HDDS-10122. GSON requires tweaks for Java 17.

[ArafatKhan2198]

What changes were proposed in this pull request?

This issue is related to the use of GSON in the codebase and its compatibility with Java 17. The proposed solution is to replace GSON with Jackson to reduce dependencies.

Affected Modules:

The replacement of GSON with Jackson is considered for several modules in the project, including:

• KeyValueContainerMetadataInspector and TestKeyValueContainerMetadataInspector in the hadoop-hdds/container-service module.
• HddsConfServlet and EventQueue in the hadoop-hdds/framework module, along with its corresponding tests.
• Several classes in hadoop-ozone/common, especially related to multitenancy and access policies AccessPolicy
  & RangerAccessPolicy.
• Multiple integration tests and tools within the hadoop-ozone module, such as TestReconWithOzoneManager, TestOzoneShellHA, and various classes in the tools sub-module related to Ozone Shell, tenant management, and debug tools.

What is the link to the Apache JIRA

https://issues.apache.org/jira/browse/HDDS-10122?filter=-1

How was this patch tested?

Currently Draft State will be adding more classes into it.

[adoroszlai]

@ArafatKhan2198 please check test failures

[adoroszlai]

Thanks @ArafatKhan2198 for continuing work on this. There are still some test failures.

[ArafatKhan2198]

The forked CI passed successfully :- https://github.com/ArafatKhan2198/ozone/actions/runs/8308711361

[ArafatKhan2198]

@adoroszlai Could you please take a look

[adoroszlai]

Thanks @ArafatKhan2198 for the patch.

To make the change more manageable, I suggest splitting it to separate patches:

1. ozone tenant
2. ozone admin namespace
3. ozone debug
4. rest of the change, including EventQueue (still has GSON), and removal of gson as a dependency

Created HDDS-10538 with sub-tasks for this purpose.

(Please see few inline comments, too.)

[adoroszlai]

LinkedTreeMap is part of GSON. I guess if we reach this code, ClassCastException will be thrown. Probably needs to be Map, but please confirm by testing it manually.

[adoroszlai]

Can we replace LinkedTreeMap with Map here, too?

[adoroszlai]

Let's try to avoid creating a new ObjectMapper for each serialization (also in ~17 other files). Use JsonUtils:

ozone/hadoop-hdds/common/src/main/java/org/apache/hadoop/hdds/server/JsonUtils.java

Lines 59 to 74 in 238bff0

	public static String toJsonStringWithDefaultPrettyPrinter(Object obj)
	throws IOException {
	return WRITER.writeValueAsString(obj);
	}
	public static String toJsonString(Object obj) throws IOException {
	return MAPPER.writeValueAsString(obj);
	}
	public static ArrayNode createArrayNode() {
	return MAPPER.createArrayNode();
	}
	public static ObjectNode createObjectNode(Object next) {
	return MAPPER.valueToTree(next);
	}

[adoroszlai]

Thanks @ArafatKhan2198 for splitting this.