Add support to get metatada resource json object into the index.

[ianwallen]

Add support to get metatada resource json object into the index.
Changed some of the conversion tool for xml to json and vice versa so that they support json arrays and other json nodes. Also fixed issue with indexer not being triggered after resources are uploaded.

Indexing resource information such as size and last modified data is helpful to be able to search on resources that were recently modified or to be able to search or summarize metadata content size quickly.

This is sample json that would be added to the index.

                    "fileStore": [
                        {
                            "lastModification": "2025-09-23T15:41:21.592+00:00",
                            "size": 450041,
                            "url": "http://localhost:8080/geonetwork/srv/api/records/37aecae5-7783-4274-b595-df02aa003ac3/attachments/test.txt",
                            "visibility": "PUBLIC"
                        },
                        {
                            "lastModification": "2023-01-12T14:40:34.000+00:00",
                            "size": 152545,
                            "url": "http://localhost:8080/geonetwork/srv/api/records/37aecae5-7783-4274-b595-df02aa003ac3/attachments/ecdc_thumbnail_radar-composite.jpg",
                            "visibility": "PUBLIC"
                        },
                        {
                            "lastModification": "2025-09-23T15:41:08.212+00:00",
                            "size": 13754,
                            "url": "http://localhost:8080/geonetwork/srv/api/records/37aecae5-7783-4274-b595-df02aa003ac3/attachments/test.json",
                            "visibility": "PUBLIC"
                        }
                    ],

Checklist

• I have read the contribution guidelines
• Pull request provided for main branch, backports managed with label
• Good housekeeping of code, cleaning up comments, tests, and documentation
• Clean commit history broken into understandable chucks, avoiding big commits with hundreds of files, cautious of reformatting and whitespace changes
• Clean commit messages, longer verbose messages are encouraged
• API Changes are identified in commit messages
• Testing provided for features or enhancements using automatic tests
• User documentation provided for new features or enhancements in manual
• Build documentation provided for development instructions in README.md files
• Library management using pom.xml dependency management. Update build documentation with intended library use and library tutorials or documentation

[tylerjmchugh]

Tested, works as expected

[juanluisrp]

I've added some comments and suggestions. Can you check them if make sense, please?

[juanluisrp]

I'm adding here a new test for JSON object.

Suggested change

	}
	}
	/**
	* Tests the conversion of a JSON object to an XML representation and validates
	* the resulting XML against an expected XML representation.
	*/
	@Test
	public void testObjectConversion() throws Exception {
	String jsonString = "{\"Test\":\"value\", \"nestedObject\": {\"nestedField\": 433}}";
	String expectedElement = "<root><Test>value</Test><nestedObject><nestedField>433</nestedField></nestedObject></root>";
	Element xmlFromJSON = Xml.getXmlFromJSON(jsonString);
	Diff diff = DiffBuilder
	.compare(Input.fromString(expectedElement))
	.withTest(Input.fromString(Xml.getString(xmlFromJSON)))
	.withNodeMatcher(new DefaultNodeMatcher(ElementSelectors.byName))
	.normalizeWhitespace()
	.ignoreComments()
	.checkForSimilar()
	.build();
	assertFalse(diff.toString(), diff.hasDifferences());
	}

[juanluisrp]

I think it isn't a good idea from the point of view of the performance to create a new TransformerFactory every time the method is called. Shouldn't we use TransformerFactoryFactory.getTransformerFactory() instead that uses a singleton?

Suggested change

	TransformerFactory tf = TransformerFactory.newInstance();
	TransformerFactory tf = TransformerFactoryFactory.getTransformerFactory();

[juanluisrp]

Creating an ObjectMapper every time this method is called is inefficient. Maybe we can move it to be a member of the class?

[juanluisrp]

Why in MEFVisitor v.indexMetadata() is called in visit() but in MEF2Visitor is called in handleXml() method?

[tylerjmchugh]

It just needed to follow the handleBin() call which was already in visit() for MEFVisitor and handleXml() for MEF2Visitor before these changes