JVM之Class文件结构

男娘i 2022-03-31 08:08 204阅读 0赞

# 类型解析 #

*  ### u4   在进制里面占4个字节 ###
 *  ### u2   在进制里面占2个字节 ###

# Class文件格式 #

<table> 
 <thead> 
  <tr> 
   <th style="width:139px;">类型</th> 
   <th style="width:342px;">名称</th> 
   <th>数量</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:139px;">u4</td> 
   <td style="width:342px;">magic</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">minor_version</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">major_version</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">constant_pool_count</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">cp_info</td> 
   <td style="width:342px;">constant_pool</td> 
   <td>constant_pool_count的数量</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">access_flags</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">this_class</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">super_class</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">interfaces_count</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">interfaces</td> 
   <td>interfaces_count的数量</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">fields_count</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">field_info</td> 
   <td style="width:342px;">fileds</td> 
   <td>fields_count的数量</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">methods_count</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">methods_info</td> 
   <td style="width:342px;">methods</td> 
   <td>methods_count的数量</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">u2</td> 
   <td style="width:342px;">attributes_count</td> 
   <td>1</td> 
  </tr> 
  <tr> 
   <td style="width:139px;">attributes_info</td> 
   <td style="width:342px;">attributes</td> 
   <td>attributes_count的数量</td> 
  </tr> 
 </tbody> 
</table>

# 魔数(指向magic) #

# Class文件版本号(指向minor\_version、major\_version) #

# 常量池类型(指向constant\_pool\_count、constant\_pool) #

# 访问标志(指向access\_flags) #

# 类索引、父类索引、接口索引集合(指向this\_class、super\_class、interfaces\_count、interfaces) #

# 字段表集合(指向fields\_count、fileds) #

# 方法表集合(指向methods\_count、methods) #

# 属性表集合(指向attributes、attributes) #