--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/goodjava/lucene/queryparser/MultiFieldParser.java	Fri Mar 20 10:58:53 2020 -0600
@@ -0,0 +1,86 @@
+package goodjava.lucene.queryparser;
+
+import java.util.Map;
+import java.util.HashMap;
+import org.apache.lucene.search.Query;
+import org.apache.lucene.search.BooleanQuery;
+import org.apache.lucene.search.BooleanClause;
+import org.apache.lucene.search.SortField;
+import goodjava.parser.ParseException;
+
+
+public class MultiFieldParser implements FieldParser {
+
+	/**
+	 * maps field name to FieldParser
+	 */
+	public final Map<String,FieldParser> fields = new HashMap<String,FieldParser>();
+	public boolean allowUnspecifiedFields = false;
+	private final FieldParser defaultFieldParser;
+	private final String[] defaultFields;
+
+	public MultiFieldParser() {
+		this.defaultFieldParser = null;
+		this.defaultFields = null;
+	}
+
+	public MultiFieldParser(FieldParser defaultFieldParser,String... defaultFields) {
+		this.defaultFieldParser = defaultFieldParser;
+		this.defaultFields = defaultFields;
+		for( String field : defaultFields ) {
+			fields.put(field,defaultFieldParser);
+		}
+	}
+
+	@Override public Query getQuery(SaneQueryParser qp,String field,String query) throws ParseException {
+		if( field == null ) {
+			if( defaultFieldParser == null )
+				throw qp.exception("no defaults were specified, so a field is required");
+			if( defaultFields.length == 1 )
+				return defaultFieldParser.getQuery(qp,defaultFields[0],query);
+			BooleanQuery bq = new BooleanQuery();
+			for( String f : defaultFields ) {
+				bq.add( defaultFieldParser.getQuery(qp,f,query), BooleanClause.Occur.SHOULD );
+			}
+			return bq;
+		} else {
+			FieldParser fp = fields.get(field);
+			if( fp != null )
+				return fp.getQuery(qp,field,query);
+			if( allowUnspecifiedFields )
+				return defaultFieldParser.getQuery(qp,field,query);
+			throw qp.exception("unrecognized field '"+field+"'");
+		}
+	}
+
+	@Override public Query getRangeQuery(SaneQueryParser qp,String field,String minQuery,String maxQuery,boolean includeMin,boolean includeMax) throws ParseException {
+		if( field == null ) {
+			if( defaultFieldParser == null )
+				throw qp.exception("no defaults were specified, so a field is required");
+			if( defaultFields.length == 1 )
+				return defaultFieldParser.getRangeQuery(qp,defaultFields[0],minQuery,maxQuery,includeMin,includeMax);
+			BooleanQuery bq = new BooleanQuery();
+			for( String f : defaultFields ) {
+				bq.add( defaultFieldParser.getRangeQuery(qp,f,minQuery,maxQuery,includeMin,includeMax), BooleanClause.Occur.SHOULD );
+			}
+			return bq;
+		} else {
+			FieldParser fp = fields.get(field);
+			if( fp != null )
+				return fp.getRangeQuery(qp,field,minQuery,maxQuery,includeMin,includeMax);
+			if( allowUnspecifiedFields )
+				return defaultFieldParser.getRangeQuery(qp,field,minQuery,maxQuery,includeMin,includeMax);
+			throw qp.exception("field '"+field+"' not specified");
+		}
+	}
+
+	@Override public SortField getSortField(SaneQueryParser qp,String field,boolean reverse) throws ParseException {
+		FieldParser fp = fields.get(field);
+		if( fp != null )
+			return fp.getSortField(qp,field,reverse);
+		if( allowUnspecifiedFields )
+			return defaultFieldParser.getSortField(qp,field,reverse);
+		throw qp.exception("field '"+field+"' not specified");
+	}
+
+}