gistfile1.java

import org.marc4j.marc.Record;
import org.marc4j.marc.DataField;
import org.marc4j.marc.Subfield;
import org.solrmarc.tools.Utils;

// define the base level indexer so that its methods can be called from the script.
// note that the SolrIndexer code will set this value before the script methods are called.
org.solrmarc.index.SolrIndexer indexer = null;

// Max estimation -- biggest delta of unknown dates that we'll take the
// middle of and use it as the date. 
int estimate_tolerance = 15;
// Values above this amount will be ignored, probably errors. 
int max_year = new GregorianCalendar().get(Calendar.YEAR) + 6;
int min_year = 500;
 

/* Built in getDate only looks in 260c. We will continue using 260c date if
found, but if not, look at 008 "date1". */
String jhGetDate(Record record) {
  Integer found_date = null;
  
  // first try 008.     
  field008 = indexer.getFirstFieldVal(record, "008");
  if (field008 != null && field008.length() > 11) {
    //date type 'q' means a questionable range from date1 to date2
    //'n' means date unknown. Others, we use date1. 
    char date_type = field008.charAt(6);    
    String date1str = field008.substring(7,11);
    String date2str;
    if (field008.length() > 15) {
      field008.substring(11,15);
    }
    
    
    if (date_type == 'q') {
      //it's somewhere between date1 and date2. Is that within
      //our tolerance?  Replace silly MARC u's with what they really
      // ought to be in a 'q'. If date1 or date2 don't parse, possibly
      //forget it. 
      try {
        int date1 = Integer.parseInt( date1str.replaceAll("u", "0") );
        int date2 = (date2str != null) ? Integer.parseInt( date2str.replaceAll("u", "9") ) : 9999;
        if ((date2 - date1) <= estimate_tolerance) {
          found_date = ((date2+date1)/2);
        }
      }
      catch(NumberFormatException e) {
      }
    }
    
    if (found_date == null && date_type != 'n') {
      //In type 'r', second date is original publication date, I guess
      //we'll use that?  Otherwise, date1. 
      String candidateDate;
      if (date_type == 'r' && date2str != null) {
        candidateDate = date2str;
      } else {
       candidateDate = date1str;
      }
      // deal with "u's". 
      int u_count = 0;
      while (candidateDate != null && candidateDate.matches("u$")) {
        u_count++;
        candidateDate = candidateDate.replaceFirst("u$", "0");
      }            
      try {
        found_date = Integer.parseInt(candidateDate);
        if (u_count > 0) {
          delta = Math.pow(10, count);
          if (delta <= estimate_tolerance) {
            found_date = found_date + (delta/2); 
          }
        }
      }
      catch(NumberFormatException e) {
      }
      
    }
  }    
  if (found_date == null) {
    //Try a 260c
    try {
      found_date = Integer.parseInt(indexer.getDate(record));
    }
    catch(NumberFormatException e) {
    }
  }
  
  if (found_date != null && (found_date > max_year || found_date < min_year))
    found_date = null;

  return (found_date == null) ? null : Integer.toString(found_date);
}