[BUG] NullPointerException in ThreddsHarvester.extractMetadataFromOpendapDDX (4.2.2 & 4.4.4)

[gdauden]

Subject: NullPointerException in ThreddsHarvester.extractMetadataFromOpendapDDX (4.2.2 & 4.4.4)

Description of the problem:
When attempting to harvest a THREDDS catalog using the "THREDDS" harvester type in GeoNetwork, a recurring NullPointerException occurs in the extractMetadataFromOpendapDDX method. This error prevents the successful harvesting of dataset metadata.

Affected versions:
We have consistently replicated this behavior in GeoNetwork 4.2.2 and 4.4.4.

Steps to reproduce:

1. Deploy a GeoNetwork instance (in our case, using Docker Compose, version 4.2.2).
2. Log in to the GeoNetwork administration interface.
3. Create a new harvester of type "THREDDS".
4. Configure the THREDDS catalog URL: http://172.16.132.22:8004/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2025/catalog.xml
5. Ensure that the custom XSLT ThreddsCatalog-to-ISO19119_ISO19139.xsl is correctly located at /var/lib/jetty/webapps/geonetwork/WEB-INF/data/config/schema_plugins/iso19139/convert/ and referenced in schema-conversions.xml for the conversion from="thredds" to iso19139.
6. Execute the harvester.

Expected behavior:
The harvester should process the THREDDS catalog, apply the XSLT transformation, and import the ISO 19139 metadata without errors.

Observed behavior (with DEBUG logs):
The harvester starts, reads the main THREDDS catalog, but when attempting to process individual datasets and access the OPeNDAP DDX service, it throws a NullPointerException. The detailed logs indicate that GeoNetwork successfully accesses the DDX XML, but the error occurs during its internal processing of this DDX. A second NullPointerException in Xml.transform is observed, which appears to be a consequence of the first.

Relevant log snippet:

2025-07-16T11:13:01,262 INFO  [geonetwork.harvester] - Starting harvesting of gn422_threddsmiguel
2025-07-16T11:13:01,282 INFO  [geonetwork.harvester] - Started harvesting from node : gn422_threddsmiguel (ThreddsHarvester)
2025-07-16T11:13:01,284 INFO  [geonetwork.harvester] - Retrieving remote metadata information for : gn422_threddsmiguel
catalog valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2025/dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20_data_rt.nc valid = true
dataset dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2025/dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20.nc valid = true
dataset dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2025/dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09_data_rt.nc valid = true
dataset dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2025/dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09.nc valid = true
dataset dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09.nc valid = true
dataset 2025 valid = true
2025-07-16T11:13:01,376 INFO  [geonetwork.harvester] - Catalog read from http://172.16.132.22:8004//thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2025/catalog.xml is

