Java version update?

[Burt Harris]

Hello Sam, long time no talk.

I was trying to get back into this project today. I've learned a few things that could improve it. As usual, I'm doing it on a new machine, and getting Java to work is always the sore spot for me. I tried to do it with winget, and ended up with the versions shown below. It seems like this project is set up for much older versions. Looking for your guidance on if we should be using a newer version of Java.

openjdk 16.0.1 2021-04-20
OpenJDK Runtime Environment AdoptOpenJDK-16.0.1+9 (build 16.0.1+9)
OpenJDK 64-Bit Server VM AdoptOpenJDK-16.0.1+9 (build 16.0.1+9, mixed mode, sharing)
 
javac 16.0.1

Apache Maven 3.6.3 (cecedd343002696d0abb50b32b541b8a6ba2883f)
Maven home: C:\Program Files\Apache\Maven\bin\..
Java version: 16.0.1, vendor: AdoptOpenJDK, runtime: C:\Program Files\AdoptOpenJDK\jdk-16.0.1.9-hotspot
Default locale: en_US, platform encoding: Cp1252
OS name: "windows 10", version: "10.0", arch: "amd64", family: "windows"

Error messages from npm install begin maven complaining:

> mvn verify

[INFO] Scanning for projects...
[INFO]
[INFO] ---------------< com.tunnelvisionlabs:antlr4-typescript >---------------
[INFO] Building ANTLR 4 Target TypeScript 4.9.0-SNAPSHOT
[INFO] --------------------------------[ jar ]---------------------------------
[INFO]
[INFO] --- maven-enforcer-plugin:1.2:enforce (enforce-maven) @ antlr4-typescript ---
[INFO]
[INFO] --- maven-resources-plugin:2.6:resources (default-resources) @ antlr4-typescript ---
[INFO] Using 'UTF-8' encoding to copy filtered resources.
[INFO] Copying 1 resource
[INFO]
[INFO] --- maven-compiler-plugin:3.8.1:compile (default-compile) @ antlr4-typescript ---
[INFO] Changes detected - recompiling the module!
[INFO] Compiling 2 source files to C:\Code\antlr4ts\tool\target\classes
[INFO] -------------------------------------------------------------
[WARNING] COMPILATION WARNING :
[INFO] -------------------------------------------------------------
[WARNING] bootstrap class path not set in conjunction with -source 6
[INFO] 1 warning
[INFO] -------------------------------------------------------------
[INFO] -------------------------------------------------------------
[ERROR] COMPILATION ERROR :
[INFO] -------------------------------------------------------------
[ERROR] Source option 6 is no longer supported. Use 7 or later.
[ERROR] Target option 6 is no longer supported. Use 7 or later.
[INFO] 2 errors
[INFO] -------------------------------------------------------------
[INFO] ------------------------------------------------------------------------
[INFO] BUILD FAILURE
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  0.919 s
[INFO] Finished at: 2021-05-10T17:16:00-07:00
[INFO] ------------------------------------------------------------------------
[ERROR] Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:3.8.1:compile (default-compile) on project antlr4-typescript: Compilation failure: Compilation failure:
[ERROR] Source option 6 is no longer supported. Use 7 or later.
[ERROR] Target option 6 is no longer supported. Use 7 or later.
[ERROR] -> [Help 1]
[ERROR]
[ERROR] To see the full stack trace of the errors, re-run Maven with the -e switch.
[ERROR] Re-run Maven using the -X switch to enable full debug logging.
[ERROR]
[ERROR] For more information about the errors and possible solutions, please read the following articles:
[ERROR] [Help 1] http://cwiki.apache.org/confluence/display/MAVEN/MojoFailureException

Aside question: Has the Antlr4 implementation changed so that it can be self-hosted? The Java tool dependency really has me bumming.