深入解析：JDK1.7 class文件常量池与方法引用

CA FE BA BE  魔幻数  
00 00   次版本
00 32   主版本 50， JDK1.7
00 0F   常量池 15个
0A      constant_methodref(10) constant_pool[1].tag
00 03   constant_pool[1].class_index  -> 3
00 0C   constant_pool[1].name_and_type_index -> 12
07     constant_class(7) constant_pool[2].tag
00 0D  constant_pool[2].name_index -> 13
07      constant_class(7) constant_pool[3].tag
00 0E  constant_pool[3].name_index -> 14 
01  constant_utf8_info(1) constant_pool[4].tag 
00 06  constant_pool[4].length -> 6   
3C 69 6E 69 74 3E  constant_pool[4].bytes[length] -> "<init>"
01  constant_utf8_info(1) constant_pool[5].tag  
00 03  constant_pool[5].length -> 3  
28 29 56  constant_pool[5].bytes[length] -> "()V"
01  constant_utf8_info(1) constant_pool[6].tag   
00 04  constant_pool[6].length -> 4   
43 6F 64 65  constant_pool[6].bytes[length] -> "Code"
01  constant_utf8_info(1) constant_pool[7].tag    
00 0F  constant_pool[7].length -> 15    
4C 69 6E 65 4E 75 6D 62 65 72 54 61 62 6C 65   constant_pool[7].bytes[length] -> "LineNumberTable"
01  constant_utf8_info(1) constant_pool[8].tag 
00 0D  constant_pool[8].length -> 13  
64 6F 4D 61 74 68 46 6F 72 65 76 65 72   constant_pool[8].bytes[length] -> "doMathForever"
01  constant_utf8_info(1) constant_pool[9].tag  
00 0D  constant_pool[9].length -> 13
53 74 61 63 6B 4D 61 70 54 61 62 6C 65   constant_pool[9].bytes[length] ->  "StackMapTable"
01  constant_utf8_info(1) constant_pool[10].tag 

00 0A  constant_pool[10].length -> 10
53 6F 75 72 63 65 46 69 6C 65    constant_pool[10].bytes[length] ->  "SourceFile" 
01  constant_utf8_info(1) constant_pool[11].tag  
00 08  constant_pool[11].length -> 8 
41 63 74 2E 6A 61 76 61  constant_pool[11].bytes[length] ->  "Act.java" 
0C  constant_NameAndType(12) constant_pool[12].tag   
00 04  constant_pool[12].name_index -> 4  
00 05  constant_pool[12].descriptor_index -> 5  
01  constant_utf8_info(1) constant_pool[13].tag 
00 03  constant_pool[13].length -> 3 
41 63 74  constant_pool[13].bytes[length] ->  "Act"
01  constant_utf8_info(1) constant_pool[14].tag  
00 10  constant_pool[14].length -> 16  
6A 61 76 61 2F 6C 61 6E 
67 2F 4F 62 6A 65 63 74  constant_pool[14].bytes[length] ->  "java/lang/Object"
00 20  access_flags ACC_SUPER 固定值,为了与老版本的java编译器兼容
00 02  this_class constant_pool[constant_pool[2].name_index] -> Act     （constant_utf8_info[13]）
00 03  super_class constant_pool[constant_pool[3].name_index] -> "java/lang/Object"  （constant_utf8_info[14]）
00 00  interfaces_count 0
00 00 fields_count  0
00 02  methods_count 2
-----------Method[0]---------------------------------------------
00 00  access_flags 编译器调用
00 04  name_indiex constant_pool[4].bytes[length] -> "<init>"
00 05  descriptor_index constant_pool[5].bytes[length] -> "()V"
00 01  attributes_count 1
00 06  attribute_name_index constant_pool[6].bytes[length] -> "Code"
00 00 00 1D  attribute_length 29
00 01  max_stack 1
00 01  max_locals 1