Need to find if the API's which we are using are depreciated from Jira V7.4 to 8.13/8.20

[Mohan Sundar]

Dear Community Members,

I hope everyone is safe and well. I appreciate your support on this.

I reached out to Atlassian Support Team but was unable to get the required information as I was redirected to reach out to Community forum. Atlassian's Reply: "I reached out to our developers but it seems that the JIRA REST Java Client Library is part of the ecosystem projects that are not owned by our developers. We did some research but we were not able to identify the repos where these projects are located. As you may understand, this is out of support and I am afraid we’ll not be able to come up with an answer, unfortunately. It is mentioned in this document to reach out to the community for any questions"

This is my question on upgrade/migration to DC but this is based on external integrated systems we have.

Our Development team is using the Java/C# libraries from Jira  for two purpose:
1. Portal: Which will read and write from Jira
2. Dashboard: To show various metrics in customized way.

Portal/Dashboard Dependency:
1. Rest API Depreciation from v7.4 to v8.13
2. I understand that DC is also a Server version just that it supports multi nodes but Rest API for Jira Server and Jira Data Center are they different?
3. Any changes to Java/C# Library from from v7.4 to v8.13
4. We have 2 external systems that read/write information from Jira. We would like to get a confirmation from Atlassian if any of these external systems will be impacted. I have provided the methods we use for integration.

I would like to get a confirmation if the below libraries has any changes/depreciated

C# Library from Atlassian
Name: Atlassian.Jira

Java Library from Atlassian
Name: jira-rest-java-client-core

Maven Dependency
<dependency>
<groupId>com.atlassian.jira</groupId>
<artifactId>jira-rest-java-client-core</artifactId>
<version>5.1.2-2bd0a62e</version>
</dependency>

Imports we are using as of now from this library
import com.atlassian.jira.rest.client.api.JiraRestClient;
import com.atlassian.jira.rest.client.api.domain.Issue;
import com.atlassian.jira.rest.client.api.domain.SearchResult;
import com.atlassian.jira.rest.client.api.domain.Issue;
import com.atlassian.jira.rest.client.api.domain.SearchResult;
import com.atlassian.jira.rest.client.api.AuthenticationHandler;
import com.atlassian.jira.rest.client.api.JiraRestClient;
import com.atlassian.jira.rest.client.auth.BasicHttpAuthenticationHandler;
import com.atlassian.jira.rest.client.internal.async.AsynchronousJiraRestClient;
import com.atlassian.jira.rest.client.internal.async.AsynchronousJiraRestClientFactory;
import com.atlassian.jira.rest.client.internal.async.DisposableHttpClient;

This is the Java API from library we are using for executing JQL commands using search

Promise issuePromise = restClient.getSearchClient().searchJql(jql,maxResults,startAt,null);

This is the Java API from library we are using for getting issues we are using
Promise issuePromise = restClient.getIssueClient().getIssue(issueKey);

For authentication
import com.atlassian.jira.rest.client.auth.BasicHttpAuthenticationHandler;
new BasicHttpAuthenticationHandler(username, password),socketTimeoutInSec)

Jira Rest client we are using
import com.atlassian.jira.rest.client.internal.async.AsynchronousJiraRestClient;
new AsynchronousJiraRestClient(serverUri, httpClient);

Best Regards,
Mohana Sundar J.