List of Java class file format major version numbers?

Robert Mark Bram picture Robert Mark Bram · Feb 7, 2012 · Viewed 138.5k times · Source

I saw this list of major version numbers for Java in another post:

  • Java 1.2 uses major version 46
  • Java 1.3 uses major version 47
  • Java 1.4 uses major version 48
  • Java 5 uses major version 49
  • Java 6 uses major version 50
  • Java 7 uses major version 51
  • Java 8 uses major version 52
  • Java 9 uses major version 53
  • Java 10 uses major version 54
  • Java 11 uses major version 55
  • Java 12 uses major version 56
  • Java 13 uses major version 57
  • Java 14 uses major version 58
  • Java 15 uses major version 59

Where does this list come from? Is there a specific reference for this? Preferably something that shows minor versions too?

Answer

Michael picture Michael · Feb 7, 2012

These come from the class version. If you try to load something compiled for java 6 in a java 5 runtime you'll get the error, incompatible class version, got 50, expected 49. Or something like that.

See here in byte offset 7 for more info.

Additional info can also be found here.