jclassinfo binary package in Ubuntu Bionic amd64

 jclassinfo reads Java class files and extract useful information
 from them, such as:
   * the classes/methods/constants/fields provided
   * their dependencies
   * the version of the virtual machine necessary to run them
   * a full disassembly of the bytecode
   * other attributes
 .
 Its main advantage over other similar programs is that it is written
 in C, which makes it much faster and more suitable for scripting.

Source package