number of instructions in foo.class java file

Question

I have binary of a java program say foo.class. Is it possible that I count the number of instructions in that class file ? or do I have to have the source code to count the number of instructions.

Answer 1

Just disassemble the class using javap. The -c option

...prints out disassembled code, i.e., the instructions that comprise the Java bytecodes, for each of the methods in the class. These are documented in the Java Virtual Machine Specification