2025-07-16T11:13:01,376 INFO  [geonetwork.harvester] - Crawling the datasets in the catalog....
2025-07-16T11:13:01,377 INFO  [geonetwork.harvester] - Crawling through 2025
2025-07-16T11:13:01,377 INFO  [geonetwork.harvester] - Trying to find ThreddsMetadata for dataset 2025
2025-07-16T11:13:01,377 INFO  [geonetwork.harvester] - Crawling through dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20_data_rt.nc
2025-07-16T11:13:01,377 INFO  [geonetwork.harvester] - Processing dataset: dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20_data_rt.nc with URL: http://172.16.132.22:8004//thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2025/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2025%2Fdep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20_data_rt.nc
2025-07-16T11:13:01,492 ERROR [geonetwork.harvester] - Thrown Exception java.lang.NullPointerException during dataset processing
java.lang.NullPointerException
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.extractMetadataFromOpendapDDX(Harvester.java:1364)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.getMetadata(Harvester.java:864)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.examineThreddsDataset(Harvester.java:604)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:462)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:458)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvestCatalog(Harvester.java:411)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvest(Harvester.java:284)
at org.fao.geonet.kernel.harvest.harvester.thredds.ThreddsHarvester.doHarvest(ThreddsHarvester.java:76)
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvesterHarvestWithIndexProcessor.process(AbstractHarvester.java:602)atorg.fao.geonet.kernel.harvest.harvester.AbstractHarvester.harvest(AbstractHarvester.java:673)atorg.fao.geonet.kernel.harvest.harvester.HarvesterJob.execute(HarvesterJob.java:69)atorg.quartz.core.JobRunShell.run(JobRunShell.java:202)atorg.quartz.simpl.SimpleThreadPoolWorkerThread.run(SimpleThreadPool.java:573)
2025-07-16T11:13:01,493 INFO  [geonetwork.harvester] - Processing service: http://172.16.132.22:8004/thredds/iso/ for dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20_data_rt.nc
2025-07-16T11:13:01,493 INFO  [geonetwork.harvester] - Crawling through dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20.nc
2025-07-16T11:13:01,494 INFO  [geonetwork.harvester] - Processing dataset: dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20.nc with URL: http://172.16.132.22:8004//thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2025/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2025%2Fdep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20.nc
2025-07-16T11:13:01,546 ERROR [geonetwork.harvester] - Thrown Exception java.lang.NullPointerException during dataset processing
java.lang.NullPointerException
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.extractMetadataFromOpendapDDX(Harvester.java:1364)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.getMetadata(Harvester.java:864)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.examineThreddsDataset(Harvester.java:604)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:462)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:458)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvestCatalog(Harvester.java:411)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvest(Harvester.java:284)
at org.fao.geonet.kernel.harvest.harvester.thredds.ThreddsHarvester.doHarvest(ThreddsHarvester.java:76)
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvesterHarvestWithIndexProcessor.process(AbstractHarvester.java:602)atorg.fao.geonet.kernel.harvest.harvester.AbstractHarvester.harvest(AbstractHarvester.java:673)atorg.fao.geonet.kernel.harvest.harvester.HarvesterJob.execute(HarvesterJob.java:69)atorg.quartz.core.JobRunShell.run(JobRunShell.java:202)atorg.quartz.simpl.SimpleThreadPoolWorkerThread.run(SimpleThreadPool.java:573)
2025-07-16T11:13:01,547 INFO  [geonetwork.harvester] - Processing service: http://172.16.132.22:8004/thredds/iso/ for dep0010_sl3u1064_scb-sl3u1064_L1_2025-05-20.nc
2025-07-16T11:13:01,547 INFO  [geonetwork.harvester] - Crawling through dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09_data_rt.nc
2025-07-16T11:13:01,547 INFO  [geonetwork.harvester] - Processing dataset: dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09_data_rt.nc with URL: http://172.16.132.22:8004//thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2025/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2025%2Fdep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09_data_rt.nc
2025-07-16T11:13:01,606 ERROR [geonetwork.harvester] - Thrown Exception java.lang.NullPointerException during dataset processing
java.lang.NullPointerException
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.extractMetadataFromOpendapDDX(Harvester.java:1364)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.getMetadata(Harvester.java:864)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.examineThreddsDataset(Harvester.java:604)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:462)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:458)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvestCatalog(Harvester.java:411)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvest(Harvester.java:284)
at org.fao.geonet.kernel.harvest.harvester.thredds.ThreddsHarvester.doHarvest(ThreddsHarvester.java:76)
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvesterHarvestWithIndexProcessor.process(AbstractHarvester.java:602)atorg.fao.geonet.kernel.harvest.harvester.AbstractHarvester.harvest(AbstractHarvester.java:673)atorg.fao.geonet.kernel.harvest.harvester.HarvesterJob.execute(HarvesterJob.java:69)atorg.quartz.core.JobRunShell.run(JobRunShell.java:202)atorg.quartz.simpl.SimpleThreadPoolWorkerThread.run(SimpleThreadPool.java:573)
2025-07-16T11:13:01,606 INFO  [geonetwork.harvester] - Processing service: http://172.16.132.22:8004/thredds/iso/ for dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09_data_rt.nc
2025-07-16T11:13:01,606 INFO  [geonetwork.harvester] - Crawling through dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09.nc
2025-07-16T11:13:01,607 INFO  [geonetwork.harvester] - Processing dataset: dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09.nc with URL: http://172.16.132.22:8004//thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2025/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2025%2Fdep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09.nc
2025-07-16T11:13:01,663 ERROR [geonetwork.harvester] - Thrown Exception java.lang.NullPointerException during dataset processing
java.lang.NullPointerException
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.extractMetadataFromOpendapDDX(Harvester.java:1364)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.getMetadata(Harvester.java:864)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.examineThreddsDataset(Harvester.java:604)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:462)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.crawlDatasets(Harvester.java:458)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvestCatalog(Harvester.java:411)
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvest(Harvester.java:284)
at org.fao.geonet.kernel.harvest.harvester.thredds.ThreddsHarvester.doHarvest(ThreddsHarvester.java:76)
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvesterHarvestWithIndexProcessor.process(AbstractHarvester.java:602)atorg.fao.geonet.kernel.harvest.harvester.AbstractHarvester.harvest(AbstractHarvester.java:673)atorg.fao.geonet.kernel.harvest.harvester.HarvesterJob.execute(HarvesterJob.java:69)atorg.quartz.core.JobRunShell.run(JobRunShell.java:202)atorg.quartz.simpl.SimpleThreadPoolWorkerThread.run(SimpleThreadPool.java:573)
2025-07-16T11:13:01,664 INFO  [geonetwork.harvester] - Processing service: http://172.16.132.22:8004/thredds/iso/ for dep0009_sl3u1064_scb-sl3u1064_L1_2025-04-09.nc
2025-07-16T11:13:01,665 INFO  [geonetwork.harvester] - Adding dataset metadata...
2025-07-16T11:13:01,665 WARN  [geonetwork.harvester] - Raised exception while harvesting from : gn422_threddsmiguel (ThreddsHarvester)
2025-07-16T11:13:01,665 WARN  [geonetwork.harvester] -  (C) Class    : NullPointerException
2025-07-16T11:13:01,666 WARN  [geonetwork.harvester] -  (C) Message : null
2025-07-16T11:13:01,666 ERROR [geonetwork.harvester] - null
java.lang.NullPointerException: null
at org.fao.geonet.utils.Xml.transform(Xml.java:493) ~[gn-common-4.2.2-0.jar:?]
at org.fao.geonet.utils.Xml.transform(Xml.java:400) ~[gn-common-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.createDatasetMetadata(Harvester.java:1545) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvestCatalog(Harvester.java:420) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvest(Harvester.java:284) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.ThreddsHarvester.doHarvest(ThreddsHarvester.java:76) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvesterHarvestWithIndexProcessor.process(AbstractHarvester.java:602) 
[˜gn−harvesters−4.2.2−0.jar:?]atorg.fao.geonet.kernel.harvest.harvester.AbstractHarvester.harvest(AbstractHarvester.java:673) 
[˜gn−harvesters−4.2.2−0.jar:?]atorg.fao.geonet.kernel.harvest.harvester.HarvesterJob.execute(HarvesterJob.java:69) 
[˜quartz−2.3.2.jar:?]atorg.quartz.core.JobRunShell.run(JobRunShell.java:202) 
[˜ quartz−2.3.2.jar:?]atorg.quartz.simpl.SimpleThreadPoolWorkerThread.run(SimpleThreadPool.java:573) ~[quartz-2.3.2.jar:?]

