I am using POJO un/marshalling via JAXB and EclipseLink MOXy and it works great for to/from JSON notation.
I also have a need to process a CSV file (well actually a pipe-delimited file, what do they call that?) where each row gets unmarshalled into my POJOs.
Perhaps some custom Adapter scheme perhaps? ( http://www.eclipse.org/eclipselink/documentation/2.4/moxy/advanced_concepts006.htm )