How to analyze Java class files?

Question

I have a Java .class-file. Now I'd like to find out which methods an fields it provides to the outside world.

I'd like to get a list of all methods and fields plus their visibility. The output could be:

1) final static String CONST = "Test"
2) final public void print(String)
3) protected(com.stackoverflow.package) void pprint(String)

Answer 1

Use javap

javap DocFooter.class

To get the static final constants

javap -constants DocFooter.class

Check this out

Answer 2

For every class with in the JVM there is object of the type Class. You can query on this object to get all the info on that particular class.

Class myClass = MyClass.class Method method[] = myClass.getDeclaredMethods();

Refer to Java doc for further info, http://docs.oracle.com/javase/7/docs/api/java/lang/Class.html

If you just want to look at the class content then there are editors like djCompiler etc which does a pretty good job.