Upgrading to a newer Java release

[loleg]

Currently there are issues related to SocksSocketImpl when starting the application on a modern Java release:

Exception in thread "Thread-1" Exception in thread "Thread-0" java.lang.NoClassDefFoundError: Could not initialize class java.net.SocksSocketImpl
	at java.base/java.net.ServerSocket.setImpl(ServerSocket.java:308)
	at java.base/java.net.ServerSocket.<init>(ServerSocket.java:108)
	at com.proxeus.office.libre.conn.BootstrapSocketConnector.connect(BootstrapSocketConnector.java:39)
	at com.proxeus.office.libre.exe.LibreOffice.reconnect(LibreOffice.java:73)
	at com.proxeus.office.libre.exe.LibreOffice.<init>(LibreOffice.java:52)
	at com.proxeus.office.libre.exe.LibreOfficePool.tryNewLibreOffice(LibreOfficePool.java:340)
	at com.proxeus.office.libre.exe.LibreOfficePool.prepare(LibreOfficePool.java:243)
	at com.proxeus.office.libre.exe.LibreOfficePool.access$000(LibreOfficePool.java:35)
	at com.proxeus.office.libre.exe.LibreOfficePool$2.run(LibreOfficePool.java:132)

Which may also be related to the Jetty server .. and warnings like:

Illegal reflective access by com.proxeus.office.libre.exe.LibreOfficePool (file:/.../document-service.jar) to field java.lang.ClassLoader.sys_paths

[loleg]

After further analysis, I find that the initial warnings were due to mismatched LibreOffice versions, which need to be locked for these operations to succeed.

The second warning has to do with the newer version of Java, and is explained well here in context of Spring Framework.

[loleg]

One of the reflective access warnings is coming from a third-party dependency, parboiled via jtwig. It should possible to ignore it using this command:

--add-opens=java.base/java.lang=ALL-UNNAMED

However, from JDK 17 this will result in an unrecoverable exception.

[loleg]

Upgrade to JDK 11 seems to be successful, and I am closing this issue for now.