无需编辑器，只要有 JDK
Windows
javap -v Demo.class | finstr version
Linux
javap -v Demo.class | grep version
minor version: 0
major version: 52
od -x UniqueValidator.class |awk 'NR==1'
0000000 feca beba 0000 3400 7c01 000a 0062 07be
| version | Hex | major |
|---|---|---|
| 6 | 2 ^ 5 = 32 | 10 × 5 = 50 |
| 7 | 33 | 51 |
| 8 | 34 | 52 |