Java Tools Tutorials - Herong's Tutorial Examples - v6.21, by Dr. Herong Yang
javap - Java Disassembler Command and Options
This section describes what are the commonly used command line options for the Java bytecode class disassembler - 'javap' tool.
What Is "javap"? "javap" is a command line tool that reads Java bytecode class files and disassembles them.
"javap" has been included in JDK installation since JDK 1.0. And it is represented by the %java_home%\bin\javap.exe program file.
"javap" command has the following syntax:
javap [options] classnames
where "options" is a list of options and "classnames" is a list of Java class names.
If you have %java_home%\bin directory included in "path" the environment variable, you can run "javap -help" to see the complete list of all options:
herong> javap -help Usage: javap <options> <classes> where possible options include: -help --help -? Print this usage message -version Version information -v -verbose Print additional information -l Print line number and local variable tables -public Show only public classes and members -protected Show protected/public classes and members -package Show package/protected/public classes and members (default) -p -private Show all classes and members -c Disassemble the code -s Print internal type signatures -sysinfo Show system info (path, size, date, MD5 hash) of class being processed -constants Show final constants --module <module>, -m <module> Specify module containing classes to be disassembled --module-path <path> Specify where to find application modules --system <jdk> Specify where to find system modules --class-path <path> Specify where to find user class files -classpath <path> Specify where to find user class files -cp <path> Specify where to find user class files -bootclasspath <path> Override location of bootstrap class files GNU-style options may use = instead of whitespace to separate the name of an option from its value. Each class to be shown may be specified by a filename, a URL, or by its fully qualified class name. Examples: path/to/MyClass.class jar:file:///path/to/MyJar.jar!/mypkg/MyClass.class java.lang.Object
For more information, see "javap" reference page at https://docs.oracle.com/en/java/javase/15/docs/specs/man/javap.html.
Table of Contents