Add linking classes for JEP 358 and JEP 368 in Java 14

[Abhineshhh]

Description

Add linking classes in Java 14 for JEP 358 (Helpful NullPointerExceptions) and JEP 368 (Text Blocks - Second Preview) that point to their respective finalized demos in Java 17.

Details

Currently, Java 14 has demos for:

• JEP 305 (Pattern Matching for instanceof - Preview)
• JEP 359 (Records - Preview)
• JEP 361 (Switch Expressions)
• JEP 370 (Foreign-Memory Access API - Incubator)

However, two important Java 14 features are missing linking classes:

1. JEP 358 - Helpful NullPointerExceptions

   • Finalized demo exists in java17/nullpointer/NullPointerDemo.java
   • Need to create linking class in java14/jep358/

2. JEP 368 - Text Blocks (Second Preview)

   • Finalized demo exists in java17/textblock/TextBlockDemo.java
   • Need to create linking class in java14/jep368/

Tasks

• Create java14/jep358/HelpfulNullPointerExceptionsPreview.java (linking class)
• Create java14/jep368/TextBlocksSecondPreview.java (linking class)
• Update JDK14Info.json with entries for JEP 358 and 368
• Register both demos in Java14DemoLoader.java
• Ensure code compiles and runs without errors

[AloisSeckar]

Hi @Abhineshhh thank you for your observation and proposed solution. However, it is only partly true.

For Text Blocks - there is already a maintenance issue #294 - Text Blocks were finalized in JDK 15, so the current implementation from Java17 must be moved here. The issue also contains instructions to create two linking demos from preview phases.

For Helpful NullPointerExceptions - no issue yet, as I didn't prepared tasks for JDK 14 yet, but all that is need to do, is to move current old demo file from Java17 to java14/jep358 and update imports.

The reason both implementations are currently located in java17 folder, is that they are still legacy ones from the early days of the project, where I didn't have so many demos and I only had two folders for two LTS versions - 11 and 17.

Wanna work on those two?
EDIT:
There is already PR #322 for Text Blocks
I can create issue for Helpful NullPointerExceptions for you, if you want to fix this?

[Abhineshhh]

Hi @AloisSeckar
I'd love to work on moving the Helpful NullPointerExceptions demo!

[AloisSeckar]

Opened #329
Closing this