MARC4J provides an easy to use API for working with MARC (binary), MARCXML, MARC JSON in Java. MARC stands for MAchine Readable Cataloging and is a widely used exchange format for bibliographic data. MARCXML provides a loss-less conversion between MARC (MARC21 but also other formats like UNIMARC) and XML.

Features

The MARC4J library includes:

...

JSON representation of marc record entity

{
  "leader": "00508cjm a22001813 4500",
 "fields": [
    {
      "001": "10062588"
 },
 {
      "005": "20171013073237.0"
 },
 {
      "007": "sd fsngnnmmneu"
 },
 {
      "008": "170825s2017 xx nn n zxx d"
 },
 {
      "024": {
        "subfields": [
          {
            "a": "00190295755553"
 },
 {
            "2": "gtin-14"
 }
        ],
 "ind1": "7",
 "ind2": " "
 }
    },
 {
      "024": {
        "subfields": [
          {
            "a": "190295755553"
 }
        ],
 "ind1": "1",
 "ind2": " "
 }
    },
 {
      "035": {
        "subfields": [
          {
            "a": "(OCoLC)1002130878"
 }
        ],
 "ind1": " ",
 "ind2": " "
 }
    },
 {
      "035": {
        "subfields": [
          {
            "a": "10062588"
 }
        ],
 "ind1": " ",
 "ind2": " "
 }
    },
 {
      "040": {
        "subfields": [
          {
            "a": "BTCTA"
 },
 {
            "b": "eng"
 },
 {
            "c": "BTCTA"
 }
        ],
 "ind1": " ",
 "ind2": " "
 }
    },
 {
      "100": {
        "subfields": [
          {
            "a": "Rossi, Daniele"
 }
        ],
 "ind1": "1",
 "ind2": " "
 }
    },
 {
      "245": {
        "subfields": [
          {
            "a": "Saint-Saens: Organ Symphony and Carnival of The Animals"
 }
        ],
 "ind1": "0",
 "ind2": "0"
 }
    },
 {
      "260": {
        "subfields": [
          {
            "b": "Wea Corp"
 },
 {
            "c": "2017."
 }
        ],
 "ind1": " ",
 "ind2": " "
 }
    },
 {
      "948": {
        "subfields": [
          {
            "a": "20171013"
 },
 {
            "b": "m"
 },
 {
            "d": "batch"
 },
 {
            "e": "lts"
 },
 {
            "x": "deloclcprefix"
 }
        ],
 "ind1": "2",
 "ind2": " "
 }
    }
  ]
}

Code snippet

to parse MARC file and print all information to console

public class App {

    public static void main(String args[]) throws Exception {

        // path to .mrc file
 String path = "";

 // Input Stream from file
 InputStream in = new FileInputStream(path);
 MarcReader reader = new MarcStreamReader(in);
 while (reader.hasNext()) {
            Record record = reader.next();

 Leader leader = record.getLeader();

 List<ControlField> controlFields = record.getControlFields();
 List<DataField> dataFields = record.getDataFields();

 System.out.println();
 System.out.println("LEADER: " + leader);
 System.out.println("Control fields: ");
 controlFields.forEach(System.out::println);
 System.out.println("Data fields: ");
 dataFields.forEach(System.out::println);
 System.out.println();
 }
    }
}

Transform MARCJson to MARCXML.

...