[juanluisrp]

Related code

core-geonetwork/harvesters/src/main/java/org/fao/geonet/kernel/harvest/harvester/thredds/Harvester.java

Lines 1347 to 1365 in bed9291

	private void extractMetadataFromOpendapDDX(InvDataset ds) {
	try {
	// go to the subset service and get the
	// dataset.xml file as it contains bbox and textent
	InvAccess access = ds.getAccess(ServiceType.OPENDAP);
	String url = access.getStandardUrlName();
	log.info("Opendap url is "+url);
	url += ".ddx";
	Element xml = getXMLResponse(url);
	// add variables to gridVariables
	if (extractDDXVariables(xml)) datasetMetadataObtained = true;
	} catch (Exception e) {
	log.error("Thrown Exception " + e + " during dataset processing");
	e.printStackTrace();
	}
	}

[juanluisrp]

Thank you for your report. Could you provide a URL of a THREDDS server where this is happening?

[gdauden]

Hello Geonetwork/Core-Geonetwork, Thank you very much for the answer. Here is the link to the Thredds server: https://thredds.socib.es/thredds/catalog.html However, we are trying to solve these errors from a copy, internally installed, of the provided Thredds. In this Thredds we have removed all the services but the ISO service. Additionally, in this XML file, the URLs have been modified since an error on the NCDF generation, creates an additional error when harvesting related with the ampersand (&). Thus, URLs like this: http://www.socib.es/?seccion=observingFacilities&facility=glider have been temporarily modified to this: http://www.socib.es/, in order to previously solve the NPE error. Please let me know if you have any questions or need any additional information. best, Gonzalo Daudén Bengoa El jue, 17 jul 2025 a las 9:03, Juan Luis Rodríguez Ponce (< ***@***.***>) escribió:

