java 各个版本的对应关系

JDK版本号	Class版本号	16进制
1.1	45.0	00 00 00 2D
1.2	46.0	00 00 00 2E
1.3	47.0	00 00 00 2F
1.4	48.0	00 00 00 30
1.5	49.0	00 00 00 31
1.6	50.0	00 00 00 32
1.7	51.0	00 00 00 33
1.8	52.0	00 00 00 34
9	53.0	00 00 00 35
10	54.0	00 00 00 36
11	55.0	00 00 00 37
12	56.0	00 00 00 38
13	57.0	00 00 00 39
14	58.0	00 00 00 3a
15	59.0	00 00 00 3b
16	60.0	00 00 00 3c
17	61.0	00 00 00 3d
18	62.0	00 00 00 3e