For certain features Jalopy must resolve the type information in source files in order to determine what action to take. Depending on the settings, it therefore might be essential that the class path is correctly configured and the file/project clean before formatting is applied. This is usually a non-issue when working in an IDE as here the project configuration and build-in type system is automatically leveraged and requires no user intervention in order to make type resolution work. But for the headless plug-ins, care must be taken to correctly setup their invocation. If you want to use any of the below mentioned features, you must provide the correct class path in order to experience the desired results.