…

*juanluisrp* left a comment (geonetwork/core-geonetwork#8938) <https://urldefense.com/v3/__https://github.com/geonetwork/core-geonetwork/issues/8938*issuecomment-3082859188__;Iw!!D9dNQwwGXtA!XoKiAf4_FyVci8eIwS_A1uYM24l99Rp4mrzHRK-tAAvw9fN4eKhvqSVLbe1fUAQpY67WL6KD0n3_5XgMpicJ13He$> Thank you for your report. Could you provide a URL of a THREDDS server where this is happening? — Reply to this email directly, view it on GitHub <https://urldefense.com/v3/__https://github.com/geonetwork/core-geonetwork/issues/8938*issuecomment-3082859188__;Iw!!D9dNQwwGXtA!XoKiAf4_FyVci8eIwS_A1uYM24l99Rp4mrzHRK-tAAvw9fN4eKhvqSVLbe1fUAQpY67WL6KD0n3_5XgMpicJ13He$>, or unsubscribe <https://urldefense.com/v3/__https://github.com/notifications/unsubscribe-auth/BUXEND7ENQCJQ2KTB7Q47UL3I5DCXAVCNFSM6AAAAACBU3F7PSVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTAOBSHA2TSMJYHA__;!!D9dNQwwGXtA!XoKiAf4_FyVci8eIwS_A1uYM24l99Rp4mrzHRK-tAAvw9fN4eKhvqSVLbe1fUAQpY67WL6KD0n3_5XgMpgQfZ6eD$> . You are receiving this because you authored the thread.Message ID: ***@***.***>

[gdauden]

Hello @juanluisrp we have been trying to harvest from Thredds 4.6.5 with some modifications on it in GeoNetwork 4.2.2. Despite the efforts, we have not succeeded. You will find the Thredds URL to the specific catalog we have been working with as a test below. Additionally, I am adding the logs and an explanation of why we think these errors appear. We hope this information is useful and it allows you to help us solve this problem. Best Gonzalo.

1.- The catalog: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.html
2.- The Logs: docker logs -f 422_geonetwork_1
2025-07-30T08:33:59,494 INFO [geonetwork.harvester] - Starting harvesting of test_thredds_proxy
2025-07-30T08:33:59,539 INFO [geonetwork.harvester] - Started harvesting from node : test_thredds_proxy (ThreddsHarvester)
2025-07-30T08:33:59,557 INFO [geonetwork.harvester] - Retrieving remote metadata information for : test_thredds_proxy
catalog valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc valid = true
dataset dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc valid = true
dataset dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc valid = true
dataset dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc valid = true
dataset dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc valid = true
dataset dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc valid = true
dataset dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc valid = true
dataset dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc valid = true
dataset dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc valid = true
dataset dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc valid = true
dataset dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc valid = true
dataset dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc valid = true
access auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc valid = true
dataset dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc valid = true
dataset 2024 valid = true
2025-07-30T08:33:59,887 INFO [geonetwork.harvester] - Catalog read from http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml is

baseServices TRAJECTORY 14.30 2024-09-02T02:30:57Z 766.3 2024-09-12T17:31:44Z 67.84 2024-09-02T09:11:30Z 7.986 2024-06-01T14:30:41Z 480.4 2024-06-06T14:10:37Z 49.17 2024-06-05T10:21:46Z 9.141 2024-05-06T02:30:44Z 548.9 2024-05-10T11:51:27Z 53.75 2024-05-08T07:01:50Z 9.956 2024-03-22T09:18:41Z 528.9 2024-03-14T16:21:27Z 61.23 2024-06-26T09:45:10Z

