number

major version number of the JAVA class file format Java SE 10 = 54 (0x36 hex) Java SE 9 = 53 (0x35 hex) Java SE 8 = 52 (0x34 hex) Java SE 7 = 51 (0x33 hex) Java SE 6.0 = 50 (0x32 hex) Java SE 5.0 = 49 (0x31 hex) JDK 1.4 = 48 (0x30 hex) JDK 1.3 = 47 (0x2F hex) JDK 1.2 = 46 (0x2E hex) JDK 1.1 = 45 (0x2D hex)