javap 简介

Disassembles one or more class files.
及反汇编一个或多个class文件

使用介绍

javap [options] classfile ...
classfile 使用 classpath下的或者classfile 描述本身是全路径的。
options 是命令行参数
javap 的输出默认是到 stdout

Options 详解

• -help --help -?

• -version
  print release information

• -l
  prints line and local variable tables

• -public
  shows only public classes and members

• -protected
  Shows only protected and public classes and members.

• -private -p
  Shows all classes and members.

• -Joption
  Passes the specified option to the JVM

• -s
  Prints internal type signatures.

• -sysinfo
  Shows system information (path, size, date, MD5 hash) of the class being processed.

• -constants
  Shows static final constants.

• -c
  Prints disassembled code, for example, the instructions that comprise the Java bytecodes, for each of the methods in the class.

• -verbose
  Prints stack size, number of locals and arguments for methods.

• -classpath path
  Specifies the path the javap command uses to look up classes. Overrides the default or the CLASSPATH environment variable when it is set.

• -bootclasspath path
  Specifies the path from which to load bootstrap classes. By default, the bootstrap classes are the classes that implement the core Java platform located in jre/lib/rt.jar and several other JAR files.

• -extdir dirs
  Overrides the location at which installed extensions are searched for. The default location for extensions is the value of java.ext.dirs.

使用下来 javap -verbose 的使用更有意义一点