2025-07-30T08:33:59,887 INFO [geonetwork.harvester] - Crawling the datasets in the catalog....
2025-07-30T08:33:59,888 INFO [geonetwork.harvester] - Crawling through 2024
2025-07-30T08:33:59,888 INFO [geonetwork.harvester] - Trying to find ThreddsMetadata for dataset 2024
2025-07-30T08:33:59,888 INFO [geonetwork.harvester] - Crawling through dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:33:59,888 INFO [geonetwork.harvester] - Processing dataset: dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:34:00,356 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:34:00,423 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:34:00,435 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:34:00,435 INFO [geonetwork.harvester] - Crawling through dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc
2025-07-30T08:34:00,436 INFO [geonetwork.harvester] - Processing dataset: dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc
2025-07-30T08:34:09,384 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc
2025-07-30T08:34:09,436 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc
2025-07-30T08:34:09,437 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_dt.nc
2025-07-30T08:34:09,437 INFO [geonetwork.harvester] - Crawling through dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc
2025-07-30T08:34:09,438 INFO [geonetwork.harvester] - Processing dataset: dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc
2025-07-30T08:34:09,571 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc
2025-07-30T08:34:09,614 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc
2025-07-30T08:34:09,614 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01.nc
2025-07-30T08:34:09,615 INFO [geonetwork.harvester] - Crawling through dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc
2025-07-30T08:34:09,615 INFO [geonetwork.harvester] - Processing dataset: dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc
2025-07-30T08:34:09,876 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc
2025-07-30T08:34:09,902 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc
2025-07-30T08:34:09,903 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_rt.nc
2025-07-30T08:34:09,903 INFO [geonetwork.harvester] - Crawling through dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc
2025-07-30T08:34:09,904 INFO [geonetwork.harvester] - Processing dataset: dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc
2025-07-30T08:34:15,249 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc
2025-07-30T08:34:15,288 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc
2025-07-30T08:34:15,289 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16_data_dt.nc
2025-07-30T08:34:15,290 INFO [geonetwork.harvester] - Crawling through dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc
2025-07-30T08:34:15,290 INFO [geonetwork.harvester] - Processing dataset: dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc
2025-07-30T08:34:15,365 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc
2025-07-30T08:34:15,400 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc
2025-07-30T08:34:15,401 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0007_sl3u1064_scb-sl3u1064_L1_2024-05-16.nc
2025-07-30T08:34:15,401 INFO [geonetwork.harvester] - Crawling through dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc
2025-07-30T08:34:15,401 INFO [geonetwork.harvester] - Processing dataset: dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc
2025-07-30T08:34:15,897 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc
2025-07-30T08:34:15,933 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc
2025-07-30T08:34:15,933 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_rt.nc
2025-07-30T08:34:15,933 INFO [geonetwork.harvester] - Crawling through dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc
2025-07-30T08:34:15,934 INFO [geonetwork.harvester] - Processing dataset: dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc
2025-07-30T08:34:22,275 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc
2025-07-30T08:34:22,318 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc
2025-07-30T08:34:22,319 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15_data_dt.nc
2025-07-30T08:34:22,319 INFO [geonetwork.harvester] - Crawling through dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc
2025-07-30T08:34:22,320 INFO [geonetwork.harvester] - Processing dataset: dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc
2025-07-30T08:34:22,392 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc
2025-07-30T08:34:22,417 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc
2025-07-30T08:34:22,418 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0006_sl3u1064_scb-sl3u1064_L1_2024-04-15.nc
2025-07-30T08:34:22,418 INFO [geonetwork.harvester] - Crawling through dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc
2025-07-30T08:34:22,419 INFO [geonetwork.harvester] - Processing dataset: dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc
2025-07-30T08:34:22,679 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc
2025-07-30T08:34:22,712 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc
2025-07-30T08:34:22,712 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_rt.nc
2025-07-30T08:34:22,713 INFO [geonetwork.harvester] - Crawling through dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc
2025-07-30T08:34:22,713 INFO [geonetwork.harvester] - Processing dataset: dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc
2025-07-30T08:34:28,575 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc
2025-07-30T08:34:28,606 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc
2025-07-30T08:34:28,607 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13_data_dt.nc
2025-07-30T08:34:28,607 INFO [geonetwork.harvester] - Crawling through dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc
2025-07-30T08:34:28,607 INFO [geonetwork.harvester] - Processing dataset: dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc with URL: http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml?dataset=auv%2Fglider%2Fsl3u1064-scb_sl3u1064%2FL1%2F2024%2Fdep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc
2025-07-30T08:34:28,681 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc
2025-07-30T08:34:28,715 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc
2025-07-30T08:34:28,716 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0005_sl3u1064_scb-sl3u1064_L1_2024-02-13.nc
2025-07-30T08:34:28,716 INFO [geonetwork.harvester] - Adding dataset metadata...
2025-07-30T08:34:28,719 WARN [geonetwork.harvester] - Raised exception while harvesting from : test_thredds_proxy (ThreddsHarvester)
2025-07-30T08:34:28,719 WARN [geonetwork.harvester] - (C) Class : NullPointerException
2025-07-30T08:34:28,719 WARN [geonetwork.harvester] - (C) Message : null
2025-07-30T08:34:28,720 ERROR [geonetwork.harvester] - null
java.lang.NullPointerException: null
at org.fao.geonet.utils.Xml.transform(Xml.java:493) ~[gn-common-4.2.2-0.jar:?]
at org.fao.geonet.utils.Xml.transform(Xml.java:400) ~[gn-common-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.createDatasetMetadata(Harvester.java:1545) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvestCatalog(Harvester.java:420) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.harvest(Harvester.java:284) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.thredds.ThreddsHarvester.doHarvest(ThreddsHarvester.java:76) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvester$HarvestWithIndexProcessor.process(AbstractHarvester.java:602) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.AbstractHarvester.harvest(AbstractHarvester.java:673) ~[gn-harvesters-4.2.2-0.jar:?]
at org.fao.geonet.kernel.harvest.harvester.HarvesterJob.execute(HarvesterJob.java:69) ~[gn-harvesters-4.2.2-0.jar:?]
at org.quartz.core.JobRunShell.run(JobRunShell.java:202) ~[quartz-2.3.2.jar:?]
at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:573) ~[quartz-2.3.2.jar:?]
3.- The possible explanation for these errors:
Analysis of the Harvesting Log
Here are the key points from the log:

