Run client/server under any java version and play on public servers (macOS M1/2/3 fix and other)

[JayDi85]

For macOS users: current releases are fully compatible and haven't any freezes anymore, so you don't need to use java replacement

Current public servers works under java 8 and it's incompatible with java 9+ clients by default.

On server connection it will show errors like:

• java.lang.reflect.InaccessibleObjectException: Unable to make private void java.io.ObjectOutputStream.clear() accessible: module java.base does not "opens java.io" to unnamed module

There is possible a solution to run compatible client under any java version. It can be usefull for macOS with M1/2/3 machines who can't run java 8 due constant freeze (#12431). Added: not actual anymore cause macOS freezes fixed with non-blocking in last release #12825

Instruction:

1. Download and install current client from http://xmage.today/ (follow site instructions);
2. Run launcher and press update button - it will download java and other files;
3. Open launcher's "settings -> java -> client options" and add that additional params to the end (keep spaces too):
   • --add-opens=java.base/java.io=ALL-UNNAMED
   • 
4. Find and download latest OpenJDK version from any sites like https://adoptium.net/temurin/releases/
   • use stable/lts version first like java 17 or 21;
   • if nothing helps then use java 24 from here;
5. Extract java files to temp folder and copy that files to xmage's "launcher\java\jre1.8.0_201" folder -- make sure you keep same files structure;
6. Now run client from a launcher again and play on any public servers;
7. Warning, if you see pixelated images, icons and text then must disabled Windows's DPI-aware feature or add the follow additional launcher param for java - client:
   • -Dsun.java2d.uiScale=1.0

[JayDi85]

If you see pixelated images, icons and text then must disabled Windows's DPI-aware feature or add the follow additional launcher param for settings - java - client:

• -Dsun.java2d.uiScale=1.0

[JayDi85]

Recommended java versions for maximum client-server compatibility (read "java 21" as any java 9+):

• Server on java 8 - ✅ work by default
  • Clients on java 8 - ✅ work by default
  • Clients on java 21 - ⚠️ require add-opens and uiScale
• Server on java 21 - ⚠️ require add-opens
  • Clients on java 8 - ✅ work by default, but server must run with add-opens
  • Clients on java 21 - ⚠️ require add-opens and uiScale

P.S. Look at starting comment for add-opens and uiScale params usage.