The process of disassembling Java bytecode is quite simple, not as complex as native c/c++ binary.
The first step is to compile the Java source code file, which has the *.java extension through
utility that produce a *.class file from the original source code in which bytecode typically resides.
Finally, by using javap, which is a built-n utility of the JDK toolkit, we can disassemble the bytecode from the corresponding *.class file. The javap utility stores its output in *.bc file.
Note: Here remember one thing: It does display only the methods signature used in the source code, The entire source code of the Java executable, even if it contains methods related to opcodes, would be showcased by the javap –c switch
Drive:\> Javap –c LoginTest
This command dumps the entire bytecode of the program in the form of a special opcode instruction.
we shall use WinHex editor to disassemble the bytecode, which will produce the implementation logic in hexadecimal bytes, along with the strings that are manipulated in the application.