THREDDS Catalog read successfully:
2025-07-30T08:33:59,887 INFO [geonetwork.harvester] - Catalog read from http://thredds.geonetwork.test.socib.es/thredds/catalog/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/catalog.xml is
This confirms GeoNetwork can access the new THREDDS catalog and read its XML without issues.

Explicit OPeNDAP and ISO Services in the Catalog:
The XML catalog you attached now explicitly includes the odap (OPeNDAP) and iso service definitions:

XML

This is a significant difference from the previous catalog, which only had the ISO service defined at this level.

Successful access to OPeNDAP and ISO URLs by the harvester:
2025-07-30T08:34:00,356 INFO [geonetwork.harvester] - Opendap url is http://thredds.geonetwork.test.socib.es/thredds/dodsC/auv/glider/sl3u1064-scb_sl3u1064/L1/2024/dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:34:00,435 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/iso/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
Very important! GeoNetwork is now getting the OPeNDAP URLs and seems to be able to access them without the "host is unknown" error we had with the IP 172.16.132.22. This is due to using the hostname thredds.geonetwork.test.socib.es, which appears to resolve correctly.

The problem is still the NullPointerException in extractMetadataFromOpendapDDX!
2025-07-30T08:34:00,423 INFO [geonetwork.harvester] - Processing service: http://thredds.geonetwork.test.socib.es/thredds/dodsC/ for dep0008_sl3u1064_scb-sl3u1064_L1_2024-08-01_data_rt.nc
2025-07-30T08:34:00,492 ERROR [geonetwork.harvester] - Thrown Exception java.lang.NullPointerException during dataset processing
java.lang.NullPointerException at org.fao.geonet.kernel.harvest.harvester.thredds.Harvester.extractMetadataFromOpendapDDX(Harvester.java:1364)
This is identical to the previous problem. The INFO line stating it's "processing the OPeNDAP service" (Processing service: ... /thredds/dodsC/) doesn't mean it's doing so successfully. It's just an informative log before attempting the extraction. Immediately after, the NullPointerException occurs.

The second NullPointerException in Xml.transform also persists:
2025-07-30T08:34:28,720 ERROR [geonetwork.harvester] - null
java.lang.NullPointerException: null at org.fao.geonet.utils.Xml.transform(Xml.java:493)
As we already know, this NPE is a direct consequence of the previous one. If the first stage of metadata extraction (DDX) fails, the information passed to your XSLT transformation is incomplete or null, causing this second error.

Problem and Differences from Previous Errors
Main Problem (Unchanged): The NullPointerException in Harvester.extractMetadataFromOpendapDDX (line 1364) remains the root cause. Neither migrating to GeoNetwork 4.2.2 nor changing the THREDDS catalog (even if it explicitly includes service name="odap") has resolved this internal bug in the GeoNetwork harvester.

Why: GeoNetwork's THREDDS harvester has a DDX processing logic that's too fragile for the variations or content of the DDX served by your THREDDS server. It's a flaw in GeoNetwork's code that doesn't properly handle situations where an expected value is null or not present as the code anticipates.