I want to find the version of a .class file

Question

Is there any way to find the java version from a compiled java .class file ?

Answer 1

You're looking for this on the command line (for a class called MyClass):

javap -verbose MyClass

You want the major version from the results. Here are some example values:

Java 1.2 uses major version 46
Java 1.3 uses major version 47
Java 1.4 uses major version 48
Java 5 uses major version 49
Java 6 uses major version 50
Java 7 uses major version 51

Answer 2

You may try to get the version of your class using:

javap -verbose help

The javap comes with jdk and the verbose tells the version.

> javap -verbose help
Compiled from "help.java"
public class help
  SourceFile: "help.java"
  minor version: 0
  major version: 46