# Frequently Asked Questions

## Contents

- The metrics calculated by the program do not agree with those I calculate by hand. How come?
- How can I process class files located in a jar file?
- How can I run the tool in a JDK 1.4 environment?

## The metrics calculated by the program do not agree with those I calculate by hand. How come?

The ckjm program calculates the metrics from the code appearing in the compiled bytecode files. The Java compiler optimizes away some elements of the code (for example `static final` fields, and these do not take part in the calculations. You may want to consult the disassembled code (using a command like `javap -c -private` to see what elements ckjm takes into account.

## How can I process class files located in a jar file?

See the documentation section titled Using Pipelines to Select Classes.

## How can I run the tool in a JDK 1.4 environment?

You can use the open source tool retroweaver to create a backwards-compatible jar file. (Suggested by Paul King).

Contents | « Previous Next (Contributors) »