectInputStream.java:140)
at java.base/java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:2034)
at java.base/java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1898)
025-11-03T10:13:47.728Z WARN   [gce.imagemosaic] - Unable to find sample image for path file:/data/geoserver/coverages/emodnet_biology/cal_fin/datastore.properties

It seems the coverages have a few files *sample_image.dat, containing a serialized object. As 2.28 has changed the JAI implementation, these objects can’t deserialize anymore. I presume geoserver’s RemappingFilteringObjectInputStream tries to translate these to new classes, but this one is not translated (and I haven’t yet found its successor).

I have unfortunately no knowledge about how these files were created originally. I tried deleting them, but geoserver does not recreate them. There seems to be code in geoserver to rebuild it, but I don’t manage to trigger it without damaging other metadata.

aaime-geosolutions · November 5, 2025, 12:56pm

Interesting,
Could you open a Jira ticket and attach the sample image you have?
Or, if you have a opportunity to make a pull request, the idea is to remap that class to the ImageN class bearing the same name (but a different package, of course)

Regards,

Andrea Aime

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Il mer 5 nov 2025, 07:49 hyperman via OSGeo Discourse <noreply@discourse.osgeo.org> ha scritto:

hyperman
November 5

I have a NetCDF ImageMosaic that’s working on geoserver 2.27.2. When upgrading to 2.28, doing a WCS GetCoverage on it returns this error:

Cannot invoke &quot;org.eclipse.imagen.ImageLayout.getSampleModel(java.awt.image.RenderedImage)&quot; because &quot;this.layout&quot; is null</ows:ExceptionText>

and writes this in the logs:

2025-11-03T10:13:47.728Z WARN [gce.imagemosaic] - Unable to parse sample image for path /data/geoserver/coverages/emodnet_biology/cal_fin/cal_fin_19582016_L1sample_image.dat
java.lang.ClassNotFoundException: com.sun.media.jai.codecimpl.util.FloatDoubleColorModel
at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(BuiltinClassLoader.java:641)
at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(ClassLoaders.java:188)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
at java.base/java.lang.Class.forName0(Native Method)
at java.base/java.lang.Class.forName(Class.java:467)
at org.geotools.gce.imagemosaic.RemappingFilteringObjectInputStream.load(RemappingFilteringObjectInputStream.java:94)
at org.geotools.gce.imagemosaic.RemappingFilteringObjectInputStream.resolveClass(RemappingFilteringObjectInputStream.java:140)
at java.base/java.io.ObjectInputStream.readNonProxyDesc(ObjectInputStream.java:2034)
at java.base/java.io.ObjectInputStream.readClassDesc(ObjectInputStream.java:1898) 2025-11-03T10:13:47.728Z WARN [gce.imagemosaic] - Unable to find sample image for path file:/data/geoserver/coverages/emodnet_biology/cal_fin/datastore.properties

It seems the coverages have a few files *sample_image.dat, containing a serialized object. As 2.28 has changed the JAI implementation, these objects can’t deserialize anymore. I presume geoserver’s RemappingFilteringObjectInputStream tries to translate these to new classes, but this one is not translated (and I haven’t yet found its successor).

I have unfortunately no knowledge about how these files were created originally. I tried deleting them, but geoserver does not recreate them. There seems to be code in geoserver to rebuild it, but I don’t manage to trigger it without damaging other metadata.

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hyperman · November 5, 2025, 1:15pm

Thanks. I think I know the correct remapping. I’ll try and recompile the source code later this week.

hyperman · November 5, 2025, 2:44pm

I have to modify geotools, not geoserver. Want me to stop discussing here and switch to the other forum?
Checking out a new geotools and running mvn install unfortunately gives me test failures even if I don’t modify everything. So sending you a patch will be non-trivial until I’ve found out why. I can do mvn -DskipTests clean install .
When I modify this location:

github.com/geotools/geotools

modules/plugin/imagemosaic/src/main/java/org/geotools/gce/imagemosaic/Utils.java

b07b3543d


      
          // do we have the sample image??
          if (Utils.checkFileReadable(sampleImageFile)) {
              try (FileInputStream fis = new FileInputStream(sampleImageFile);
                      RemappingFilteringObjectInputStream oiStream = RemappingFilteringObjectInputStream.builder()
                              .input(fis)
                              .accept(SAMPLE_IMAGE_CLASSES)
                              .acceptPattern(SAMPLE_IMAGE_PATTERNS)
                              .accept(SAMPLE_IMAGE_PRIMITIVES)
                              .accept(sampleImageAllowList)
                              .remapPackage("javax.media.jai", "org.eclipse.imagen")
                              .remapPackage("com.sun.media.jai.rmi", "org.eclipse.imagen.media.serialize")
                              .build()) {
                  // load the image
                  Object object = oiStream.readObject();
                  if (object instanceof SampleImage si) {
                      return si.toBufferedImage();
                  } else {
                      LOGGER.warning(() -> "Unrecognized sample image content '"
                              + object.getClass().getName() + "' for path " + sampleImageFile);
                      return null;
                  }

and add this line:

.remapPackage("com.sun.media.jai.codecimpl.util", "org.eclipse.imagen")

the problem seems fixed.

aaime-geosolutions · November 5, 2025, 3:02pm

Excellent. Could you turn that into a pull request?

There is already a migration test, if you add your sample file in there and check it, that would be all that’s needed to merge the code change.

Cheers
Andrea

hyperman · November 6, 2025, 12:33pm

PR and issue are ready. I’ve gone trough other similar layers, and no other ClassNotFoundExceptions appear.

github.com/geotools/geotools

[GEOT-7831] Fix missing package mapping after JAI migration

main ← hyperman3:main

opened 12:29PM - 06 Nov 25 UTC

hyperman3

+9 -0

[![GEOT-7831](https://badgen.net/badge/JIRA/GEOT-7831/0052CC)](https://osgeo-org….atlassian.net/browse/GEOT-7831) [<img width="16" alt="Powered by Pull Request Badge" src="https://user-images.githubusercontent.com/1393946/111216524-d2bb8e00-85d4-11eb-821b-ed4c00989c02.png">](https://pullrequestbadge.com/?utm_medium=github&utm_source=geotools&utm_campaign=badge_info) # Checklist - [X] I have read the [contribution guidelines](https://github.com/geotools/geotools/blob/main/CONTRIBUTING.md). - [ ] I have sent a [Contribution Licence Agreement](https://docs.geotools.org/latest/developer/procedures/contribution_license.html) (not required for small changes, e.g., fixing typos in documentation). - [X] First PR targets the `main` branch (backports managed later; ignore for branch specific issues). - [X] Avoid [Java 9+ split packages](http://tutorials.jenkov.com/java/modules.html#split-packages-not-allowed). - [X] All the build checks are green ([see automated QA checks](https://docs.geotools.org/latest/developer/conventions/code/qa.html)). For core and extension modules: - [X] New unit tests have been added covering the changes. - [ ] [Documentation](https://github.com/geotools/geotools/tree/main/docs) has been updated (if change is visible to end users). - [X] There is an issue in [GeoTools Jira](https://osgeo-org.atlassian.net/projects/GEOT) (except for changes not visible to end users). - [X] Commit message(s) must be in the form ``[GEOT-XYZW] Title of the Jira ticket``. - [X] Bug fixes and small new features are presented as a single commit. - [X] The commit targets a single objective (if multiple focuses cannot be avoided, each one is in its own commit, and has a separate ticket describing it).