[JENKINS-75490] Source Code Migration to Java 17

Update trilead ssh api plugin (/jenkinsci/trilead-ssh2 library) source code to Java 17.

This should make it easier for this very old library to be maintained by developers, as the current one is difficult to maintain / enhance features. 

Since the new JVM recommendation for Jenkins is 17/21, I believe updating the source compatibility to Java 17 is reasonable and enables some new language features which help the developer experience. 

The following changes will be implemented:

• pom.xml: Source and Target set to 17 (currently unset) PR-226


• Generic types parameterized to the best of the ability (I came across one that I am not sure on how to proceed, but the code builds and current tests still pass, so I left it alone) PR-226


• Use lamda-style sytnax for classes such as Java Runnable


• Improve for loops to safer (X element : collection) from (for int x=0; x < collection.length; x++) syntax where possible


• Use new improve switch-statement syntax


• Add @​Deprectated annotations to deprecated methods


• Add @​Override annotations to implementations for interface methods PR-226


• Add @​Serial annotation to serialVersionUIDs


• Use try-with-resources blocks for closeable resources


• Make private class methods final


• Make private unchanging variables final where necessary


• Remove unnecessary type-casts PR-226


• Use static-method reference in streams, where appropriate


• Use class references instead of "strings" of class names (looking specifically at com.trilead.ssh2.crypto.cipher.BlockCipherFactory ciphers list) PR-226


• Instantiate classes with getDeclaredConstructor().newInstance() instead of the deprecated newInstance() method PR-226


• Remove unnecessary methods from child classes that have the same exact values / content as parent classes (com.trilead.ssh2.crypto.cipherDES getBlockSize() is an example) PR-226


• Fix case in Long variables (lowercase "l" -> uppercase "L") PR-226


• Use https where possible for XML files and for git clone (in the Dockerfile)

I have already done the changes above and am opening this ticket so I can submit a PR.

 

The original PR for this was.... very large, so I am breaking up the work into PRs, from most important to least.

---
Originally reported by speedythesnail, imported from: Source Code Migration to Java 17

• assignee: ifernandezcalvo
  
• status: Open
  
• priority: Minor
  
• component(s): trilead-api-plugin
  
• resolution: Unresolved
  
• votes: 1
  
• watchers: 3
  
• imported: 20251216-225446
  

Raw content of original issue

Update trilead ssh api plugin (/jenkinsci/trilead-ssh2 library) source code to Java 17.


This should make it easier for this very old library to be maintained by developers, as the current one is difficult to maintain / enhance features. 


Since the new JVM recommendation for Jenkins is 17/21, I believe updating the source compatibility to Java 17 is reasonable and enables some new language features which help the developer experience. 


The following changes will be implemented:



	
pom.xml: Source and Target set to 17 (currently unset) PR-226

	
Generic types parameterized to the best of the ability (I came across one that I am not sure on how to proceed, but the code builds and current tests still pass, so I left it alone) PR-226

	
Use lamda-style sytnax for classes such as Java Runnable

	
Improve for loops to safer (X element : collection) from (for int x=0; x < collection.length; x++) syntax where possible

	
Use new improve switch-statement syntax

	
Add @Deprectated annotations to deprecated methods

	
Add @Override annotations to implementations for interface methods PR-226

	
Add @Serial annotation to serialVersionUIDs

	
Use try-with-resources blocks for closeable resources

	
Make private class methods final

	
Make private unchanging variables final where necessary

	
Remove unnecessary type-casts PR-226

	
Use static-method reference in streams, where appropriate

	
Use class references instead of "strings" of class names (looking specifically at com.trilead.ssh2.crypto.cipher.BlockCipherFactory ciphers list) PR-226

	
Instantiate classes with getDeclaredConstructor().newInstance() instead of the deprecated newInstance() method PR-226

	
Remove unnecessary methods from child classes that have the same exact values / content as parent classes (com.trilead.ssh2.crypto.cipherDES getBlockSize() is an example) PR-226

	
Fix case in Long variables (lowercase "l" -> uppercase "L") PR-226

	
Use https where possible for XML files and for git clone (in the Dockerfile)



I have already done the changes above and am opening this ticket so I can submit a PR.


 


The original PR for this was.... very large, so I am breaking up the work into PRs, from most important to least.

environment

```
RHEL 9.5

Jenkins 2.492.2 LTS

OpenJDK 17

SSH Build Agents Plugin 3.1031.v72c6b_883b_869

SSH Credentials Plugin 355.v9b_e5b_cde5003

Development Environment:

Mac OS 15.3.2

Temurin JDK 21

IntelliJ Idea 2024.3.3
```

Review PR-226 first to separate completed migration work from the remaining items in this issue. Then inspect the trilead SSH library source, pom.xml, Dockerfile, and the listed Java constructs; done means the remaining modernization changes are applied and the existing tests still pass.

Written by the indexing model from the issue text.